BS EN 15199-1:2006 pdf download
BS EN 15199-1:2006 pdf download.Petroleum products – Determination of boiling range distribution by gas chromatography method- Part 1: Middle distillates and lubricating base oils.
8 Preparation of the apparatus
81 Gas chromatograph preparation
8.1.1 Set up and operate the gas chromatograph in accordance with the manufacturers instructions.
Typical operating conditions are shown in Table 2.
81.2 Deposits may form on the jet from combustion of decomposition products from the liquid stationary phase These will affect the characteristics of the detector and should be removed
NOTE The following parawneters are affected by deposits on the tet increase in inlet pressure. FtC) difficult to lighl increase in the CS response and an off specification reference material To clean the let, it is recommended that it is put in an ultrasonic cieaner with a suitable soivenl, and a cleaning wire ed.
8.2 System performance check
Check the system perkxmance at the intervals given and by the procedures specified In Annex B.
9 Sample preparation
Make a 2110Oml to 39!lOOml solution of the sample in carbon disullide Transfer to an autosampler vial and immediately cap
CAUTION — It is recommended that all work with carbon disulfide is carried out in an explosion protected fume cupboard.
10 Calibration
10.1 Carry out the steps given in 10 2 to 104 each day before sample analysis The fast run o( the day shall not be a blank, a reference matenal or a sample. due to the possible elution of extraneous components wtiich have built up in the injector, but it may be the calibration mixture (5.8).
10,2 Fêjn the calibration mixture (5.8) using the specified procedure described in Clause 11.
NOTE Take care to ensure the lest portion volume chosen does not allow any peak to exceed the linear range OS the detector, or overload the column A skew of> 3 incates the s.nple Is too concentrated and a skew of C 1 indicates an old column or dirty liner As a gue, li of me cabration mixture 158) has been found to be suitable for columns with film thickness less than 0 17 im
10.3 Record the retention time of each component and plot the retention time versus the atmospheric boiling point for each component to obtain the calibration curve
NOTE The atnxsphenc boning points of me alkanes are given in Annex C.
A typical chromatograni of the calibration mixture (5 81 IS given in Figure 4 and a typical calibration curve is given in Figure 5.
A.12 Blank data array. N area slices
The slice width for the blank and sample runs shall be identical
NOTE A blank data array may not be necessary if electronic baseline compensation is used see A2)
The analysis nditions for blank and sample shall be identical through the point ere sample analysis is terminated.
The number of slices in the blank array shall be equal to or greater than the number of slices in the sample ctiromatogram. If the number of slices In the blank array is greater than the number of slices In the sample array then drop the extra slices in the blank array This situation could occur if a blank run extended beyond the point whefe the sample analysis was teminated,
A.1.3 Retention times of n-parafflns
The retention lime of each n-paraffin in the calibration mixture shall be obtained from a processed ipeak) data
file from the analysis of the calibration mixture, run under identical conditions as the samples and blank A.1.4 Boiling points of n-paraffins
The boiling point of each n-paraffin in the calibration mixture (to the nearest whole degree Celsius) can be obtained front Table C. 1.
A.1.5 Solvent exclusion time
The solvent exclusion time is that time when the signal has rettxned to baseline after elubon of the solvent This parameter is used to exclude area due to the solvent used, ii any If a solvent is used, the detector signal has to return to baseline before any sample components start to elule.
A.2 Subtraction of the blank from the sample
Subtract each blank area slice from the exactly corresponding sample area slice This corrects the sample area slice from the blank.
If the data was acquired on an instrument using automatic basetine compensation, this paragraph may be skipped In this case, the zeroed sample data array contains the corrected area slices to be used in subsequent calculations.
