In this study we have determined the morphological, some physiological and biochemical characteristics of a fungal strain isolated from balsamic and cider vinegars. The examination of fungal contamination of 100 balsamic and cider vinegar samples showed that 90% contained more than 104 colony forming units (CFU ml−1), but in most samples (65%) values of more than 105 CFU ml−1 were obtained. The most frequent contamination was with Monascus sp. (80% of the samples examined showed 2 × 103 to 6 × 105 CFU ml−1). This mould can produce secondary metabolites such as citrinin and monacolin KL (lactone form), and monacolin KA (acid form). Using high-performance liquid chromatography (HPLC) with fluorescence detection, citrinin was found in 68% of the samples. The concentration of these mycotoxins varied between 1.6 × 10−2 µg ml−1 and 7.2 × 10−2 µg ml−1. The concentrations of citrinin were very low, and we can anticipate that this compound at these concentrations has no toxic effects on renal cells. Monacolin was not detected in any sample studied.

The recent developments in liquid chromatography (LC) are mainly dedicated to both system miniaturization (micro-, capillary-, and nano-LC) and analysis time decrease (fast-, and ultra-fast-LC). For the latter, several strategies can be used, and high temperature liquid chromatography (HTLC) seems very promising and easy to implement, especially in miniaturized system. In LC, the evaporative light scattering detector (ELSD) is considered an attractive alternative to conventional detector such as UV–vis due to its versatility and quasi-universality. Therefore, the compatibility of ELSD with μ-LC and μ-HTLC was investigated for several pharmaceutical compounds of interest. The nebulization process appeared to be the most critical parameter for performing the coupling and maintaining an efficient separation. Therefore, appropriate modifications in the nebulization cell geometry were brought to make ELSD fully compatible with μ-LC. The impact of optimized nebulization cell on chromatographic performance was evaluated in terms of efficiency and sensitivity. Finally, highly efficient, sensitive and fast separations of pharmaceutical drugs were performed with both techniques and the customized nebulization cell design.

A heart-cutting liquid chromatography-mass spectrometry (LC-MS) method was developed for the simultaneous analysis of seven process related substances (PRS) at ng ml(-1) level in tablets containing cetirizine (CTZ) as active ingredient. After dissolution and filtration, 10 mul of sample was injected onto a cyano-column coupled to an electrospray ionization-mass spectrometer (ESI-MS) equipped with a single quadrupole. A switching valve placed between the analytical column and the MS detector allowed for the transfer of only the PRS fractions into the MS. The separation of PRS and CTZ was achieved in <14 min with a binary gradient using a 50 mM ammonium acetate solution (pH 7) and acetonitrile. The ESI-MS detection was performed using single ion monitoring (SIM).The method was validated. Weighted linear regression was found appropriate in a concentration range of 2.5-250 ng ml(-1) and the limit of quantification (LOQ) was estimated at 10 ng ml(-1) for each analyte. Method selectivity and robustness was demonstrated. Method performance was evaluated in terms of accuracy and precision using quality control (QC) samples over the investigated range. Finally, the heart-cutting LC-MS method was successfully applied to commercially available tablets. (C) 2003 Elsevier Science B.V. All rights reserved.