Sampling of ethylene glycol and ethylene glycol derivatives in work-room air using Amberlite XAD resins

The porous polymers Amberlite XAD-2 and XAD-7 were evaluated for the sampling of ethylene glycol, 2-methoxyethanol, 2-ethoxyethanol, 2-butoxyethanol and 2-ethoxyethyl acetate in work-room air. Using diethyl ether desorption, these adsorbents were found excellent for the compounds studied.     

Analysis of gaseous diisocyanates in air using chemosorption sampling

A sampling procedure for 2,4- and 2,6-toluenediisocyanate (TDI) and 4,4′-diphenylmethane diisocyanate (MDI) in the range 0.007-0.7 mg/m³ in a 15 L air sample is described. The sampling is performed with 9-(N-methylaminomethyl)-anthracene (MAMA) adsorbed on a solid sorbent, Amberlite XAD-2. The recoveries are 80–100% in this chemosorption reaction. The urea derivatives are desorbed with N,N-dimethylformamide and analysed by high performance liquid chromatography (HPLC). Samples and prepared chemosorption tubes are stable for at least two weeks if stored in the dark. To complete the investigation, field measurements of TDI were performed in an industrial atmosphere.     

Phenolic compounds in oat grains (Avena sativa L.) grown in conventional and organic systems

The concentrations of avenanthramides (AVAs), hydroxycinnamic acids (HCAs), a sucrose-linked truxinic acid (TASE), and certain agronomic parameters were analyzed in organically and conventionally grown oats. Three cultivars of oats (i.e. Freja, Sang, and Matilda) were grown according to standards for both conventional and organic farming in Sweden, from 1998 to 2000. Two levels of nitrogen (N) and three replicates were included. Overall, there were significant differences between years, cultivars, and N rate for AVA concentration in the grains, but there were no differences in concentration as a consequence of the conventional or organic cropping system used. The AVA content was higher in the samples grown in 2000, particularly in the cultivar Matilda, and was negatively affected by higher N rates. The HCAs showed cultivar and year differences, but were not influenced by N rates or the cropping system. The HCA content was highest in Matilda, and was significantly lower in samples grown in 1999. The concentration of TASE differed only between years, and was about 100% higher in samples from 1999, compared with samples from 1998 and 2000. The AVA and HCA concentrations were negatively correlated to the yield and specific weight of the grains and positively correlated to the protein content. Conversely, the concentration of TASE was positively correlated to the yield. The specific parameters responsible for the variation in the phenolic compounds are not known, but it seems that factors affecting the yield and/or the specific weight also affect the concentrations of AVAs, HCAs, and TASE in oat grains.     

Influence of air humidity on sampling efficiency of some solid adsorbents used for sampling organics from work-room air

The influence of air humidity on the sampling efficiency of Amberlite XAD porous polymers and activated charcoal was studied by determining the recovery of various organics at 20% and 85% relative humidity. The sampling efficiency of XAD-7 was found to decrease with increasing relative humidity, while the sampling efficiency of XAD-2 and activated charcoal was relatively unaffected for the compounds studied. Activated charcoal had a greater capacity than Amberlite XAD for several types of compounds, however.     

Occupational exposure

Concentrations of polychlorinated biphenyls (PCB), polychlorinated naphthalenes (PCN), polychlorinated dibenzo-p-dioxins (PCDD), polychlorinated dibenzofurans (PCDF), hexachlorobenzene and methylsulphonyl metabolites of PCB were determined in blood plasma from potentially exposed workers and controls. Three of the potentially exposed subjects had worked with cable incineration and two were electricians. Extraction of the organochlorine compounds and lipids were performed using the lipophilic gel Lipidex. Different adsorbents and gel permeation chromatography were applied for further purification of the samples and separation of analytes. Determinations of the chlorinated compounds were made by using gas chromatography with electron-capture detection and gas chromatography-mass spectrometry. Only small differences in the concentrations of organochlorine compounds were found in the plasma from the three subject groups. Thus, specific exposure of the workers could not be confirmed.