BACKGROUND OF THE INVENTION

1. FIELD OF THE INVENTION

This invention relates to a method for preparing lubricating oils by predicting performance, perceptual, chemical or physical properties of streams entering or exiting units in the lubes manufacturing process using a combination of gas chromatography and mass spectrometry.

2. DESCRIPTIONOFTHERELATEDART

Refineries and chemical plants typically control processing of various component streams and certain additives through the use of both on-line analyzers and off-line laboratory analyses to provide quality information. These quality parameters (chemical composition, physical or perceptual or performance properties) are then fed back into a process control computer which contains control software or algorithms which control refinery or chemical plant hardware (distillation towers or proportional flow control valves). The control programs are typically executed more than three times per hour and their output is used to control either processes or proportional flow valves to vary the quality ofthe finished product which can either go to tankage or directly to pipelines and terminals, trucks, or to ship-loading facilities. Multiple on-line analyzers are typically required for this process control.

Gas chromatograph has been used to predict physical and performance properties of hydrocarbon mixtures boiling in the gasoline range. Crawford and Hellmuth, Fuel, 1990, 69, 443-447, describe the use of gas chromatography and principal components regression analysis to predict the octane values for gasolines blended from different refinery streams. Japanese laid-open patent application JP 03- 100463 relates to a method of estimating the cetane number for fuel oils by separating an oil sample into its components using gas chromatography, measuring the signal strength of ion intensities at characteristic masses in the mass spectrum, and correlating these ion intensities to cetane number using multiple regression analysis.

Combined gas chromatography/mass spectrometry (GS/MS) analysis has been done on crude oils. U.S. Patent 5,1 19,315 discloses a method for aligning sample

data such as a mass chromatogram with reference data from a known substance. Williams et al, 12th European Assoc. Organic Geochem., Organic Geochem. Int. Mtg. (Germany 09/16-20/85); Organic Geochemistry 1986, Vol. 10 (1-3) 451-461, discusses the biodegradation of crude oils as measured by GC/MS analysis.

It would be desirable to have a single analyzer means for rapidly measuring chemical or physical properties of intermediate streams in the manufacturing process and/or lube oil products and using these properties to control units within the manufacturing process and/or product quality.

SUMMARY OF THE INVENTION

This invention relates to a process for controlling the manufacture of lubricating oils from a feed having a boiling point of about 350°C or greater by the steps of introducing the feed into a distillation unit, separating the feed into light, medium and heavy distillates, introducing the distillates into an extraction unit, extracting the distillates to produce raffinates, introducing the raffinates into a dewaxing unit and dewaxing the raffinates to produce lubricating oils, said process comprising:

(a) obtaining samples of at least one of lubricating oil, feed, distillate and raffinate;

(b) selecting at least one physical, chemical, perceptual or performance property of at least one of lubricating oil, feed, distillate and raffinate;

(c) selecting reference samples, said reference samples containing characteristic compound types present in the at least one lubricating oil, feed, distillate and raffinate and which have known values for the property or properties selected in step (b);

(d) producing a training set by the steps of:

(1) injecting each reference sample into a gas chromatograph which is interfaced to a mass spectrometer thereby causing at least a partial separation ofthe

hydrocarbon mixture into constituent chemical components;

(2) introducing the constituent chemical components of each reference sample into the mass spectrometer, under dynamic flow conditions;

(3) obtaining for each reference sample a series of time resolved mass chromatograms;

(4) calibrating the mass chromatograms to correct retention times;

(5) selecting a series of corrected retention time windows;

(6) selecting within each retention time window a series of molecular and/or fragment ions, said ions being representative of characteristic compounds or compound classes expected within the retention time window;

(7) recording the total amount of each characteristic compound or compound group selected in step d(6);

(8) forming the data from steps d(6) and d(7) into a Z-block matrix;

(9) forming the property data selected in (a) for reference samples selected in (b) into a Y-block matrix;

(10) analyzing the data from steps d(8) and d(9) by multivariate correlation techniques including Partial Least Squares, Principal Component Regression, or Ridge Regression to produce a series of coefficients;

(e) subjecting at least one unknown sample of at least one of lubricating oil, feed, distillate and raffinate to steps d(l) top d(3) in the same manner as the reference sample to produce a series of time resolved mass chromatograms;

(f) repeating steps d(4) and d(8) for each mass chromatogram from step (e);

(g) multiplying the matrix from step (f) by the coefficients from step d(10) to produce a predicted value for the property or properties ofthe at least one lubricating oil, and/or at least one feed, distillate and raffinate sample or samples; and

(h) using the predicted values ofthe property or properties ofthe lubricating oil and/or at least one ofthe feed, distillate and raffinate sample or samples to control operation of at least one ofthe distillation unit, extraction unit and dewaxing unit.

Another embodiment ofthe invention relates to a method for controlling or monitoring chemical or refinery processes which utilize feedstocks and/or produce products having boiling points greater than about 350°C which comprises:

(a) obtaining at least one sample ofa refinery or chemical feedstock or product;

(b) selecting at least one physical, chemical, perceptual or performance property of at least one refinery or chemical process feedstock or product;

(c) selecting reference samples, said reference samples containing characteristic compound types present in the at least one refinery or chemical process feedstock or product and which have known values for the property or properties selected in step (b);

(d) producing a training set by the steps of:

(1) injecting each reference sample into a gas chromatograph which is interfaced to a mass spectrometer thereby causing at least a partial separation ofthe hydrocarbon mixture into constituent chemical components;

(2) introducing the constituent chemical components of each reference sample into the mass spectrometer, under dynamic flow conditions.

(3) obtaining for each reference sample a series of time resolved mass chromatograms;

(4) calibrating the mass chromatograms to correct retention times;

(5) selecting a series of corrected retention time windows;

(6) selecting within each retention time window a series of molecular and/or fragment ions, said ions being representative of characteristic compounds or compound classes expected within the retention time window;

(7) recording the total amount of each characteristic compound or compound group selected in step d(6);

(8) forming the data from steps d(6) and d(7) into a X-block matrix;

(9) forming the property data selected in (a) for reference samples selected in (b) into a Y-block matrix;

( 10) analyzing the data from steps d(8) and d(9) by multivariate correlation techniques including Partial Least Squares, Principal Component Regression, or Ridge Regression to produce a series of coefficients;

(e) subjecting at least one unknown refinery or chemical process feedstock or process sample to steps d( 1 ) to d(3) in the same manner as the reference samples to produce a series of time resolved mass chromatograms;

(f) repeating steps d(4) and d(8) for each mass chromatogram from step (e);

(g) multiplying the matrix from step (f) by the coefficients from step d(10) to produce a predicted value ofthe property or properties for the refinery or chemical process feedstocks or products sample or samples; and

(h) using the predicted values ofthe property or properties ofthe refinery or chemical feedstocks, intermediate or products sample or samples to control the refinery or chemical process.

The gas chromatography/mass spectrometry (GC/MS) method described above can be used to rapidly predict a wide range of perceptual, performance, chemical and/or physical properties of complex mixtures such as intermediate streams in the lubes manufacturing process and lubricating oil products. Such properties include distillation characteristics, pour point, density, aniline point, feedstock quality, cloud point, haze, viscosity and the like as well as specific chemical constituents. The multivariate correlation methods can also treat the collinear data generated by the GC/MS analyses.

BRIEF DESCRIPTION OF THE DRAWING

Figure 1 is a schematic flow diagram ofa manufacturing process for a lube oil.

DETAILED DESCRIPTION OF THE INVENTION

The typical lubricating oil manufacturing process involves a distillation unit, an extraction unit, a dewaxing unit and optionally, a hydrofining unit. The lubricating oil products are commonly used as base stocks for producing finished oils or may be specialty products such as transformer oils and agricultural oils.

Figure 1 is a schematic flow diagram showing an on-line manufacturing process. Feed stocks 10 are complex hydrocarbon mixtures such as crudes or heavy distillate streams. The feedstock is fed to distillation unit 20 through line 12. Feedstock may be sampled through sampling port 14 which is connected to sampling line 16 interrupted by valve 18.

Distillation unit 20 is typically a pipestill which distills the feed stock into a plurality of distillation cuts. For purposes of simplicity, these distillation cuts are shown exiting unit 20 as line 22 which represents a plurality of lines where n is the number of distinct distillation cuts. Each ofthe lines 22n may be sampled through sampling ports 24n which are connected to sampling lines 26n interrupted by valves 28n.

The distillate cuts are fed to extraction unit 30 where they are extracted using solvents such as phenol, N-methylpyrrolidone and the like. The extraction process results in raffinates and bottoms. Again for purposes of simplicity, these raffinates are shown exiting the extraction unit 30 as a single line 32n which represents a plurality of lines where n is the number of different raffinate extracts. Each ofthe lines 32n may be sampled through sampling ports 34n which are connected to sampling lines 36n interrupted by valves 38n. The raffinate extracts are usually stripped of solvent in a stripping unit (not shown) prior to entering the dewaxing unit.

In the dewaxing unit 40, wax is removed by dewaxing aids such as methyl ethyl ketone, propane and the like. As in the previous units, for purposes of simplicity, the dewaxed raffinates are shown exiting the dewaxing unit 40 as a single line 42n where n is the number of dewaxed raffinates. Each of lines 42n may be sampled

through sampling ports 44n which are connected to sampling lines 46n interrupted by valves 48n.

The dewaxed raffinates exiting unit 40 through lines 42n may be used as lubricating oils (following removal of dewaxing aid). Typical examples of such lube oils are known as light neutrals, heavy neutrals, bright stocks and the like. These lube oils may be sampled for product quality through sampling ports 44n connected to sampling lines 46n interrupted by valves 48n. These lube oils may optionally be subjected to a hydrofinishing step in a hydrofiner unit 50. Hydrofiners use catalysts and conditions well known in the art. The hydrofinished products exit hydrofiner 50 through lines 52m where m represents the number of lube oils subjected to hydrofinishing. The hydro- finished oils may be sampled through sampling ports 54m connected to sampling lines 56m interrupted by valves 58m.

Each of lines 16, 26n, 36n, 46n and 56m are connected to sampling manifold 60. Sampling manifold 60 also includes an optional provision for at-line operation wherein a remote location 70 is connected to the sampling manifold 60 through line 62 interrupted by valve 66 and sampling port 64. Sampling manifold 60 is a central location where all samples to be analyzed are gathered prior to GC/MS analysis. Manifold 60 can be purged by sample to be analyzed to remove contaminants and purged material recycled through line 72 interrupted by valve 74.

Sample to be analyzed is fed through line 76 to sample injection valve 80 Injection valve 80 can likewise be purged by sample to be analyzed through line 82 interrupted by valve 84. Once sample manifold 60 and sample injection valve 80 are purged, sample to be analyzed is injected into GC/MS analyzer. Samples from off-line operation can be directly injected through valve 80. Off-line samples are those collected at remote locations and brought to a central facility for analysis. The raw data generated by GC/MS analyzer 90 is fed to computer 100. Spent sample and purging materials are sent to recycle through line 92 interrupted by valve 94. Computer 100 mathematically treats raw GC/MS data. Output from computer 100 is then fed as an electronic signal through line 102 to control computer 1 10. Control computer 1 10 is connected through line 112 to units 20, 30, 40 and 50 and controls operating conditions within said units 20, 30, 40 and 50. The operating conditions in turn controls the quality of lube oil product exiting unit 40 and/or 50.

The operation ofthe GC/MS analyzer 90 and computer 100 is described in further detail as follows. The feedstock, distillate cuts and lubricating oil products are all complex hydrocarbon mixtures involving thousands of individual chemical species. The use of GC/MS to analyze such complex mixtures for chemical and physical properties involves the generation of large amounts of collinear data. Multiple regression analysis may be employed for treating normal linear data. However, this type of analysis cannot be used for collinear data.

The process according to the invention involves a means for predicting chemical, performance, perceptual and physical properties of feedstock, distillates, raffinates and lubricating oils by quantitative identification of components using a combination of retention times from a GC analysis coupled with target fragment and/or molecular ions produced by the MS. The MS information is compared against a set of known properties from reference samples which form a training set. By mathematically comparing the experimental data with that ofthe training set, one may predict the desired properties of other feedstocks, distillates, raffinates and lubricating oils.

GC/MS utilizes a gas chromatograph interfaced with a mass spectro¬ meter. While a chromatographic method such as supercritical fluid chromatography, liquid chromatography or size exclusion chromatography may be used to separate the mixture into components or mixtures of components, gas chromatography, especially capillary gas chromatography is the preferred means for interfacing with a mass spectrometer. Both GC and MS use computer software for instrument control, data acquisition and data reduction. The computer platform should be capable of acquiring at least 2000 mass spectra in about 7 minutes.

The sample mixture to be analyzed is first injected into a GC where the mixture components are separated as a function of retention time, often on the basis of boiling points. Only partial chromatographic resolution of mixture components is necessary. The GC oven temperature is usually programmed for samples with a wide boiling range. Separated components may also be identified by a detector such as a flame ionization detector, atomic emission detector, thermal conductivity detector or electron capture detector.

The separated or partially separated components are then transferred to the mass spectrometer under dynamic flow conditions. Since a GC operates under atmospheric pressure and a MS under vacuum condition (about lO'-^kPa), the

instrument interface requires a coupling device such as a molecular separator (e.g., jet, membrane, etc.), open split coupler or capillary direct interface to efficiently transfer sample while minimizing carrier gas effects.

Depending on the nature ofthe sample, the mixture may be introduced directly into a MS using a direct insertion probe without a prior GC separation step. Other thermal separation techniques not involving a GC may be used to introduce the sample into the mass spectrometer.

In the MS, sample molecules are bombarded with high energy electrons thereby creating molecular ions which fragment in a pattern characteristic ofthe molecular species involved. A continuous series of mass spectra are obtained over a scan range of at least 10 to at least 800 daltons. The mass spectral data may also be acquired under selected ion monitoring (SIM) mode. In the selected ion mode, care must be taken to select ions representative ofthe components of interest and to operate under repeatable conditions. A variety of MS instruments may be used including low resolution, high resolution, MS/MS (hybrid, triple quadrupole, etc.), ion cyclotron resonance and time of flight. Any ionization technique may be used, such as electron ionization, chemical ionization, multiphoton ionization, field desorption, field ionization, etc., provided that the technique provides either molecular or fragment ions which are suitable for use in the analysis procedure.

The results of sample analysis are a series of I mass spectra. The mass spectra are divided into n time intervals where n is an integer from 1 to I. At least one diagnostic ion is chosen from each of m time intervals where m is an integer from 1 to n. The term "diagnostic ion" refers to an ion which is representative ofa compound, a chemical class or a performance, perceptual or physical property correlated thereto. Regardless of whether mass spectra are obtained in the scan or selected ion monitoring mode, it is important that the mass spectra be obtained under repeatable conditions.

If the mass spectral data are acquired in the scan mode, the mass range covered during acquisition should be sufficient to provide acquisition of all ofthe ions which could be used as diagnostic ions during mathematical treatment of each mass spectral scan. If the mass spectral data are acquired in the selected ion monitoring mode, then care must be taken that the ions selected for monitoring are suitable for use in measuring the components of interest.

The sample mass spectral data are then compared to mass spectral data from a series of reference samples with known performance, perceptual, physical and/or chemical properties. In order to compare reference mass spectral data with sample mass spectral data, it may be desirable to time align the sample data to help ensure the integrity ofthe comparison. There are commercially available computer programs for such data alignment, for example, Hewlett-Packard GC/MS software G 1034C version C.01.05.

The reference mass spectral data, and associated properties data, are arranged in matrix form for mathematical treatment as described below. In the case of chemical composition information, one matrix is formed of reference sample ion intensities at given masses and the other matrix contains known ion intensities for molecular fragment ions of known components. The training set for chemical composi¬ tion data is thus made up of mass spectral data for different components characteristic of compounds or molecular series expected to be found in the sample mixtures. Similar training sets can be formed for other chemical or perceptual or performance or physical properties of interest. These training sets form one block or matrix of data (Y-block or properties matrix). The actual sample mass spectral data (which may have been time aligned) form the other block (X-block) or matrix of data. These two matrices are subjected to mathematical treatments known as Partial Least Squares (PLS), or Principal Component Regression (PCR), or Ridge Regression (RR) to obtain a mathematically describable relationship between the properties data and mass spectral data, known as a model. Coefficients provided by this model are mathematically combined with the suitably treated mass spectral data from samples with unknown desired properties to:

a) predict desired properties b) assess the suitability ofthe model for such predictions, and c) diagnose the stability and general correctness ofthe process that yielded the mass spectral data

PLS/PCPJRR are described in the literature, e.g., Wold S., A. Ruhe, H. Wold, and W. J. Dunn, "The Collinearity Problem in Linear Regression. The Partial Least Squares (PLS) Approach to Generalized Inverses", SIAM J. Sci. Stat. Comput, 1984 5(3), 735-743, or Geladi P., and B. R. Kowalki, "Partial Least Squares Regression: A Tutorial", Anal. Chem. Acta, 1986, 185, 1-17, or Hόkuldsson A., "PLS Regression Methods", J. Chemometrics, 1988, 2, 21 1-228, or in many other articles in journals such as the Journal of Chemometrics or Intelligent Laboratory Systems; Frank,

I., and J. Friedman, "A Statistical View of Some Chemometrics Regression Tools", Technometrics, 1993, Vol. 35, No. 2; Jackson, J. E., "A User's Guide to Principal Components", Wiley-Interscience, New York, 1991; Montogomery, D.C. and E. A. Peck, "Introduction To Linear Regression Analysis", Wiley-Interscience, New York, 1990; and Martens, H., and T. Naes, "Multivariable Calibration", Wiley-Interscience, New York, 1989.

When dealing with a complex mixture, it is necessary to select appropriate masses or groups of masses at specific retention times for a particular compound or classes of compounds. The selection of such masses is the basis for a set a rules which then forms the data for the training set. There are no set procedures for such a selection process. The researcher must select appropriate masses for compounds of interest. For example, feed stocks and lube oils contain a wide range of compound types such as paraffins, cycloparaffins, aromatics, and olefins. It is known that paraffinic hydrocarbons yield fragment ions at masses 43, 57, 71, 85,... daltons, and these masses may be used as diagnostic of this class of compounds. Moreover, when coupled with retention time data, it is possible to identify concentrations of specific compounds within this class of compounds. In a similar manner, training sets for other chemical, performance, perceptual or physical properties may be developed by correlating compositional data with other properties of interest, e.g., distillation characteristics, viscosities and viscosity index, volatility, refractive index and the like. The result of a mathematical treatment such as PLS/PCR/RR ofthe training set is a set of coefficients for the properties of interest.

These coefficients are then multiplied by the data matrix for the sample. The result is a prediction ofthe desired property or properties which information can be used to control operating conditions in the distillation unit, extraction unit, dewaxing unit and/or hydrofiner as well as control lube oil quality. Moreover, variances in properties serve to promptly alert operators of upsets/changes in operating conditions which could influence product quality. The method ofthe invention is further illustrated by the following examples.

EXAMPLE 1

The method for predicting the physical or chemical properties ofa complex hydrocarbon mixture is demonstrated in this example using density at 15°C as the specific property for purposes of illustration. The method is generally applicable to a

range of other physical properties as well as performance or perceptual or chemical properties of such mixtures.

The initial consideration is to establish a set of standard GC/MS operating parameters so that the GC/MS analytical data used for predicting properties is obtained under consistent operating conditions. The GC/MS instrument used in this example is a Hewlett-Packard 5972 Mass Selective Detector interfaced to a Hewlett Packard 5890 Series II Gas Chromatograph fitted for use with microbore columns.

The GC/MS operating conditions are summarized in Table 1.

TABLE 1

GC Conditions

Column Phenyl Silicone (such as HP-5) 10m x 0.1 mm, 17 micron film thickness

Temperature Program

Initial Temperature (°C) 180

Initial Time (minutes) 0

Program Rate (°C/min) 15

Final Temperature (°C) 310

Final Time (minutes) 5.33

Pressure Program

Initial Pressure (psi) 30

Initial Time (minutes) 0

Program Rate (psi/minute) 4

Final Pressure (psi) 80

Final Time (minutes) 10

Carrier Gas Helium

Linear Velocity 25.6

Injection Port Temperature (°C) 300

Injection Volume μL 0.5

Split Ratio 500:1

Column Head Press, kPa Approx. 260

Interface Temperature (°C) 310

Mass Spectrometer Conditions

Ionization Mode Electron Ionization, 70 eV nominal

Cycle Time (minutes) 0.003

In order to predict properties (density in this example) of an unknown hydrocarbon mixture, it is first necessary to select reference samples having known values ofthe property or properties of interest. A series of twenty-seven (27) samples of 150N grade waxy raffinates from various crude oils were prepared and used in this example. These reference samples were used to form both training and test sets as described below.

A data treatment method should be selected prior to obtaining raw GC/MS data. Two types of data treatments which may be used are either Chemist's Rules or Hydrocarbon Compound Type Analysis as described, for example, in Robinson, C.J., "Low Resolution Mass Spectrometric Determination of Aromatics and Saturates in Petroleum Fractions", Analytical Chemistry, 1971, 43(1 1), pp. 1425-1434.

Chemist's Rules involve two separate sections: (1) a calibration section to correct retention times, i.e., the time between zero and the time when a given peak occurs; and (2) the actual Rules which are based on a selected series of masses corresponding to prominent compounds or molecular series expected for the type of hydrocarbon mixture under investigation. These compounds or compound types are selected on the basis that they have prominent molecular and/or fragment ions unique to that compound or molecular series. A portion ofthe Chemist's Rules are shown in Table 2. A full set of Chemist's Rules are shown in its entirety following Example 4.

TABLE2 COMPLETECHEMIST'SRULESFORLUBES

Retention Time*- ¹

Rule ³ Material ⁰ Masses ^* - ^* Starting Ending

1 nC16 43 57 71 85 99 113 1.00 1.89

2 1/2 ring 69 83 97 109 123 137 1.00 2.30

3 3/4 ring 149 163 177 189 203 217 1.00 2.30

4 4/5 ring 229 243 257 269 283 297 1.00 2.30

5 6 ring 309 223 337 1.00 2.30

6 -6 1 105 119 133 147 161 1.00 2.30

7 -6.1 92 106 120 134 148 162 1.00 2.30

8 -8/-10 115 117 129 131 143 145 1.00 2.30

9 -12 128 141 142 155 156 169 1.00 2.30

10 -14/-16 151 153 165 167 179 181 1.00 2.30

11 -18 178 191 192 205 206 219 1.00 2.30

12 -20 202 215 226 239 228 241 1.00 2.30

13 nC17 43 57 71 85 99 113 1.89 1.98

13 nC17 43 .57 71 85 99 113 1.89 1.98

14 isoPara 43 57 71 85 99 113 1.98 2.30

15 nC18 43 57 71 85 99 113 2.30 2.40

16 isoPara 43 57 71 85 99 113 1.980 2.300

17 1/2 ring 69 83 97 109 123 137 2.400 3.220

18 3/4 ring 149 163 177 189 203 217 2.400 3.220

19 4/5 ring 229 243 257 269 283 297 2.400 3.220

172 -8/- 10 1 15 117 129 131 143 145 12.07 14.00

173 -12 128 141 142 155 156 169 12.07 14.00

174 -14/-16 151 153 165 167 179 181 12.07 14.00

175 -18 178 191 192 205 206 219 12.07 14.00

176 -20 202 215 226 239 228 241 12.07 14.00

177 nC 9 43 57 71 85 99 113 12.83 12.87

178 isoPara 43 57 71 85 99 113 12.88 14.00

a) Rule number, integer index

b) Compound or group of compound rule applies to: 1/2 ring 1/2 ring cycloparaffins

3/4 ring 3/4 ring cycloparaffins

4/5 ring 4/5 ring cycloparaffins

6 ring 6 ring cycloparaffins

-6 _n H2 _n -6 alkylated benzenes

-6.1 C _n H2n-6 linear alkkylated benzenes

-8/- 10 _n H2 _n -8 alkylated indanes, C _n H2 _n -lθ alkylated indenes

- 12 _n H2 _n - 12 alkylated naphthalenes

-14/16 C _n H2n- 14 alkylated acenaphthenes/C _n H2 _n .16 alkylated acenaphthalenes

- 18 C _n H2 _n - 18 alkylated phenanthrenes/anthracenes

-20 C _n H2 _n _20 alkylated naphthenophenanthrenes

c) Masses used in Rule [up to n may be specified, where n is an integer which is equial to the number of masses scanned during the time interval (d)].

d) Retention time for both starting and ending expected retention times based on historical averages in minutes.

A reference retention time is then determined for each mass spectral ion grouping selected for use in the Chemist's Rules for each ofthe selected molecular types or molecules identified in Table 2. Such corrections are necessary due to slight shifts in retention times which may result from column degradation, column head pressure fluctuations, changes in column carrier gas linear velocity, or minor fluctuations in the GC column oven temperatures or other causes. The calibration step generates a series of correction factors for the entire GC/MS data file. There are commercially available programs which will perform retention time corrections. The results of applying such corrections are shown in Table 3.

TABLE 3

REFERENCE CALIBRATION

MASS ^a TIME ^b TYPE ^C LIMIT ^d TIME ^e CORRCTION ^f

268 2.800 P 0.15 2.794 -0.006

282 3.276 P 0.15 3.272 -0.004

366 6.260 P 0.15 6.266 0.006

422 7.953 P 0.15 7.953 0.000

57 10.556 P 0.15 10.591 0.035

a) Mass or compound selected for the calibration

b) Expected occurrence time, typically based on average of several analyses

c) P=Peak or maximum occurrence, F=First occurrence ofthe material

d) Range (± minutes) for reference material

f) Correction to be applied between reference materials (column a). Correction for first material is from initial time to calibration time; correction for second material is between first and second reference materials; and last correction is applied to end of data acquisition.

Once the correction coefficients are determined, the actual Rules are then determined. In the case of density preduction, a total of 178 Rules is used based on compound or compound series identification. For each Rule, a set of characteristic mass numbers are determined. These characteristic mass numbers can range from 1 to n, where n is an integer representing the entire mass range scanned or the number of selected ions being monitored. In this case, six characteristic mass numbers are illustrated. The ion intensities ofthe masses for each Rule are summed within the upper and lower retention time limits for that rule. The results are shown for a sampling ofthe 178 Rules in Table 4 for this demonstration analysis. A full set of rules is shown in its entirety following Example 4.

TABLE 4

CHEMIST'S RULES FOR LUBES

Total Raw Abundance (TIC): 770247450

Chemist Rule: 398341548 -51.72%

Air Leakage: 247241 -0.03%

Average Scan Rate (Min/Max): 292 (292/293)

Number of Records: 2864

Rule Compound Masses Start End ⁶ CStart Con ^*8 CEnd ^h Corr Abundance

1 nC16 43 57 71 85 99 1 13 1.000 1.890 0.998 -0.002 1.886 -0.004 1 1823 0.00%

2 1/2 ring 69 83 97 109 123 137 1.000 2.300 0.998 -0.002 20.295 -0.005 32274 0.01%

3 3/4 ring 149 163 177 189 203 217 1.000 2.300 0.998 -0.002 2.295 -0.0052 0 0.00%

4 4/5 ring 229 243 257 269 283 297 1.000 2.300 0.998 -0.002 2.295 -0.005 0 0.00%

5 6 ring 309 223 337 1.000 2.300 0.998 -0.002 2.295 -0.005 0 0.00%

6 -6 91 105 1 19 133 147 161 1.000 2.300 0.998 -0.002 2.295 -0.005 0 0.00%

7 -6.1 92 106 120 134 148 162 1.000 2.300 0.998 -0.002 2.295 -0.005 0 0.00%

8 -8/- 10 1 15 1 17 129 131 143 145 1.000 2.300 0.998 -0.002 2.295 -0.005 0 0.00%

9 -12 128 141 142 155 156 169 1.000 2.300 0.998 -0.002 2.295 -0.005 0 0.00%

10 -14/-16 151 153 165 167 179 181 1.000 2.300 0.998 -0.002 2.295 -0.005 0 0.00%

1 1 -18 178 191 192 205 206 219 1.000 2.300 0.998 -0.002 2.295 -0.005 0 0.00%

12 -20 202 215 226 239 228 241 1.000 2.300 0.998 -0.002 2.295 -0.005 0 0.00%

13 nC 17 43 57 71 85 99 1 13 1.890 1.980 1.886 . -0.004 1.976 -0.004 83071 0.02%

14 isoPara 43 57 71 85 99 113 1.980 2.300 1.976 -0.004 2.295 -0.005 163356 0.04%

15 nC 18 43 57 71 85 99 1 13 2.300 2.400 2.295 -0.005 2.395 -0.005 417625 0.1 1%

16 isoPara 43 57 71 85 99 113 2.400 3.220 2.395 -0.005 3.216 -0.004 3447651 0.87%

17 1/2 ring 69 83 97 109 123 137 2.400 3.220 2.395 -0.005 3.216 -0.004 1770916 0.45%

18 3/4 ring 149 163 177 189 203 217 2.400 3.220 2.395 -0.005 3.216 -0.004 1689 0.00%

19 4/5 ring 229 243 257 269 283 297 2.400 3.220 2.395 -0.005 3.216 -0.004 0 0.00%

•

172 -8/- 10 115 1 17 129 131 143 145 12.070 14.000 12.105 0.035 14.035 0.035 0 0.00%

173 -12 128 141 142 155 156 169 12.070 14.000 12.105 0.035 14.035 0.035 0 0.00%

174 -14/-16 151 153 165 167 179 181 12.070 14.000 12.105 0.035 14.035 0.035 0 0.00%

175 -18 178 191 192 205 206 219 12.070 14.000 12.105 0.035 14.035 0.035 0 0.00%

176 -20 202 215 226 239 228 241 12.070 14.000 12.105 0.035 14.035 0.035 0 0.00%

177 nC39 43 57 71 85 99 1 13 12.830 12.870 12.865 0.035 12.905 0.035 791 1 0.00%

178 isoPara 43 57 71 85 99 1 13 12.880 14.000 12.915 0.035 14.035 0.035 106764 0.03%

Sum = 398341548 100.00%

a) Rule number, integer index

b) Compound or group of compound mle applies to: 1/2 ring 1/2 ring cycloparafffins

3/4 ring 3/4 ring cycloparaffins

4/5 ring 4/5 ring cycloparaffins

6 ring 6 ring cycloparaffins

-6 C _n H2n-6 alkylated benzenes -6. C _n H2 _n -6 linear alkylated benzenes

-8/- 10 C _n H2n-8 alkylated indanes, C _n H2 _n -10 alkylated indenes

- 12 C _n H2 _n - 12 alkylated naphthalenes

-14/16 C _n H2n- 14 alkylated acenaphthenes/C _n H2 _n .16 alkylated acenaphthalenes

- 18 _n H2n- 18 alkylated phenanthrenes/anthracenes

-20 _n H2n-20 alkylated naphthenophenanthrenes

c) Masses used in Rule [up to n may be specified, where n is an integer which is equal to the number of masses scanned during the time interval (d to e) either in full scan mode or selected ion monitoring mode].

d) Retention time for both starting and ending expected retention times based on historical averages in minutes.

e) end retention time in minutes I

f) corrected start retention time

g) correction = difference between start and cstart (in minutes)

h) corrected end time

i) correction = difference between end and cend (in minutes) j) Abundance, both as total sum and as normalized percentage based on Chemist's Rules

Total Raw Abundance (TIC): total area observed in the GC/MS analysis.

Chemist Rule: total area found using the Chemist's Rules; based on experience, should be greater than 30% of total raw abundance.

Air Leakage: total ionization due to air (m/z 28, 32, 40, 44) useful diagnostic for instrumentation problems.

Average Scan Rate (Min Max): shows the minimum, average and maximum scan rates during the GC/MS analysis and is a useful diagnostic to identify instrumental problems.

Number of records: is the number of mass spectral scans acquired during the analysis.

The analysis summarized in Table 4 is done for each reference sample. The results from these respective analyses form a training set which is subjected to mathematical treatment. The goal is develop a model that can be used to predict the unknown properties of future samples using their mass spectral data only. The mathe¬ matical treatments are described by multivariate correlation techniques such as Projection to Latent Structures (PLS) or otherwise known as Partial Least Squares (PLS), Principal Component Regression (PCR), and Ridge Regression (RR). These techniques are superior to ordinary multiple linear regression in their ability to treat collinearity amongst variables in the X-block or GC/MS data matrix (and Y-block or properties matrix for PLS), and in their ability to handle the quantity of data generated by the Chemist's Rules. Ordinary Multiple Linear Regression cannot be used to treat collinear variables.

PLS/PCR/RR are numerical analysis techniques for detecting and formulating a mathematical structure (model) within a data set comprising observations associated with multiple objects. Each object has associated without observations for multiple variables, the latter being common to all objects. These multiple variables are assigned into two categories, known as X-block and Y-block (GC/MS data in this case). Observations associated with all variables in the X-block are realized from a common process. Observations associated with variables in the Y-block (known properties in this

case) are realized from processes that may be different for each variable. The data set used to construct this mathematical model is referred to as the model calibration data set.

The common use of PLS/PCR RR is to apply the model developed from the calibration data set to X-block observations realized for new objects (not in the calibration data set) to predict values for the corresponding variables in the Y-block for these new objects, without having to execute the Y-block processes used in the calibration data set. Using diagnostics that are simultaneously generated by the PLS/PCR/RR model, assessment of whether the new objects can be adequately described by the model, and whether the model is used in an extrapolation mode versus interpolation mode can be performed.

PLS/PCR addresses the collinearity features in the X-block and Y-block, by suitably reducing the dimensionality in both X- and Y-blocks (for PLS), and X-block only (for PCR) to form the model. Collinearity is a term referring to the existence of relationships between variables within the block itself. In the PLS modeling algorithm a number of independent dimensions in the X- and Y- blocks are identified by forming pseudo-variables known as principal components or latent vectors through different sets of linear combinations of original variables in each block. Each set of such combinations constitutes an independent dimension. It comprises a set of coefficients that each value associated with each variable in the block is to be weighted by to arrive at the new value for this dimension. The values for the new, reduced dimensions in the Y-block are regressed onto their counterparts in the new, reduced dimensions ofthe X-block to arrive at the most parsimonious dimension size (number of latent vectors) and their associated weights, with the final goal of one linear equation generated to permit predic¬ tion of Y-block variables using X-block variables. The number of dimensions used to construct the model is determined through optimization of a criterion known as PRESS (Prediction Error Sum of Squares), cumulated by a Cross Validation (CV) technique using the training data set, and, following the general model parsimony principle.

For PCR, the number of independent dimensions in the X-block are first selected and identified in a similar fashion as in PLS by forming principal components. Then, for each variable in the Y-block, a model is obtained by performing ordinary multiple linear regression using the Principal Components as "Prediction Variables".

For Ridge Regression, the collinearity problem is dealt with in a different manner than PLS/PCR. Here a diagonal matrix known as the Lambda Matrix is added to the Covariance Matrix ofthe X-block with the net effect of stabilizing the numerical computation needed to obtain the model coefficients. The selection of Lambda values is through optimization of PRESS criterion using cross validation ofthe training set.

Thus, the Chemist's Rule data for the various reference samples derived from GC/MS analysis form the X-block variables. PLS/PCR/RR treatment may require preliminary reorganization ofthe X-block data, such as transposition and removal of redundant data and constants or mathematical transformations. The Y-block variables are the property (or properties) to be predicted, and may also require mathematical transformations such as logarithmic or geometric, as well as reorganization. The data blocks may be represented by:

X-BLOCK MATRIX [Chemist's Rules (n samples x 178 columns)]

^x u ^X L2 ^X l,3 ^x l,176 ^x l,177 ^x l,178 ^x 2, l ^x 2,2 ^X 2,3 ^x 2, 176 ^x 2,177 ^x 2, 178

^X 3,l ^x 3.2 ^x 3.3 ^x 3, 176 ^x 3,177 ^x 3,178

X n, l -*n,2 X n,j ^x n, 176 ^x n, 177 ^x n, 178

Y-BLOCK VECTOR [Measured property or properties (n samples)]

The Y-block may be a single observation per set of Chemist's Rules as shown above, or it may be a n x m matrix of observations where there are m different properties to be predicted.

The results of PLS treatment ofthe training set data are a series of coefficients. Raw GC/MS data from an unknown sample (or samples) are then treated by the Chemist's Rules first to correct the retention times and then to form the ion summations. Each value for the Chemist's Rule ion summation result is then multiplied by the training set coefficients and summed to generate the prediction ofthe desired property. Table 5 illustrates the quality ofthe predicted density values for both the training set and the unknown test set for density at 15°C.

TABLE 5 Predicted vs. Measured Waxy Raffinate Density Values @ 15°C (g/ml)

Test Set

24 0.8695 0.8691

25 0.8664 0.8644

26 0.8665 0.8645

27 0.8768 0.8758 measured by ASTM D 4052-91

EXAMPLE 2

The procedure of Example 1 was repeated for predicting refractive index @ 75°C for the suite of 150N grade waxy raffinates. The same 22 samples were used for the training set, while the remaining five samples were used as a test set. The results for the refractive index at 75°C are summarized in Table 6.

TABLE 6 Predicted vs. Measured Refractive Index @ 75°C

Measured* Predicted

Training Set

1 1.4441 1.4434

2 1.4505 1.4504

3 1.4534 1.4527

4 1.4509 1.4526

5 1.4540 1.4551

6 1.4509 1.4507

7 1.4550 1.4540

8 1.4504 1.4499

9 1.4495 1.4500

10 1.4523 1.4514

11 1.4525 1.4532

12 1.4573 1.4577

13 1.4628 1.4626

14 1.4506 1.4500

15 1.4542 1.4535

16 1.4528 1.4538

17 1.4575 1.4571

18 1.4581 1.4575

19 1.4505 1.4519

20 1.4512 1.4519

21 1.4616 1.4609

22 1.4576 1.4582

Test Set

23 1.4497 1.4503

24 1.4546 1.4546

25 1.4525 1.4522

26 1.4530 1.4526

27 1.4582 1.4579

^♦ measured by ASTM D 1218-92

EXAMPLE 3

The procedure of Example 1 was repeated for predicting viscosity at 100°C for 150N grade waxy raffinates. The same 22 samples were used for the training set, while the remaining five samples were used as a test set. The results for density prediction are summarized in Table 7.

TABLE 7 Predicted vs. Measured Viscosity @ 100°C (cSt)

Measured* Predicted

Training Set

1 5.38 5.37

2 4.72 4.74

3 4.79 4.79

4 4.68 4.74

5 4.74 4.79

6 4.48 4.48

7 4.49 4.42

8 4.35 4.27

9 4.38 4.34

10 4.44 4.38

1 1 4.41 4.53

12 4.61 4.66

13 4.76 4.84

14 4.49 4.45

15 4.59 4.56

16 4.84 4.88

17 4.96 5.00

18 4.74 4.62

19 4.16 4.39

20 4.91 4.88

21 5.19 5.14

Test Set

22 5.07 5.07

23 4.35 4.45

24 4.67 4.51

25 4.39 4.41

26 5.00 4.90

27 4.81 4.79

"measured by ASTM D 445-88

EXAMPLE 4

The procedure of Example 1 was repeated for predicting weight percent wax content for 150N grade waxy raffinates. The same 22 samples were used for the training set, while the remaining five samples were used as a test set. The results for density prediction are summarized in Table 8.

TABLE 8 Predicted vs. Measured Wax Content (Wt%)

Measured* Predicted

Training Set

1 21.8 22.0

2 25.7 23.5

-» J 20.0 21.5

4 20.6 20.0

5 19.1 17.8

6 29.6 29.5

7 17.5 18.6

8 20.0 21.4

9 20.8 19.9

10 19.4 18.8

1 1 18.8 19.8

12 3.6 3.6

13 2.4 0.9

14 18.4 20.8

15 16.9 18.0

16 16.2 16.5

17 14.6 14.4

18 6.7 7.5

19 20.2 17.4

20 21.2 21.1

Test Set

21 10.4 10.4

22 1 1.6 12.3

23 23.5 22.5

24 7.6 9.4

25 18.1 17.5

26 20.4 20.2

27 8.6 8.4

^♦ measured by ASTM D 3235-88

Other properties of various grades of lubricating intermediate streams or finished products, such as, cloud point, flash point, viscosity index, pour point, basic nitrogen content, distillation and volatility characteristics, viscosity at 40°C, aniline point, sulfur content, etc., could be predicted using the method according to the invention.

The subject method can also be applied for predicting properties of other types of complex hydrocarbon mixtures in similar boiling ranges, such as catalytic cracker feedstock quality, feed to extraction or dewaxing units, feedstocks to distillation or stripping towers, and to blending considerations.

COMPLETE CHEMIST'S RULES FOR LUBES

Retention Time

Rule ^a Material"- ⁵ Masses ⁰ Starting Ending

1 nC16 43 57 71 85 99 1 13 1.00 1.89

1/2 ring 69 83 97 109 123 137 1.00 2.30

3/4 ring 149 163 177 189 203 217 1.00 2.30

4/5 ring 229 243 257 269 283 297 1.00 2.30

6 ring 309 223 337 1.00 2.30

-6 91 105 1 19 133 147 161 1.00 2.30

-6.1 92 106 120 134 148 162 1.00 2.30

-8/- 10 1 15 1 17 129 131 143 145 1.00 2.30

-12 128 141 142 155 156 169 1.00 2.30

10 -14/- 16 151 153 165 167 179 181 1.00 2.30

1 1 -18 178 191 192 205 206 219 1.00 2.30

12 -20 202 215 226 239 228 241 1.00 2.30

13 nC17 43 57 71 85 99 1 13 1.89 1.98

14 isoPara 43 57 71 85 99 1 13 1.98 2.30

15 nC18 43 57 71 85 99 113 2.30 2.40

16 isoPara 43 57 71 85 99 1 13 2.40 3.22

17 1/2 ring 69 83 97 109 123 137 2.40 3.22

18 3/4 ring 149 163 177 189 203 217 2.40 3.22

19 4/5 ring 229 243 257 269 283 297 2.40 3.22 0 6 ring 309 223 337 2.40 3.22 1 -6 91 105 1 19 133 147 161 2.40 3.22

22 -6.1 92 106 120 134 148 162 2.40 3.22

23 -8/- 10 1 15 1 17 129 131 143 145 2.40 3.22

24 -12 128 141 142 155 156 169 2.40 3.22

25 -14/-16 151 153 165 167 179 181 2.40 3.22

26 -18 178 191 192 205 206 219 2.40 3.22

27 nC 19 43 57 71 85 99 1 13 2.70 2.85

28 isoPara 43 57 71 85 99 1 13 2.85 3.22

29 nC20 43 57 71 85 99 1 13 3.22 3.34

30 isoPara 43 57 71 85 99 1 13 3.34 3.70

31 1/2 ring 69 83 97 109 123 137 3.34 4.20

32 3/4 ring 149 163 177 189 203 217 3.34 4.20

4/5 ring 229 243 257 269 283 297 3.34 4.20

34 6 ring 309 223 337 3.34 4.20

35 -6 91 105 1 19 133 147 161 3.34 4.20

36 -6.1 92 106 120 134 148 162 3.34 4.20

37 -8/- 10 1 15 1 17 129 131 143 145 3.34 4.20

38 -12 128 141 142 155 156 169 3.34 4.20

39 -14/-16 151 153 165 167 179 181 3.34 4.20

-18 178 191 192 205 206 219 3.34 4.20

-20 202 215 226 239 228 241 3.34 4.20 nC21 43 57 71 85 99 1 13 3.70 3.83 isoPara 43 57 71 85 99 1 13 3.84 4.20 nC22 43 57 71 85 99 1 13 4.20 4.33 isoPara 43 57 71 85 99 1 13 4.33 4.72

1/2 ring 69 83 97 109 123 137 4.33 5.20

3/4 ring 149 163 177 189 203 217 4.33 5.20

4/5 ring 229 243 257 269 283 297 4.33 5.20

6 ring 309 223 337 4.33 5.20

-6 91 105 1 19 133 147 161 4.33 5.20

-6.1 92 106 120 134 148 162 4.33 5.20

-8/- 10 1 15 1 17 129 131 143 145 4.33 5.20

-12 128 141 142 155 156 169 4.33 5.20

-14/-16 151 153 165 167 179 181 4.33 5.20

-18 178 191 192 205 206 219 4.33 5.20

-20 202 215 226 239 228 241 4.33 . 5.20 nC23 43 57 71 85 99 1 13 4.72 4.83 isoPara 43 57 71 85 99 1 13 4.83 5.20 nC24 43 57 71 85 99 1 13 5.20 5.37 isoPara 43 57 71 85 99 1 13 5.38 5.64

1/2 ring 69 83 97 109 123 137 5.38 6.15

3/4 ring 149 163 177 189 203 217 5.38 6.15

4/5 ring 229 243 257 269 283 297 5.38 6.15

6 ring 309 223 337 5.38 6.15

-6 91 105 1 19 133 147 161 5.38 6.15

-6.1 92 106 120 134 148 162 5.38 6.15

-8/- 10 1 15 1 17 129 131 143 145 5.38 6.15

-12 128 141 142 155 156 169 5.38 6.15

-14/-16 151 153 165 167 179 181 5.38 6.15

-18 178 191 192 205 206 219 5.38 6.15

-20 202 215 226 239 228 241 5.38 6.15 nC25 43 57 71 85 99 1 13 5.65 5.85 isoPara 43 57 71 85 99 1 13 5.85 6.15 nC26 43 57 71 85 99 1 13 6.15 6.32 isoPara 43 57 71 85 99 1 13 6.33 6.64

1/2 ring 69 83 97 109 123 137 6.33 7.04

3/4 ring 149 163 177 189 203 217 6.33 7.04

4/5 ring 229 243 257 269 283 297 6.33 7.04

6 ring 309 223 337 6.33 7.04

-6 91 105 1 19 133 147 161 6.33 7.04

-6.1 92 106 120 134 148 162 6.33 7.04

-8/- 10 1 15 1 17 129 131 143 145 6.33 7.04

-12 128 141 142 155 156 169 6.33 7.04

84 -14/-16 151 153 165 167 179 181 6.33 7.04

85 -18 178 191 192 205 206 219 6.33 7.04

86 -20 202 215 226 239 228 241 6.33 7.04

87 nC27 43 57 71 85 99 113 6.65 6.75

88 isoPara 43 57 71 85 99 113 6.76 7.04

89 nC28 43 57 71 85 99 113 7.05 7.20

90 isoPara 43 57 71 85 99 113 7.21 7.45

91 1/2 ring 69 83 97 109 123 137 7.21 7.85

92 3/4 ring 149 163 177 189 203 217 7.21 7.85

93 4/5 ring 229 243 257 269 283 297 7.21 7.85

94 6 ring 309 223 337 7.21 7.85

95 -6 91 105 119 133 147 161 7.21 7.85

96 -6.1 92 106 120 134 148 162 7.21 7.85

97 -8/-10 115 117 129 131 143 145 7.21 7.85

98 -12 128 141 142 155 156 169 7.21 7.85

99 -14/-16 151 153 165 167 179 181 7.21 7.85

100 -18 178 191 192 205 206 219 7.21 ^' 7.85

101 -20 202 215 226 239 228 241 7.21 7.85

102 nC29 43 57 71 85 99 113 7.46 7.65

103 isoPara 43 57 71 85 99 113 7.66 7.85

104 nC30 43 57 71 85 99 113 7.85 8.00

105 isoPara 43 57 71 85 99 113 8.01 8.30

106 1/2 ring 69 83 97 109 123 137 8.01 8.65

107 3/4 ring 149 163 177 189 203 217 8.01 8.65

108 4/5 ring 229 243 257 269 283 297 8.01 8.65

109 6 ring 309 223 337 8.01 8.65

110 -6 91 105 119 133 147 161 8.01 8.65

111 -6.1 92 106 120 134 148 162 8.01 8.65

112 -8/-10 115 117 129 131 143 145 8.01 8.65

113 -12 128 141 142 155 156 169 8.01 8.65

114 -14/-16 151 153 165 167 179 181 8.01 8.65

115 -18 178 191 192 205 206 219 8.01 8.65

116 -20 202 215 226 239 228 241 8.01 8.25

117 nC31 43 57 71 85 99 113 8.30 8.37

118 isoPara 43 57 71 85 99 113 8.38 8.65

119 nC32 43 57 71 85 99 113 8.66 8.79

120 isoPara 43 57 71 85 99 113 8.77 8.99

121 1/2 ring 69 83 97 109 123 137 8.77 9.45

122 3/4 ring 149 163 177 189 203 217 8.77 9.45

123 4/5 ring 229 243 257 269 283 297 8.77 9.45

124 6 ring 309 223 337 8.77 9.45

125 -6 91 105 119 133 147 161 8.77 9.45

126 -6.1 92 106 120 134 148 162 8.77 9.45

127 -8/-10 115 117 129 131 143 145 8.77 9.45

-12 128 141 142 155 156 169 8.77 9.45

-14/-16 151 153 165 167 179 181 8.77 9.45

-18 178 191 192 205 206 219 8.77 9.45

-20 202 215 226 239 228 241 8.77 9.45 nC33 43 57 71 85 99 113 8.95 9.11 isoPara 43 57 71 85 99 113 9.11 9.50 nC34 43 57 71 85 99 113 9.50 9.56 isoPara 43 57 71 85 99 113 9.56 9.92

1/2 ring 69 83 97 109 123 137 9.56 10.51

3/4 ring 149 163 177 189 203 217 9.56 10.51

4/5 ring 229 243 257 269 283 297 9.56 10.51

6 ring 309 223 337 9.56 10.51

-6 91 105 119 133 147 161 9.56 10.51

-6.1 92 106 120 134 148 162 9.56 10.51

-8/-10 115 117 129 131 143 145 9.56 10.51

-12 128 141 142 155 156 169 9.56 10.51

-14/-16 151 153 165 167 179 181 9.56 10.51

-18 178 191 192 205 206 219 9.56 10.51

-20 202 215 226 239 228 241 9.56 10.51 nC35 43 57 71 85 99 113 9.93 10.04 isoPara 43 57 71 85 99 113 10.04 10.51 nC36 43 57 71 85 99 113 10.51 10.67 isoPara 43 57 71 85 99 113 10.67 11.16

1/2 ring 69 83 97 109 123 137 10.67 11.93

3/4 ring 149 163 177 189 203 217 10.67 11.93

4/5 ring 229 243 257 269 283 297 10.67 11.93

6 ring 309 223 337 10.67 11.93

-6 91 105 119 133 147 161 10.67 11.93

-6.1 92 106 120 134 148 162 10.67 11.93

-8/-10 115 117 129 131 143 145 10.67 11.93

-12 128 141 142 155 156 169 10.67 11.93

-14/-16 151 153 165 167 179 181 10.67 11.93

-18 178 191 192 205 206 219 10.67 11.93

-20 202 215 226 239 228 241 10.67 11.93 nC37 43 57 71 85 99 113 11.17 11.28 isoPara 43 57 71 85 99 113 11.29 11.93 nC38 43 57 71 85 99 113 11.94 12.06 isoPara 43 57 71 85 99 113 12.07 12.83

1/2 ring 69 83 97 109 123 137 12.07 14.00

3/4 ring 149 163 177 189 203 217 12.07 14.00

4/5 ring 229 243 257 269 283 297 12.07 14.00

6 ring 309 223 337 12.07 14.00

-6 91 105 119 133 147 161 12.07 14.00

-6.1 92 106 120 134 148 162 12.07 14.00

172 -8/-10 115 117 129 131 143 145 12.07 14.00

173 -12 128 141 142 155 156 169 12.07 14.00

174 -14/-16 151 153 165 167 179 181 12.07 14.00

175 -18 178 191 192 205 206 219 12.07 14.00

176 -20 202 215 226 239 228 241 12.07 14.00

177 nC3 43 57 71 85 99 113 12.83 12.87

178 isoPara 43 57 71 85 99 113 12.88 14.00

a) Rule number, integer index

b) Compound or group of compound rule applies to: 1/2 ring 1/2 ring cycloparaffins 3/4 ring 3/4 ring cycloparaffins 4/5 ring 4/5 ring cycloparaffins 6 ring 6 ring cycloparaffins -6 C _n H2n-6 alkylated benzenes -6.1 C _n H2n-6 linear alkylated benzenes -8/- 10 C _n H2 _n -8 alkylated indanes, C _n H2 _n _ιo alkylated indenes -12 C _n H2 _n _i2 alkylated naphthalenes -14/-16 C _n H2 _n -i4 alkylated acenaphthenes/C _n H2 _n - 16 alkylated acenaphthalenes

-18 C _n H2 _n - 18 alkylated phenanthrenes/anthracenes -20 nH2n-20 alkylated naphthenophenanthrenes

c) Masses used in Rule [up to n may be specified, where n is an integer which is equal to the number of masses scanned during the time interval (d)]

d) Retention time for both starting and ending expected retention times based on historical averages in minutes.

92 3/4 ring 149 163 177 189 203 217 7210 78501 72121 0002 7850 0000 2704187 068%

93 4/5 ring 229 243 257 269 283 297 7210 7850 7212 0002 7850 0000 487096 012%

94 6 ring 309 223 337 7210 7850 7212 0002 7850 0000 269192 007%

95 -6 91 105 119 133 147 161 7210 7850 7212 0002 7850 0000 4363748 110%

96 -6 I 92 106 120 134 148 162 7210 7850 7212 0002 7850 0000 1817821 046%

97 -8/-10 115 117 129 131 143 145 7210 7850 7212 0002 7850 0000 2663527 067%

98 -12 128 141 142 155 156 169 7210 7850 7212 0002 7850 0000 2245793 056%

99 -14/-16 151 153 165 167 179 181 7210 7850 7212 0002 7850 0000 2458246 062%

100 -18 178 191 192 205 206 219 7210 7850 7212 0002 7850 0000 1374209 035%

101 -20 202 215 226 239 228 241 7210 7850 7212 0002 7850 0000 486389 012%

102 nC29 43 57 71 85 99 113 7460 7650 7461 0001 7651 0001 6991682 176%

103 isoPara 43 57 71 85 99 113 7660 7850 7661 0001 7850 0000 4955193 124%

104 nC30 43 57 71 85 99 113 7850 8000 7850 0000 8000 0000 4958373 125%

105 isoPara 43 57 71 85 99 113 8010 8295 8010 0000 8299 0004 6178952 155%

106 1/2 ring 69 83 97 109 123 137 8010 8650 8010 0000 8659 0009 10751285 270%

107 3/4 ring 149 163 177 189 203 217 8010 8650 8010 0000 8659 0009 1907831 048%

108 4/5 ring 229 243 257 269 283 297 8010 8650 8010 0000 8659 0009 196189 005%

109 6 ring 309 223 337 8010 8650 8010 0000 8659 0009 127558 003%

110 -6 91 105 119 133 147 161 8010 8650 8010 0000 8659 0009 3242569 081%

111 -61 92 106 120 134 148 162 8010 8650 8010 0000 8659 0009 1342699 034%

112 -8/-10 115 117 129 131 143 145 8010 8650 8010 0000 8659 0009 1967623 049%

113 -12 128 141 142 155 156 169 8010 8650 8010 0000 8659 0009 1667447 042%

114 -14/-16 151 153 165 167 179 181 8010 8650 8010 0000 8659 0009 1887826 047%

115 -18 178 191 192 205 206 219 8010 8650 8010 0000 8659 0009 1236165 031%

116 -20 202 215 226 239 228 241 8010 8250 8010 0000 8254 0004 146569 004%

168 4/5 ring 229 243 257 269 283 297 12.070 14.000 12.105 0.035 14.035 0.035 0 0.00%

169 6 ring 309 223 337 12.070 14.000 12.105 0.035 14.035 0.035 0 0.00%

170 -6 91 105 1 19 133 147 161 12.070 14.000 12.105 0.035 14.035 0.035 0 0.00%

171 -6.1 92 106 120 134 148 162 12.070 14.000 12.105 0.035 14.035 0.035 0 0.00%

172 -8/- 10 1 15 1 17 129 13 1 143 145 12.070 14.000 12.105 0.035 14.035 0.035 0 0.00%

173 -12 128 141 142 155 156 169 12.070 14.000 12.105 0.035 14.035 0.035 0 0.00%

174 - 14/- 16 151 153 165 167 179 181 12.070 14.000 12.105 0.035 14.035 0.035 0 0.00%

175 -18 178 191 192 205 206 219 12.070 14.000 12.105 0.035 14.035 0.035 0 0.00%

176 -20 202 215 226 239 228 241 12.070 14.000 12.105 0.035 14.035 0.035 0 0.00%

177 nC39 43 57 71 85 99 1 13 12.830 12.870 12.865 0.035 12.905 0.035 791 1 0.00%

178 isoPara 43 57 71 85 99 1 13 12.880 14.000 12.915 0.035 14.035 0.035 106764 0.03%

Sum = 39834154 100.00%

. ^** 8 o

a) Rule number, integer index.

b) Compound or group of compound mle applies to: 1/2 ring 1/2 ring cycloparaffins

3/4 ring 3/4 ring cycloparaffins

4/5 ring 4/5 ring cycloparaffins

6 ring 6 ring cycloparaffins

-6 C _n H2 _n -6 ^a " y' ^ate d benzenes

-6.1 C _n H2 _n -6 linear alkylated benzenes

-8/- 10 C _n H2 _n -8 alkylated indanes, C _n H2 _n _ i o alkylated indenes

-12 _n H2 _n -i2 alkylated naphthalenes

- 14/- 16 C _n H2 _n - 14 alkylated acenaphthenes/C _n H2 _n .1 alkylated acenaphthalenes - 18 _n H2 _n - 18 alkylated phenanthrenes/anthracenes

-20 _n H2 _n -20 alkylated naphthenophenanthrenes

_. c) Masses used in Rule [up to n many be specified, where n is an integer which is equal to the number of masses scanned during the time interval (d to e) either in full scan mode or selected ion monitoring mode].

d) Retention time for both starting and ending expected retention times based on historical averages in minutes.

e) End retention time in minutes.

f) Corrected start retention time.

g) Correction = difference between start and cstart (in minutes).

h) Corrected end time.

i) Correction = Difference between end and cend (in minutes)

j) Abundance, both as total sum and as normalized percentage based on Chemist's Rule.