We analyzed 79 bulk samples of moldy interior finishes from Finnish buildings with moisture problems for 17 mycotoxins, as well as for fungi that could be isolated using one medium and one set of growth conditions. We found the aflatoxin precursor, sterigmatocystin, in 24% of the samples and trichothecenes in 19% of the samples. Trichothecenes found included satratoxin G or H in five samples; diacetoxyscirpenol in five samples; and 3-acetyl-deoxynivalenol, deoxynivalenol, verrucarol, or T-2-tetraol in an additional five samples. Citrinine was found in three samples. Aspergillus versicolor was present in most sterigmatocystin-containing samples, and Stachybotrys spp. were present in the samples where satratoxins were found. In many cases, however, the presence of fungi thought to produce the mycotoxins was not correlated with the presence of the expected compounds. However, when mycotoxins were found, some toxigenic fungi usually were present, even if the species originally responsible for producing the mycotoxin was not isolated. We conclude that the identification and enumeration of fungal species present in bulk materials are important to verify the severity of mold damage but that chemical analyses are necessary if the goal is to establish the presence of mycotoxins in moldy materials.
Cellular fatty acids of 10 strains of lactic acid bacteria were analyzed. The purpose of this work was to find lactic acid bacteria with high lactobacillic acid contents. The bacteria studied were unable to synthesize oleic acid. Some strains did not synthesize lactobacillic acid, although all were able to form dihydrosterculic acid. Twenty-one to thirty-four percent of the fatty acid content of Lactobacillus fermentum and L. buchneri was lactobacillic acid, and these species were chosen for future studies of environmental factors affecting cyclopropane fatty acid synthesis.
Background: A method is described for the simultaneous analysis of nicotine and two of its major metabolites, cotinine and 3-hydroxycotinine, as well as for caffeine from urine samples. The method was developed to assess exposure of restaurant and hotel workers to environmental tobacco smoke.
Methods: The method includes sample pretreatment and reversed-phase HPLC separation with tandem mass spectrometric identification and quantification using electrospray ionization on a quadrupole ion trap mass analyzer. Sample pretreatment followed standard protocols, including addition of base before liquid-liquid partitioning against dichloromethane on a solid matrix, evaporation of the organic solvent using gaseous nitrogen, and transferring to HPLC vials using HPLC buffer. HPLC separation was run on-line with the electrospray ionization-tandem mass spectrometric detection.
Results: The detection limits of the procedure were in the 1 μg/L range, except for nicotine (10 μg/L of urine). Still lower detection limits can be achieved with larger sample volumes. Recoveries of the sample treatment varied from 99% (cotinine) to 78% (3-hydroxycotinine).
Conclusions: The method described is straightforward and not labor-intensive and, therefore, permits a high throughput of samples with excellent prospects for automation. The applicability of the method was demonstrated in a small-scale study on restaurant employees.
If 9 ng cotinine/mg((creatinine)) is considered as the level above which heavy exposure has occurred, then this level was exceeded by 14 (approximately 60%) subjects at least once during the work week. Nicotine metabolite concentrations in the urine increased during the work week in 80% of the subjects, and the increase was especially noticeable for subjects working in both pubs and nightclubs. The study indicates that measures to restrict ETS exposure in restaurants are needed.
A method is described for the simultaneous determination of common aflatoxins (G1, G2, B1, B2) and their precursor sterigmatocystin, and also citrinine and ochratoxin A. The method was applied to a building material matrix artificially contaminated with mycotoxin-producing fungi. The method includes extraction, sample pre-treatment and reversed-phase HPLC separation with tandem mass spectrometric identification and quantification using electrospray ionisation on a quadrupole ion trap mass analyser (ESI-MS-MS). Aqueous methanol was used in the initial extraction and solvent partitioning and solid phase extraction in the purification of samples. The HPLC separation was run on-line with the ESI-MS-MS detection. The limit of quantification of the procedure was 200 ng for all compounds. Recoveries of the sample pre-treatment varied from 28 to 99%. The average compound- and concentration-dependent accuracy and precision (RSD) were 21 and 113%, respectively. The method includes small sample volumes (approximately 1 g in 20 ml) and few, non-labour intensive, sample treatment steps. It should allow for a high throughput of samples with good prospects of automation.
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