Barbro Andersson

Evaluation of adsorbents for sampling and quantitative analysis of microbial volatiles using thermal desorption-gas chromatography

Abstract Eight adsorbents were evaluated for sampling and quantitative analysis of microbially produced volatiles using thermal desorption-gas chromatography. The adsorbents studied were Tenax TA, Tenax GR, Chromosorb 102, Carbotrap C, Carbopack B, Anasorb 727, Anasorb 747 and Porasil C/ n -octane (Durapak). The study was performed using a test atmosphere consisting of ten compounds differing in polarity and volatility: 2-propanol, dimethyl disulfide, toluene, furfural, 1-octen-3-ol, 3-octanone, 3-octanol, 2-isopropyl-3-methoxypyrazine, 2-methylisoborneol and geosmin. The adsorbents were tested under conditions found in “sick buildings”—low μg/m 3 levels and varying humidity. Tenax TA proved to have the best properties considering the amount obtained, breakthrough and standard deviation during sampling/analysis.

Immunoaffinity column clean-up for the high-performance liquid chromatographic determination of aflatoxins B1, B2, G1, G2, M1 and Q1 in urine.

A method for the determination of aflatoxins B1, B2, G1, G2, M1 and Q1 in human urine has been developed. The 10-ml urine samples were automatically cleaned up on immunoaffinity columns and analysed by high-performance liquid chromatography (HPLC), including post-column derivatization with bromine and fluorescence detection. Average aflatoxin recoveries were: B1 103%, B2 106%, G1 98% and G2 96% in the range 6.8-73 pg/ml of urine and M1 103% and Q1 100% in the range 18-97 pg/ml of urine. The relative standard deviations were all between 1% and 21%. The determination limits of aflatoxins in urine were 6.8 pg/ml for B1, B2, G1 and G2 and 18 pg/ml for M1 and Q1.

Analysis of fatty acids. A new method for characterization of moulds

Aspergillus flavus, A. oryzae, A. fumigatus, Penicillium roqueforti, P. verrucosum, P. viridicatum, Mucor hiemalis, M. plumbeus and M. piriformis were cultivated on standardized media. The spores were harvested and the fatty acids of the spores transesterified. The fatty acid methyl esters were analysed by gas chromatography, and the fatty acids data were subjected to multivariate statistical analyses by SIMCA (Soft Independent Modelling of Class Analogies) pattern recognition. The results showed that this method enables various species of the moulds to be identified in a reproducible way.

Determination of aflatoxins in airborne dust from feed factories by automated immunoaffinity column clean-up and liquid chromatography

Abstract A method for the determination of aflatoxins in airborne dust is described. The dust samples were extracted with acetone-water, cleaned up on immunoaffinity columns and analysed by HPLC, including a post-column derivatization reaction with bromine and fluorescence detection. The method was evaluated with filters spiked with 62–595 pg of aflatoxins B 1 , B 2 , G 1 and G 2 , respectively. Average aflatoxin recoveries for B 1 , B 2 , G 1 and G 2 were 97, 101, 87 and 84%, respectively. The method was used for airborne dust collected at feed factories. The detection limit was 3.1 ng/g dust for aflatoxins B 1 , G 1 and G 2 and 1.8 ng/g for aflatoxin B 2 , for a 10-mg dust sample.

Exposure to Ski-Wax Smoke and Health Effects in Ski Waxers

Abstract Downhill as well as cross-country skis have undergone revolutionary technical development in recent decades. Parallel with innovations in ski bottoms, new types of ski wax have appeared on the market. At the same time complaints have been voiced increasingly by those who wax skis. We followed five male professional waxers at work in this combined chemical and medical study. Chemical analysis of some common ski waxes showed that they consist mainly of a mixture of straight-chain aliphatic hydrocarbons. Some waxes also contain mixtures of silicone compounds in unknown amounts. One brand consisted entirely of a polytetrafluoroethylene (PTFE). The individual components vaporize on heating, and on cooling in the air they condense rapidly to smoke consisting of particles less than 1 μm in diameter. Particles of this size might reach down into the pulmonary alveoli on inhalation. All ski waxes may be expected to behave in the same way, whether they contain paraffin, PTFE, or silicone. The results show t...

Automated sample clean-up with solid-phase extraction for the determination of aflatoxins in urine by liquid chromatography.

An automated extraction and clean-up procedure was developed for the determination of aflatoxins in human urine at the 50 pg/ml level. Aflatoxins B1, B2, G1 and G2 are captured on C2 extraction columns and simultaneously cleaned up with the aid of a robotic system. The processed samples are analysed by reversed-phase high-performance liquid chromatography. Fluorescence detection was enhanced for aflatoxins B1 and G1 using factorial design optimization of the post-column reactor. Silylation of the glass vials used in the robotic system was of the utmost importance. With non-silylated glass vials, up to 75% of the analytes were lost. Average aflatoxin recoveries were B1 95%, B2 90%, G1 93% and G2 89%.

Thermal desorption cold trap-injection in high-resolution gas chromatography: multivariate optimization of experimental conditions

In studies of low concentrations of volatile compounds in air, the method of adsorption on porous polymers and determination by thermal desorption cold trap-injection high-resolution gas chromatography is finding increasing application. Factors considered important for injection and chromatographic separation of volatile compounds by this method were investigated with the use of multivariate techniques. For the amount injected on to the chromatographic column, the factors of main importance were found to be the temperature of the injection block, the thickness of the internal coating of the cold trap and the flow-rate. Strong interaction effects were noted. For the sharpness of the chromatographic peaks, the flow-rate was the most important factor.

Determination of N-acetyl-S-(2-phenyl-2-hydroxyethyl)cysteine in human urine after experimental exposure to styrene

Abstract An assay for determination of one of the styrene mercapturic acids [(N-acetyl-S-(2-phenyl-2-hydroxyethyl)cysteine] was developed. Styrene mercapturic acid in urine samples was determined using high performance liquid chromatography (HPLC) with electrochemical detection. Urine samples from 6 individuals who had been experimentally exposed to styrene (205–220 mg/m3, 2 hrs, 50 W) were analysed using our assay. The absorption of styrene during the exposure was 3.6 mmol (range 3.2–4.1) or 64% of the amount inhaled. N-acetyl-S-(2-phenyl-2-hydroxyethyl)cysteine could not be identified in the urine collected during the exposure and up to 5 hrs from the end of the exposure. If present, the metabolic yield from absorbed styrene was less than 1%. Our results, in contrast to what have been reported from animal experiments, indicate that, in man, gluthatione conjugation of styrene to mercapturic acids is a metabolic pathway of less importance and/or that styrene-glutathione conjugates in man undergo a metabolism different from that which has been reported in rats.

Determination of Tertiary Amines in Air

Abstract Methods have been developed for air sampling of gaseous tertiary amines on solid sorbents. Sampling was performed at three different air levels and at 20 percent and 85 percent relative air humidity, respectively. Desorption was carried out by solvent extraction prior to high-resolution gas chromatographic analysis with flame ionization or nitrogen-phosphorus detection. Seven amines, differing in the length and shape of the carbon chains, were selected for the study and divided into three groups. The members of the first group, consisting of dimethylethylamine (DMEA), methyldiethylamine (MDEA), and triethylamine (TEA) were collected using charcoal tubes and desorbed with 5 percent ethanol in dichloromethane. The amine air levels were 1, 10, and 50 ppm. The recoveries of these amines were 92–100% (n = 6, RSD = 1–4%). Storage studies (5 days at room temperature followed by 9 days in a freezer) showed recoveries of 87 percent (DMEA), 89 percent (MDEA), and 82 percent (TEA). Determination of DMEA in ...

Determination of aflatoxin Q1 in urine by automated immunoaffinity column clean-up and liquid chromatography

A liquid chromatographic system with an automated clean-up procedure for aflatoxin Q1 in human urine is described. The samples were cleaned up by using immunoaffinity columns originally designed for aflatoxin M1. The chromatographic system was a C18 column with an acidic mobile phase of acetonitrile-water containing potassium bromide. Fluorescence detection (365/440 nm) of aflatoxin Q1 was enhanced by addition of bromine, using post-column derivatization, which was studied by factorial designs. Average recovery of aflatoxin Q1 in spiked 10-ml urine samples was 88% (R.S.D. = 6.4%) at a level of 50 pg/ml. The determination limit was 49.5 pg/ml urine.