BS EN 12916:2000 pdf download.Methods of test for petroleum and its products一 BS 2000 391: Petroleum products一Determination of aromatic hydrocarbon types in middle distillates 一High performance liquid chromatography method with refractive index detection ( Identical with IP 391 -2001)
6 Apparatus 6.1 Liquid chromatograph, consisting of a high performance instrument capable of pumping the mobile phase at flow rates of between 0,5 m/min and 1,5 ml/min， with a precision better than 0,5 % and a pulsation of< 1 % full scale deflection under the test conditions described in clause 8. 6.2 Sample injection system, capable of injecting 10 μl (nominal) of sample solution with a repeatability of better than 1 %. NOTE 1 Equal and constant volumes of the calibration and sample solutions are injected into the chromatograph. Both manual and automatic sample injection systems (using either complete or partial flling of the sample loop), when used correctly, can meet these repeatability requirements. When using the partial flling mode, it is recommended that the injection volume should be less than half the total loop volume. For complete flling of the loop, best results are obtained by overfilling the loop at least six times. The repeatability of the injection system may be checked by comparing peak areas from at least four injections of the system calibration standard (see 8.3). NOTE 2 Sample and calibration injection volumes different from 10 μl (typically in the range 3 μl to 20 μl) may be used provided they meet these requirements for injection repeatability, refractive index sensitivity and linearity (see 9.4), and column resolution (see 8.6). 6.3 Sample filter, if required (see 10.1), consisting of a microfilter of porosity 0,45 μm or less, chemically inert towards hydrocarbon solvents, for the removal of particulate matter from the sample solutions. 6.4 Column system, consisting of a stainless steel HPLC column(s) packed with a commercial 3 um, 5 μm or 10 μm amino-bonded (or amino/cyano-bonded) silica stationary phase meeting the resolution requirements given in 8.6. See Annex A for guidance on the selection and use of suitable column systems.
6.6 Backflush valve, consisting of a manual, or air or electrically actuated automatic, flow-switching valve designed for use in HPLC systems, capable of operating at pressures up to2 x 104 kPa. 6.7 Refractive index detector, capable of being operated over the refractive index range 1,3 to 1,6 and giving a linear response over the calibration range with a suitable output signal for the data system. NOTE If the detector has a facility for independent temperature control, it is recommended to set it at the same temperature as the column oven. 6.8 Computer or computing integrator, compatible with the refractive index detector, having a minimum sampling rate of 1 Hz and capable of peak area and retention time measurement. It shall also have minimum facilities for post- analysis data processing such as baseline correction and re-integration. NOTE The ability to perform automatic peak detection and identification and to calculate sample concentrations from peak area measurements is recommended, but is not essential. 6.9 Volumetric flasks, 10 ml and 100 ml capacity, conforming to ISO 1042, grade B or better. 6.10 Analytical balance, capable of weighing to the nearest +0,0001 g.BS EN 12916 pdf download.