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A direct, fast and sensitive LC–MS/MS method was developed to measure biomarkers for mycotoxin exposure in human urine. In total, 32 biomarkers were quantitatively or semi-quantitatively measured in 32 urine samples of Belgian volunteers using two injections. All urine samples contained deoxynivalenol-15-glucuronide, the major detoxification metabolite of deoxynivalenol, in the ng/mL range. Also deoxynivalenol-3-glucuronide and de-epoxy-deoxynivalenol-glucuronide were present in, respectively, 90 and 25 % of the samples, while deoxynivalenol was detected in 60 % of the samples, in lower concentrations. Deoxynivalenol glucuronides were the major biomarkers for deoxynivalenol exposure. Ochratoxin A was detected in 70 % of the samples in pg/mL. Citrinin and/or dihydrocitrinone were detected in 90 % of the samples, also in concentrations of pg/mL. The presence of ochratoxin A and citrinin was confirmed by a second method using sample cleanup by immunoaffinity columns, followed by LC–MS/MS. Our data show that humans are much more exposed to citrinin than realized before and suggest further work on citrinin exposure in relation with ochratoxin A exposure, as both mycotoxins are nephrotoxic.

Two methods of application of pesticides viz. (i) application of the chemical (carbofuran or furathiocarb, a carbofuran precursor) on seeds; and (ii) soil application of encapsulated formulations (Ca2+-, Al3+- and Fe3+ alginate beads) of carbofuran were evaluated for their abilities to cope with practical problems resulting from the accelerated degradation of carbofuran in adapted soils. In previously-untreated soil, the half-life of carbofuran applied as the pure compound, the commercial microgranule formulation and the encapsulated formulation, was 8 weeks or more under standardized conditions (18-22 degrees C; 80% of the soil water retention capacity). The half-life of the carbofuran applied on seeds was only 2 weeks in this soil. In the previously-treated soil, the half-life of the pure active ingredient of carbofuran was 3 weeks with some of the encapsulated formulations such as alginate-Fe3+ beads and alginate-Ca2+ beads co-formulated with the fungicide TMTD. There was some evidence that degradation occurred only after the active ingredient had diffused out of the beads. The persistence of furathiocarb and carbofuran applied on seeds was < 5 days for all the seed treatments tested in the previously-untreated soil. Encapsulated chemicals in alginate beads were more promising than seed treatment in increasing their persistence in soils showing accelerated degradation. It is, however, necessary to check whether these kinds of formulations are still effective with respect to their insecticidal activity. (C) 1997 Elsevier Science Ltd.