Analysis of sodium polyacrylate absorbent dust using ultra-trace sodium analysis—a seven-company collaborative study

Seven companies that either manufacture cross-linked polyacrylate absorbents (PA) or manufacture products that contain PA have developed in situ methods to measure trace levels of PA dust. The method uses sodium present in PA as the tracer element and involves careful pre-cleaning of sampling cassettes and filters. Cassette and filter pre-cleaning as well as sample collection, extraction, and analysis are carried out in a sealed cassette assembly, hence the term “in situ”. Inadvertent contamination of the cassette assembly during shipping and handling or during solution transfer is thereby eliminated. Limits of detection for PA range from 0.11 to 2.4 μgm3 and the seven companies averaged 0.7 μgm3. This report contains the results of an inter-company collaborative trial conducted to assess the accuracy, precision, and limits of detection for the in situ methods used by the seven companies.