Ion-chromatographic screening method for monitoring arsenate and other anionic pollutants in ground waters of Northern Italy.

A novel, rapid ion-chromatographic method for screening anionic pollutants in ground water, based on both conductivity and postcolumn spectrophotometric detection, has been developed. A relatively rapid separation of more than ten inorganic and polarizable anions was achieved by coupling an high capacity, hydroxide selective anion-exchange columns (Dionex IonPac AS16) supplied with an electrolytic eluent generator operating in gradient mode. The good control of the selectivity allowed the determination of polarizable anions including arsenate, thiocyanate, thiosulfate and perchlorate without interference from major components present at levels greater than 100 mg l(-1). This method was applied to the determination of arsenate in ground water samples collected in industrial and agricultural zones of Lombardia (Northern Italy). No traces of arsenate were detected in any sample, but added arsenate cannot be revealed by chromatographic analyses. This fact can be attributed to different causes, from reduction to the more reduced arsenic form to precipitation or dissolution in organic or inorganic based colloids. Oxidation with hydrogen peroxide seems to be useful for a partial recovery of added arsenate, but a stronger oxidation method, compatible with chromatographic separation, must be studied.

Use of ion chromatography for monitoring microbial spoilage in the fruit juice industry.

Fruit juices and purees are defined as fermentable, but unfermented, products obtained by mechanical processing of fresh fruits. The presence of undesired metabolites derived from microbial growth can arise from the use of unsuitable fruit or from defects in the production line or subsequent contamination. This involves a loss in the overall quality that cannot be resolved by thermal treatment following the start of fermentation. With these considerations, together with microbiological control, the analysis of different metabolites, which can be considered as microbial growth markers, such as alcohols (i.e. ethanol, etc.), acids (i.e. acetic, fumaric, lactic, etc.) is fundamental in order to achieve a better evaluation of product quality. Enzymatic determination and other single-component analytical techniques are often used for the determination of these metabolites. When the microbial spoilage is not well known, this results in a long and cumbersome procedure. A versatile technique that is capable of determining many metabolites in one analysis could be helpful in improving routine quality control. For this purpose, an ion chromatographic technique, such as ion exclusion, for separation, and diode array spectrophotometry and conductivity, for detection, were evaluated. Both different industrial samples and inoculated samples were analyzed.

Determination of denzimol, a new anticonvulsant agent, and its main metabolite in biological material by gas chromatography and high-performance liquid chromatography.

Two methods, using gas chromatography (GC) and high-performance liquid chromatography (HPLC), were developed in order to investigate the pharmacokinetics of denzimol hydrochloride, N-[beta-[4-(beta-phenylethyl)phenyl]-beta-hydroxyethyl] imidazole hydrochloride, which is a new anticonvulsant drug, and of its main metabolite, N-[beta-[4-(beta-phenyl-beta(alpha)-hydroxyethyl)phenyl] -beta-hydroxyethyl]-imidazole (referred to as M2), in humans. Both methods involve the use of a homologue of denzimol as an internal standard. The GC method is more sensitive (sensitivity limit 2.5 ng/ml for denzimol and 15 ng/ml for M2) and was utilized for the determination of denzimol and M2 in plasma. The GC method is specific, precise (relative standard deviations are 3.26, 2.12 and 1.72% at 10, 100 and 1000 ng/ml for denzimol and 6.45, 4.17 and 3.38% at 50, 500 and 1000 ng/ml for M2) and accurate (mean recovery +/- S.D. is 102.58 +/- 4.10% for denzimol and 99.72 +/- 7.75% for M2). The HPLC method is very simple and quick to perform. This method has a sensitivity limit of 0.5 micrograms/ml for denzimol and 1 microgram/ml for M2, and allows the determination of both compounds in urine with high selectivity, reproducibility (relative standard deviations are 2.05, 3.50 and 1.02% for denzimol and 2.78, 2.80 and 1.73% for M2, at concentrations of 15, 35 and 70 micrograms/ml) and accuracy (mean recovery +/- S.D. is 103.57 +/- 2.97% for denzimol and 95.91 +/- 1.59% for M2). The common anticonvulsants, when present in plasma, do not interfere with the monitoring of denzimol levels.

Fenticonazole tissue levels after the application of 3 different dosage forms of vaginal ovules.

Fenticonazole vaginal ovules of 200 mg, 600 mg and 1,000 mg were administered to 42 women prior to gynecological surgery. Tissue concentrations in the vaginal mucosa were determined after 3 h and 12 h in biopsy specimens taken from the same position in the posterior fornix. Tissue concentrations were higher at 3 h in comparison to 12 h with all 3 doses. There was no statistical difference between the concentrations yielded by the 3 different ovules at 3 h, while after 12 h the concentrations were dose-dependent and significantly higher after 1,000 mg in comparison to 200 mg, but not to 600 mg.