ASTM D7771-17 pdf free.Standard Test Method for Determination of Benzo-α-Pyrene (BaP) Content in Carbon Black.
Reagent-grade chemicals shall beused in all tests.Unless otherwise indicated, it is intended thatall reagents conform to the specifications of the Committee onAnalytical Reagents of the American Chemical Society wheresuch specifications are available.3 Other grades may be used,provided it is first ascertained that the reagent is of sufficientlyhigh purity to permit its use without lessening the accuracy ofthe determination.
Separate stock solutions of the native BaP standards andof the internal standard (deuterated or C13-labeled) can bepurchased as premade solutions or prepared from solid mate-rials (Table 1).A concentration range of 80 to 100 ug/cm for thenative BaP analyte stock solution is recommended.
All purchased BaP standard materials shall be 98 %pure or better and certified with respect to their purity andconcentration by the manufacturer. Follow the manufacturer’srecommendation on how best to store the standard solutions.Typically,the compounds are protected from light. Theyshould be checked frequently for signs of degradation orevaporation. The BaP standard stock solutions shall bereplaced/recertified on a yearly basis or sooner if comparisonswith quality control (QC) samples indicate a problem.Toluene，suitable for high resolution gas chromatogra-phy analysis (99.99 % pure).
Acetone，suitable for high resolution gas chromatography analysis (99.99 % pure).Helium,GC/MS purity grade.7.6 Nitrogen, analytical purity grade.
Silica gel columns for Solid Phase Extraction (SPE)removal of polar compounds.Extract samples continuously for 16 h and the toluenelevel should be checked from time to time for potential lossesthrough evaporation.To avoid degradation of the extracted BaPby overheating of glass walls, a sufficient level of toluene shallalways remain in the boiling flask especially at the point atwhich the Soxhlet is filled and the solvent is starting to siphonout.
If the remaining solvent volume becomes too small,the extraction has to be interrupted and fresh toluene be addedto the extractor after cool down.The nitrogen flow should bechecked and adjusted, if necessary.The extraction is subse-quently continued to complete the required extraction time.