BS EN ISO 9377-2 pdf free download

BS EN ISO 9377-2 pdf free download. Water quality – Determination of hydrocarbon oil index – Part 2: Method using solvent extraction and gas chromatography.
4 Interferences Compounds of low polarity (e.g. halogenated hydrocarbons) and high concentrations of polar substances can interfere with the determination. Surface-active substances interfere with the extraction step. 5 Principle The water sample is extracted with an extracting agent. Polar substances are removed by clean-up on Florisil. The purified aliquot is analysed by capillary chromatography using a non-polar column and a flame ionization detector (FID). The total peak area between n-decane and n-tetracontane is measured. The concentration of mineral oil is quantified against an external standard consisting of two specified mineral oils, and the hydrocarbon oil index is calculated. It is absolutely essential that the test described in this part of ISO 9377 be carried out by suitably qualified staff. It should be investigated whether and to what extent particular problems will require the specification of additional marginal conditions. 6 Reagents All reagents shall be reagent grade and suitable for their specific purpose. The suitability of the reagents and solutions shall be checked by carrying out a blank test. 6.1 Water for the preparation of solutions. Distilled water, or water from a generator of purified water capable of removing organic traces, for example using activated carbon, shall be used. 6.8 Mixture of mineral oils. 6.8.1 Standard 2) mixture. Weigh accurately equal amounts of two different types (type A and type B, both containing no additives) of mineral oil and add enough extraction solvent (6.1 1 .2) to give a total hydrocarbon concentration of about 1 0 mg/ml. Type A should show discrete peaks in the gas chromatogram. An example is diesel fuel without any additives. See EN 590 for further information. Type B should have a boiling range higher than that of type A and should have unresolved signals in the gas chromatogram. An example of this type is a lubricant without any additives, boiling range 325 ? C to 460 ? C. 6.8.2 Calibration mixture. Prepare at least five different calibration solutions by diluting aliquots of standard mixture (6.8.1 ) with the extraction solvent (6.1 1 .2). The following concentrations may be suitable: 0 (blank), 0,2 mg/ml, 0,4 mg/ml, 0,6 mg/ml, 0,8 mg/ml and 1 ,0 mg/ml. Higher concentrations may be advisable for other applications. Store the calibration mixture tightly sealed in a refrigerator (4 ? C to 8 ? C). The calibration mixtures are stable for up to six months. 6.8.3 Quality Control (QC) standard. Prepare a standard solution according to 6.8.1 in acetone (see 6.6) with a mass concentration of e.g. 1 mg/ml. The exact concentration should be about a thousand times the desired application range. NOTE When using a lubricant for QC, the stock solution is easily prepared in extracting agent (6.2), which is further diluted in acetone about tenfold before spiking the QC water. Store the solution tightly sealed in a refrigerator (4 ? C to 8 ? C). It is stable for up to six months. 6.9 Standard mixture of n-alkanes for system performance test. Dissolve n-alkanes with even carbon numbers (C 20 , C 40 and at least three further n-alkanes) in extracting agent (6.2) to give concentrations of approximately 50 ?g/ml of the individual components. It may be necessary to use a different solvent, e.g. heptane, for the first solution; in this case dilute this first solution with extracting agent (6.2). Store the standard mixture tightly sealed in a refrigerator. It is stable for up to six months.BS EN ISO 9377-2 pdf download.