Biomonitoring of occupational exposure: Neutron activation determination of selected metals in the body tissues and fluids of workers manufacturing stainless steel vessels

Occupational exposure was examined for 20 workers dealing with welding, polishing, and assembling of stainless steel vessels. Instrumental neutron activation analysis was used for determination of selected elements in hair and nail, whereas urinary Cr and Mn, blood Mn and serum Cr were determined by radiochemical neutron activation analysis. Increased levels of Cr in hair, nails, serum and urine, Mo in hair, and Mn in blood were found in the exposed group compared to controls. Accuracy of the results was proven by analysis of reference materials and by comparison of element levels in controls with reference values for non-exposed persons.     

Suitability of ionic liquids as mobile‐phase additives in HPLC with fluorescence and UV detection for the determination of heterocyclic aromatic amines

The effects of several ionic liquids (ILs) as mobile‐phase additives in HPLC with fluorescence and UV–Vis detection for the determination of six heterocyclic aromatic amines were evaluated using two different C₁₈ stationary phases with moderate silanol activity. The studied ILs were 1‐butyl‐3‐methylimidazolium tetrafluoroborate, 1‐hexyl‐3‐methylimidazolium tetrafluoroborate and 1‐methyl‐3‐octylimidazolium tetrafluoroborate. The optical behaviour of heterocyclic aromatic amines in presence of ILs was studied and the silanol‐suppressing potency of ILs was evaluated for the two stationary phases studied. Several chromatographic parameters were evaluated in the presence or absence of ILs, or using triethylamine, the most common mobile‐phase additive. The best results were achieved using 1 mM 1‐butyl‐3‐methylimidazolium tetrafluoroborate as mobile‐phase additive and NovaPak^® column. In these conditions and with 18% of ACN in the mobile phase, analytical performance of the chromatographic methods using fluorescence and UV–Vis were evaluated, obtaining good precision in all cases (RSD lower than 6.6%) and low LOD (0.001–0.147 μg/mL with UV–Vis and 0.001–0.006 ng/mL with fluorescence detection).