Method for detecting asbestos
Asbestos testing methods are many, because the asbestos environment is different, the purpose of evaluation is different, the choice of methods are different, so there is no test can solve all the problems. Only by combining them to ensure the validity and accuracy of the detection, the main methods of combining XRD and PLM two instruments are used as the technical methods of asbestos detection in industrial products.
benzoic acidOneDetermination and scope of application of the subject content. This standard specifies sorbic acid and benzoic acid content in soy sauce, fruit juice, jam and other foods.This standard applies to soy sauce, fruit juice, jam and other food sorbic acid, benzoic acid content determination.Minimum detectable concentration: 1 microgram gas chromatography minimum detectable quantity, sample chromatographic analysis, 1G, minimum detectable concentration of 1mg / kg.The first method of gas chromatography (first method)2 PrincipleThe sample was acidified with diethyl ether, sorbic acid, benzoic acid, and extracted by hydrogen peroxide flame ionization detector. The samples were separated by gas chromatography and compared with the standard series.3 reagent3.1 ether: no peroxide.3.2 petroleum ether: the boiling range is 3060 degrees centigrade.3.3 hydrochloric acid.3.4 drying with anhydrous sodium sulfate.3.5 hydrochloric acid (1 + 1): take hydrochloric acid, dilute with water to 200 ml 100 ml. Sodium Chloride Solution (40 g / L) with a small amount of hydrochloric acid (1 + 1) and acidified:3.6 of the acidic sodium chloride (40 g / L) was found in the solution.3.7 sorbic acid, benzoic acid standard solution: weigh accurately sorbic acid, benzoic acid, 0.2000 grams each, placed in a 100mL flask, with petroleum ether ethyl ether (3 + 1) dissolved and mixed solvent diluted to the mark. The solution is equivalent to 2.0mg per milliliter of sorbic acid or benzoic acid.3.8 sorbic acid, benzoic acid standard solution: absorb sorbic acid, use the standard solution of petroleum ether, benzoic acid, right amount - ether mixed solvent (3 + 1) to the equivalent 50100150200250mg sorbitol of every milliliter or benzoic acid.
