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Airborne dust samples from damp (n = 9) and control (n = 9) residences were analyzed for microorganisms (molds and bacteria), bacterial markers (3-hydroxy fatty acids and muramic acid), and adsorbed volatile organic compounds (VOCs). The number of mold species was greater in the damp residences than in the controls (23 vs.18) and nine mold species were found only in damp residences. The levels of 3-hydroxy fatty acids and muramic acid correlated better in damp residences than in controls, indicating that damp conditions affect the bacterial flora of airborne dust. Identifications made by culture and microscopy of the major molds found, i.e. Aspergillus, Cladosporium, and Penicillum, coincided with the identification of VOCs known to be produced by these species. A number of additional VOCs irritating to the skin, eyes, or respiratory tract were also found. The results from this pilot study illustrate the diversity of microorganisms and VOCs present in the indoor environment and suggest that analysis of airborne dust may help to assess human exposure to microorganisms and chemical compounds.

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A GC-UV instrumental set up with two different GC units has been used for determination of specific functional groups and compounds in complex mixtures. Separations have been made using a micro gas chromatograph built into a gas flow cell and by means of an external capillary gas chromatograph linked to the same gas flow cell. Four various applications (cigarette smoke, petroleum, dust, flavour) have been performed in order to demonstrate the potential of the GC-UV method. Gas phase UV spectra have been recorded in the region of 168-330 nm. Based on a gas phase spectrum reference library the identification of unknowns as well as the determination of specific functional groups have been achieved. A table showing the spectral shapes and positions of the absorption bands for 50 specific functional groups is presented. The advantage of using derivative spectra in order to amplify spectral details and improve selectivity is discussed. Regarding sensitivity, it has been found that identifications can be made in the mid-pg range and limit of detection for naphthalenes are at a level of 0.5-3 pg/s.

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A new analytical method gas chromatography combined with UV spectrophotometry was used to measure isoprene and acetone in expired breath collected from four different groups of children: 1) healthy newborn babies, 2) healthy preschool children, 3) healthy school children, and 4) diabetic children in different metabolic states. Both isoprene and acetone could readily be determined in one single analysis of a 250-mL air sample. Newborn babies during the first postnatal week had undetectable or very low levels of isoprene in their expired air irrespective of catabolic or anabolic state. Breath isoprene increased with age, and healthy school children had higher levels than did healthy preschool children. No significant differences in breath isoprene were found between healthy and diabetic children. Breath acetone was found to correlate with metabolic state both in newborn babies and in diabetic children. These findings illustrate the potential use of a new technique for breath analysis in children with metabolic disturbances.

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A novel instrument, which combines gas chromatographic separation with ultraviolet detection, has been employed in the qualitative study of molecular UV absorption spectra in the gas phase. The wavelength range available with the current instrument made studies in the region of 168-330 nm possible. The absorption spectra between 168 and 330 nm for ∼1000 organic compounds and a number of inorganic gases were registered. For all the spectra recorded, 69% showed absorption maxima shorter than 190 nm, and as much as 87% shorter than 200 nm. This indicates the importance of the short UV wavelength region for analytical purposes. The results showed that each compound studied gave rise to unique absorption spectra. The influence of temperature on the shape of the spectra was studied in the range of 15-205 °C. A slight broadening effect on spectral absorption bands (0.3 nm) and the vibrational structure (maximally 1.4 nm) with increased temperature was observed. However, this effect was shown to have no influence on the analytical results. In the vast majority of cases, where structural isomers were investigated, there were clear differences between the recorded spectra. Compounds with the same functional group showed pronounced similarities. The influence of conjugation and various substituents could be demonstrated. A commercial computer program was used for a computer search of unknowns against the recorded reference spectra. This showed that the gas-phase UV spectra are very well defined and that a search always resulted in a very close agreement, even if concentrations and chromatographic conditions were different between the recording of reference and unknown. When a search was performed on a compound not present in the library, the result pointed out the correct class of compounds.

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Nitric oxide (NO) has a number of important functions in biological systems and may play a role in the toxicity of mineral fibers. We investigated whether NO might be present on the surface of mineral fibers and if crocidolite could adsorb NO from NO gas or cigarette smoke. NO was determined with a new gas chromatography-ultraviolet spectrophotometric technique after thermal desorption from the fiber surface and injection in a gas flow cell. NO was found in different amounts on chrysotile B, crocidolite, amosite, and silicon carbide whiskers. There was a strong correlation between the amount of NO and the specific surface area of these fibers (r = 0.98). NO could not be demonstrated on rockwool fibers [man-made vitreous fiber(s) (MMVF)21 and MMVF22] or silicon nitride whiskers. NO on crocidolite, amosite, and silicon carbide whiskers was readily desorbed from the fibers at increased temperature, while NO on chrysotile B seemed to be more firmly adsorbed to the fiber and required a longer period of time to be desorbed. The amount of NO bound to crocidolite increased from 34 micrograms/g fiber to 85 and 474 micrograms/g after exposing the fibers to cigarette smoke and NO gas, respectively. These findings indicate that a) NO adsorbs to fiber surfaces, b) some fibers adsorb more NO than others, c) some fibers adsorb NO more strongly than others, and d) the amounts of NO on fibers may be increased after exposure of the fiber to cigarette smoke or other sources of NO. The biological significance of NO on mineral fibers remains to be investigated.

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We describe a new, highly sensitive and specific method for the analysis of isoprene (2-methyl-1,3-butadiene) in human breath. A known volume of expired air (150 ml) was drawn through a solid sorbent material to capture trace organic substances, followed by thermal desorption at 200 degrees C and subsequent determination of isoprene by gas chromatography with diode-array ultraviolet detection. The calibration plot was linear (r = 0.99) over a wide range of breath isoprene concentrations (0-12 nmol/l), and levels down to 0.10 nmol/l were easily measurable. In sixteen healthy subjects (six men and ten women), all of whom were non-smokers, the mean, median and spread of breath isoprene concentrations were 3.73, 3.36 and 1.60-10.33 nmol/l, respectively. No statistically significant differences in the concentrations of breath isoprene were observed between the sexes. The mean (+/- S.D.) concentration of breath isoprene in nine consecutive tests with the same subject was 3.69 +/- 0.60 nmol/l, and the coefficient of variation was 16.3%. Much larger variations in exhaled isoprene were seen during the day and also between days when the same subject was tested repeatedly. The excretion patterns of isoprene in human breath can be investigated with high selectivity and sensitivity with this new analytical method.

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Nickel concentration in serum and whole blood as well as nickel excretion in urine was assayed at different time intervals before and after ingestion of nickel sulfate in eight healthy volunteers during a three days study. The peak level of nickel in blood was reached 2.5 hours after nickel ingestion and the maximal urinary excretion of nickel was during the first eight hours after ingestion. Great individual variations in nickel concentrations in blood and nickel excretion in urine were observed. Analysis of nickel in both urine and serum reflects ingestion of a soluble nickel salt, but urine seems to be most reliable to follow.

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We describe procedures for direct determination of lead and cadmium in blood and urine by flameless atomic absorption spectrophotometry. Before analysis, the samples are pre-ashed in microboats in an ordinary laboratory oven. In this way, many samples can be prepared and pre-ashed simultaneously. We find the procedures presented in this work to be rapid, accurate, and precise.

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Healthy volunteers without nickel hypersensitivity were given 5.6 mg nickel orally. The nickel concentration was assayed in urine, serum and sauna-provocated sweat from hands and trunk before and after nickel ingestion. The nickel concentration in serum increased in all subjects, and in most cases in urine, but not decisively in sweat.

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