RESUMO
Chocolate is widely consumed worldwide and its market grows every year, with emerging demands for new high-quality products. However, this product is susceptible to contamination with polycyclic aromatic hydrocarbons (PAHs), representing a risk for humans. In this study, a methodology for the evaluation of benzo[a]pyrene, benzo[a]anthracene, benzo[b]fluoranthene and chrysene in chocolate by high performance liquid chromatography was validated. The occurrence, dietary exposure, and health risks of 4 PAHs in 38 commercial chocolate samples was investigated. The methodology demonstrated adequate accuracy and precision, with recovery (95.25 %-108.12 %) and relative standard deviation (0.14 %-5.83 %). Benzo[a]pyrene and the ∑4 PAHs concentrations varied between 1.09 and 10.42 µg/kg and 8.38-41.58 µg/kg, respectively. The results of risk assessment suggest low potential health risk for chocolate consumers, considering the margin of exposure (MOE) and the incremental life cancer risk (ILCR) values.
Assuntos
Cacau , Chocolate , Hidrocarbonetos Policíclicos Aromáticos , Humanos , Benzo(a)pireno , BrasilRESUMO
A simple, sensitive and reproducible solid-phase extraction method using plastic cartridges containing a monolithic sorbent (m-SPE), coupled to reverse phase liquid chromatography analysis, aiming to determine fifteen polycyclic aromatic hydrocarbons in surface water samples, was developed. The sorbent was easily prepared through a thermal polymerization reaction by using a mixture of n-butyl methacrylate as non-polar monomer and ethylene glycol dimethacrylate as crosslinker contained in a typical Polypropylene syringe cartridge. The effect of different parameters (type of hydrophobic monomer, elution solvent, sample volume, sorbent amount and sorbent load capacity) on the extraction efficiency was optimized. The optimal conditions were achieved by using n-butyl methacrylate as monomer, tetrahydrofurane (THF) as solvent for sorbent cleaning, THF:acetone (1:1) as elution solvent, 25.00 mL of sample volume, 600 µL of the polymerization mixture and 60 µg L-1 as sample loading capacity. Finally, the sorbent charge capacity, the reusability of the cartridges and the extraction efficiency of the m-SPE monolith, as compared with a typical C8 cartridge, were evaluated. Under the optimized experimental conditions, enrichment factors were between 76 and 103, relative recovery factors from 78 to 103%, accuracy values in the range of 58 to 98%, and inter-batch reproducibility values from between 2 and 10%, were obtained. The limits of detection and quantification were obtained by two different procedures: the signal to noise (S/N) ratios (3 and 10, respectively) and the IUPAC convention. The lowest LOD and LOQ values, obtained with the S/N ratios, were between 0.02 and 1.00 µg L-1, respectively whereas with the IUPAC convention the values were between 0.07 and 5 µg L-1. Using this procedure, several PAHs could be detected in the surface water sample taken from a river stream located in La Plata city (Buenos Aires Province, Argentina).
Assuntos
Hidrocarbonetos Policíclicos Aromáticos , Poluentes Químicos da Água , Cromatografia Líquida de Alta Pressão , Limite de Detecção , Polímeros , Reprodutibilidade dos Testes , Extração em Fase Sólida , Solventes , ÁguaRESUMO
Chronic bacterial prostatitis treatment consists of broad-spectrum antibiotic therapy for long periods of time. Drug penetration into the prostate makes the treatment a challenged. Ciprofloxacin is one of the most prescribed drugs for this treatment. A liquid chromatography with fluorescence detection method was developed and validated for determining ciprofloxacin concentrations in two different matrices: plasma and prostate microdialysate. Ciprofloxacin was separated on a C18 column eluted with a mobile phase constituted of a mixture of 0.4% aqueous triethylamine:methanol:acetonitrile (75:15:10, v/v/v) and 0.4% aqueous triethylamine:acetonitrile (88:12, v/v) for microdialysate and plasma samples, respectively. Linearity was obtained over a concentration range of 5-1000 ng/mL (microdialysate) and 10-2000 ng/mL (plasma), with coefficients of determination ≥0.9956. Precision was determined from the analysis of six quality control samples and showed RSD values <11.1 and 7.4% for intra and inter-assay precision, respectively. The accuracy ranged from 85.6 to 114.3%. The method was applied to a preliminary pharmacokinetic study to investigate ciprofloxacin concentrations in prostate, sampled by microdialysis, and plasma after a 7 mg/kg intravenous dose to Wistar rats. The method showed high sensitivity using only protein precipitation as plasma sample clean-up and was successfully applied to investigate ciprofloxacin prostate penetration.