Abstract  1,4-Dioxane has been classified by the US Environmental Protection Agency and the International Agency for Research on Cancer as a compound that may be carcinogenic in humans. Although there are several reports of 1,4-dioxane being detected in the environment, such as in tap water, there have been few reports on the content of 1,4-dioxane in food. We therefore studied the intake of 1,4-dioxane in food based on the average intake of food in the Kanto area of Japan as reported by the Ministry of Health, Labor and Welfare. The food was cooked in the normal manner and then homogenized in a mixer. A 20 g of sample of the homogenate was added to a solution of the purified water with 0.2 μg of 1,4-dioxane-d_8 as a surrogate and the 200 ml azeotropic solution was recovered using the steam distillation method. This solution was applied to a pair of active carbon solid-phase cartridges and the analyte was eluted from each cartridge with dichloromethane. The eluted solution was prepared for gas chromatographic/mass spectrometric analysis by reduction to a volume of 1 ml under a gentle stream of nitrogen. The detection limit of the analysis was 2 μg/kg. We found that the 1,4-dioxane content of 12 food groups ranged between 2 μg/kg and 15 μg/kg. From these results, the total daily intake of 1,4-dioxane was calculated to be 0.440 μg. An intake of this magnitude corresponds to 0.055% of the calculated total daily intake (TDI) (16 μg/kg body weight/day). This study indicates that the amount of 1,4-dioxane intake contributed by food is very low and that this value does not represent a potential problem as it does not raise the risk of carcinogenesis.

Abstract  Authentication of farm animal rearing conditions, especially the type of feeding, is a key issue in certification of meat quality and meat products. The purpose of this article was to analyze in parallel the volatile fraction of three adipose tissues excised from 16 lambs in order to authenticate two animal diets: pasture (n = 8) and concentrate (n = 8). On the basis of growth rate and anatomical location, three different lamb adipose tissues were analyzed: perirenal fat (PRF), caudal subcutaneous fat (CSCF), and heart fat (HF). An initial experiment was used to optimize the extraction of volatile compounds from the adipose tissues. Using a lipid liquid phase extraction, heating the ground tissue to 70 degrees C, was shown to be the best sample preparation mode before dynamic headspace-gas chromatography-mass spectrometry (DH-GC-MS) analysis to achieve a good representation of the starting material, while getting a good extraction and reproducibility. Next, the application of an instrumental drifts correction procedure to DH-GC-MS data enabled the identification of 130 volatile compounds that discriminate the two diets in one or several of the three tissues: 104 were found in PRF, 75 in CSCF, and 70 in HF. Forty-eight of these diet tracers, including 2,3-octanedione, toluene, terpenes, alkanes, alkenes, and ketones, had previously been identified as ruminant pasture-diet tracers and can be considered generic of this type of animal feeding. Moreover, 49 of the 130 compounds could identify diets in only one tissue, suggesting that complementary analysis of several tissues is superior for diet identification. Finally, multivariate discriminant analyses confirmed that the discrimination was improved when PRF, CSCF, and HF were considered simultaneously, even if HF contributed minimal information.

Abstract  The volatile and polar solvent 1,4-dioxane has recently been reported as a contaminant of ground and surface waters, establishing the need to determine this substance in drinking water. This investigation established that 1,4-dioxane can be determined in water by various techniques including direct aqueous injection (DAI) gas chromatography (GC) and purge and trap GC-mass spectrometry (MS). Purge and trap GC-MS is limited by 1,4-dioxane's poor purge efficiency, resulting in detection limits up to 100 times greater than the efficiently purged volatile organic compounds. To attain the sensitivity required for drinking water monitoring, a method based on continuous liquid-liquid extraction with dichloromethane was developed. Isotope dilution was more accurate and reproducible than quantification with external standards, and the improvement in precision led to a lower method detection limit, 0.2 mu g L-1, using a quadrupole ion trap instrument in the electron ionization mode. Isotope dilution accuracy approached 100% in ppb determinations. Isotopic dilution quantification was also possible using a non-selective GC detector owing to the high efficiency of capillary GC columns that resolve the deuterium-labeled solvent from the natural isotopes.

Abstract  NOABSTRACT - no abstract found

Abstract  1,4-Dioxane impurity in nonionic surfactants and cosmetics were analyzed using solid-phase microextraction (SPME) coupled with gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). Experimental results show that there is no significant difference using SPME-GC and SPME-GC-MS for analysis of 1,4-dioxane in three types of nonionic surfactants at the 95% confidence level. The relative standard deviation (R.S.D.) values of each analytical method were smaller than 3%. The amount of 1,4-dioxane was found to vary from 11.6 +/- 0.3 ppm to 73.5 +/- 0.5 ppm in 30% of nonionic surfactants from manufacturers in Taiwan. These methods were linear over the studied range of 3-150 ppm with correlation coefficients higher than 0.995. The recoveries of 1,4-dioxane for these nonionic surfactants following SPME were all higher than 96 +/- 1% (n = 3). The detection limits of 1,4-dioxane for these nonionic surfactants following SPME were from 0.06 ppm to 0.51 ppm. The experimentally determined level of 1,4-dioxane in cosmetics from manufacturers in Taiwan varied from 4.2 +/- 0.1 ppm to 41.1 +/- 0.6 ppm in 22% of daily used cosmetics following SPME coupled with GC and GC-MS. Conventional solvent extraction takes around 1 h for extraction and reconcentration but SPME takes only around 10 min. SPME provides better analyses of 1,4-dioxane in nonionic surfactants and cosmetics than conventional solvent extraction and head space pretreatments in term of simplicity, speed, precision, detection limit, and solvent consumption.

Abstract  Vehicle garages often contain high concentrations of volatile organic compounds (VOCs) that may migrate into adjoining residences. This study characterizes VOC concentrations, exposures, airflows, and source apportionments in 15 single-family houses with attached garages in southeast Michigan. Fieldwork included inspections to determine possible VOC sources, deployment of perfluorocarbon tracer (PFT) sources in garages and occupied spaces, and measurements of PFT, VOC, and CO(2) concentrations over a 4-day period. Air exchange rates (AERs) averaged 0.43+/-0.37 h(-1) in the houses and 0.77+/-0.51 h(-1) in the garages, and air flows from garages to houses averaged 6.5+/-5.3% of the houses' overall air exchange. A total of 39 VOC species were detected indoors, 36 in the garage, and 20 in ambient air. Garages showed high levels of gasoline-related VOCs, e.g., benzene averaged 37+/-39 microg m(-3). Garage/indoor ratios and multizone IAQ models show that nearly all of the benzene and most of the fuel-related aromatics in the houses resulted from garage sources, confirming earlier reports that suggested the importance of attached garages. Moreover, doses of VOCs such as benzene experienced by non-smoking individuals living in houses with attached garages are dominated by emissions in garages, a result of exposures occurring in both garage and house microenvironments. All of this strongly suggests the need to better control VOC emissions in garages and contaminant migration through the garage-house interface.

Abstract  The pharmacokinetics and metabolism of 1,4-dioxane were determined in four healthy male volunteers exposed to 50 ppm dioxane vapor for 6 hr. Samples of blood and urine collected during and after the exposure were analyzed for dioxane and its metabolite β-hydroxyethoxyacetic acid (HEAA) by gas chromatography-mass spectrometry. A pharmacokinetic model with associated parameters was constructed to describe the fate of dioxane and HEAA in humans. The model was compared to a model constructed previously for dioxane in rats. This comparison facilitates assessment of the hazard to humans of dioxane exposure by extrapolation of toxicological information obtained in rats. The dynamics of dioxane uptake and elimination in humans could be described by a one-compartment open-system model with zero-order uptake and first-order elimination. The half-life for elimination of dioxane was 59 + 7 min; 99.3% of the elimination was by metabolism of dioxane to HEAA, and 0.7% was by excretion of dioxane in the urine. Dioxane and HEAA were detectable in the urine until 6 and 18 hr after cessation of exposure, respectively. The total absorbed dose of dioxane during the 6 hr period was 5.4 ±1.1 mgjkg, although the maximum amount of dioxane in the body at any one time was 1.2 ± 0.2 mg/kg and occurred at the end of the exposure. At 6 hr the amount of dioxane in the body had reached over 99% of the steady-state amount. A simulation of repeated daily exposures to 50 ppm dioxane for 8 fir/day indicated that dioxane would never accumulate to concentrations above those attained after a single 8 hr exposure as long as the exposure concentration of dioxane was 50 ppm or less. Lack of accumulation of dioxane on repeated exposure is a critical point since saturation of the metabolism of dioxane at high dosage levels to rats has been shown to lead to toxicity. The results of the study conducted in human volunteers support the conclusion that exposure to the current threshold limit value of 50 ppm dioxane in the workplace will not cause adverse effects, even when the exposure is on a continuous or repeated basis.

Abstract  This paper presents a comparison of summer and winter levels of twenty-five selected volatile organic compounds (VOC) measured as part of the New Jersey project on Airborne Toxic Elements and Organic Substances (ATEOS). Most of the selected VOC were found in the range of 0.01–1.00 ppbv, with the exception of toluene (1–5 ppbv) and benzene (1–3 ppbv). However, peak levels of many compounds increased more than 100 fold during specific pollutant episodes. Generally, VOC levels were higher in the winter than the summer. Day to day variations of measured aromatic VOC showed significant correlations at each site suggesting an area source (motor vehicles), while there was little relationship between chlorinated species. During summer oxidant episodes, selected VOC increased from 2–10 times at Newark and Elizabeth, but not at Camden. In the winter, nocturnal temperature inversions caused levels of selected VOC to increase from 2–3 times seasonal average at all sites.

Abstract  (no abstract)

Abstract  Commercial Philippine fish sauce (Patis) was steam-distilled and the distillate was fractionated into four fractions, neutral, basic, acidic and phenolic and each fraction was analyzed using gas chromatography and gas chromatography-mass spectrometry. As a result of this study, a total of 66 compounds were identified in Patis, 14 of which were only a tentative identification. Out of these 66 identified compounds, 40 identified compounds have not been reported in previous studies on fish sauces. These identified compounds include 19 acids, 14 alcohols, 12 nitrogen containing compounds, 5 esters, 3 sulfur containing compounds, 1 phenol, 3 carbonyls, 7 hydrocarbons and 2 others. In the acidic fraction, 5 acids were considered major constituents which accounted for about 98% of the total acids. n-Butanoic acid was found to be the most abundant accounting for about 50% of the total acids.

Abstract  Common laundry products, used in washing and drying machines, can contribute to outdoor emissions through dryer vents. However, the types and amounts of chemicals emitted are largely unknown. To investigate these emissions, we analyzed the volatile organic compounds (VOCs) both in the headspace of fragranced laundry products and in the air emitted from dryer vents during use of these products. In a controlled study of washing and drying laundry, we sampled emissions from two residential dryer vents during the use of no products, fragranced detergent, and fragranced detergent plus fragranced dryer sheet. Our analyses found more than 25 VOCs emitted from dryer vents, with the highest concentrations of acetaldehyde, acetone, and ethanol. Seven of these VOCs are classified as hazardous air pollutants (HAPs) and two as carcinogenic HAPs (acetaldehyde and benzene) with no safe exposure level, according to the US Environmental Protection Agency. As context for significance, the acetaldehyde emissions during use of one brand of laundry detergent would represent 3% of total acetaldehyde emissions from automobiles in the study area. Our study points to the need for additional research on this source of emissions and the potential impacts on human and environmental health.

Abstract  Flavor is an important quality attribute which relates to the organoleptic characteristics of meat. Although perception of flavor is a complex phenomenon, odor is the most important single factor contributing to the overall characteristics of flavor. A large number of compounds have been identified in the volatile fraction of red meats and poultry. An overview of the chemical constituents present in the volatiles of beef, pork, mutton, and chicken is presented according to species and arranged by chemical class--hydrocarbons, alcohols, acids, aldehydes, ketones, sulfides, heterocyclic compounds, etc. The volatile components of cured and uncured pork are compared. The field of meat flavor is assessed in terms of what has been accomplished and the direction in which it may proceed. Techniques for analysis of these volatiles are briefly described.