Key words: HPLC, latex, test method, standards
ASTM Committee D11.40 Chemical Sensitivity Task Group met five times in FY 96 and FY 97 and conducted several methods development round robin studies. The standards of sodium salt of diethyldithiocarbamic acid, 2-mercaptobezothiazole, tetramethylthiuram disulfide and sulphenamide were evaluated using an HPLC method with various combinations of mobile phase, detecting UV wave length and the stability of the standards. The task group also studied the extraction of some specially prepared latex samples and used the HPLC method to determine those sensitive chemical compounds in the latex samples.
From these studies, the task group found that the carbamate standard was not very stable in the working solution for longer than 2 hours. Different buffer solutions with several values of pH also had been studied. The HPLC results showed that there were three different peaks in the chromatogram of the carbamate standard, which complicated the analytical result. The analytical procedures for the other standards were quite straightforward.
The task group also used a colorimetric method with copper sulfide to evaluate an alternative method for carbamate determination.
OST had participated in most of the meetings to discuss the round robin study result and all the laboratory studies. OST was also involved in rewriting the round robin protocol for the HPLC method and the colorimetric method.