A method based on high-performance liquid chromatography (HPLC) with electrochemical detection is described for the determination of aromatic and aliphatic isocyanates in air. 1-(2-Methoxypheny1)piperazine is used as the electrogenic reagent. It forms electrochemically active derivatives with all of the isocyanates of occupational hygiene interest that are readily oxidised a t carbon electrodes. In addition, these derivatives are strongly absorbing in the ultraviolet region, enabling a combination of electrochemical and ultraviolet detectors to be employed to provide additional qualitative information if required.Comparison is made between the electrochemical detection method and HPLCultraviolet detection methods for isocyanate analysis. The electrochemical detection method was found to be significantly more sensitive than the ultraviolet detection methods for the determination of phenyl isocyanate, toluene diisocyanate, hexamethylene diisocyanate and (4,4'-diisocyanato-dipheny1)methane in air.
This paper describes workplace dermal exposure measurements that were carried out by the Health and Safety Laboratory as part of the EU RISKOFDERM project. Exposure to metalworking fluids (MWFs) was measured at three sites on 25 subjects who were 'mechanically treating solid objects' as they loaded and supervised milling and boring machines and lathes. Thirty-one samples were obtained, of which 18 were exposures to neat mineral oils and 13 to water-oil mixes. All subjects wore Tyvek whole-body oversuits that were analysed in their entirety to extract the MWF. The geometric mean surface loading rate of the 31 oversuits was 62 micro g/cm(2)/h (GSD = 4.6) and of the seven pairs of sampling gloves (worn inside protective gloves) was 2900 micro g/cm(2)/h (GSD = 1.67). Exposure to electroplating fluids was measured at three sites on 27 subjects who were dipping objects into tanks of either chromic acid, nickel sulphate, copper sulphate, copper cyanide or zinc hydroxide. All subjects wore Tyvek whole-body oversuits that were surface scanned over their areas using a portable X-ray fluorescence spectrometer to detect all the metal atoms simultaneously. Contamination was assessed using the method of Dirichlet tessellation. The geometric mean surface loading rate of the 26 oversuits was 37 micro g/cm(2)/h (GSD = 3.5) and of the 25 pairs of sampling gloves (worn inside protective gloves) was 190 micro g/cm(2)/h (GSD = 2.75). Almost all of the electroplating samples were below the limit of quantification. More than one species of metal atoms was found on some of the samples afterwards, indicating cross-contamination from other baths during the sampling period.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.