Search

Beeswax is known for its ability to retain pesticides for a long time, and the progressive accumulation of pesticides in wax has had adverse health effects on bees. This study aimed to determine the residue levels of pesticides in Brazilian beeswax and assess the health risk to bees due to exposure to these pesticides using hazard quotient calculation. Nineteen samples collected from different regions from São Paulo State, Brazil, were analyzed for the presence of 160 compounds, including 17 metabolites. A modified QuEChERS approach was used for sample preparation followed by gas chromatography-tandem mass spectrometry (GC/MS-MS) analysis. The method validation parameters followed the requirements established by the EU SANTE 11813/2017 guideline. In 90% of the samples, one or more pesticide residues were found; among them, the most frequently found pesticides were chlorpyrifos and permethrin, which were present in 74% and 79% of the samples and had maximum levels of 18.6 ng g−1 and 72 ng g−1, respectively. The hazard quotient estimate was determined considering the acute lethal dose (LD50) per contact for each pesticide residue in beeswaxes. Thus, it has been shown that exposure to chlorpyrifos and permethrin represents an elevated risk for the health of bees. [ABSTRACT FROM AUTHOR]

The therapeutic efficacy of different doses of albendazole (ABZ) in the treatment of infection by acanthocephalan (Neoechinorhynchus buttnerae) in tambaqui (Colossoma macropomum) was evaluated. The bioaccumulation of ABZ and its main metabolites in the target tissue (muscle plus skin in natural proportions) was also evaluated. The fish received a daily dose of 10, 20 or 30 mg ABZ kg−1 bw via medicated feed for 34 days. Incorporation of ABZ in the fish feed was performed by coating with ethyl cellulose (EC) (0.75% w/w). The quantitation of ABZ residues and its metabolites in the target tissue was done using a validated ultra‐high performance liquid chromatography‐tandem mass spectrometry (UHPLC‐MS/MS) analytical method. In relation with the therapeutic efficacy, no statistically difference was found between the treated groups. The total residue (sum of ABZ residues and its metabolites) in the target tissue at steady‐state was significantly higher for the high dose. Biomagnification factors in all treatments were of low values, indicating that ABZ and its metabolites do not offer the risk of bioaccumulation in the target tissue. Thus, ABZ dose of 10 mg kg−1 bw is recommend. However, the effect of feed coating on treatment effectiveness and bioaccumulation of albendazole relative to an uncoated feed, and joint therapeutic studies of ABZ with anthelmintic natural products are recommended to be conducted. [ABSTRACT FROM AUTHOR]

This study provides the first data related to albendazole (ABZ) and its main metabolites [albendazole sulphoxide (ABZSO), albendazole sulphone (ABZSO2), and albendazole-2-amino sulphone (ABZ-2-NH2-SO2)] residue depletion in tambaqui (Colossoma macropomum) parasitised by acanthocephalan (Neoechinorhynchus buttnerae). The ABZ withdrawal period was also calculated. The fish received a daily dose of 10 mg ABZ kg−1 body weight (b.w.) via medicated feed for 34 days. Samples of target tissue (muscle plus skin in natural proportions) were collected 24, 48, 72, 120, 168, 240, and 336 h after the end of ABZ administration. The quantitation of ABZ residues and its metabolites in the target tissue was performed using a validated ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) analytical method. After treatment, ABZ in the target tissue was rapidly metabolised over time, and ABZSO was the most persistent metabolite and was shown to be at the highest levels in the target tissue. Considering the maximum residue limit (MRL) established by Codex Alimentarius in the muscle (100 μg kg−1, species not specified), a withdrawal period of 4 days (112 °C-day) was estimated for the total residue (sum of ABZ and its metabolite residues). Considering data reported in the literature and data obtained in this study, it is suggested that the total residue be considered as marker residue to be adopted for fish in the legislative framework. [ABSTRACT FROM AUTHOR]

The influence of fish burger preparation and frying on residual levels of enrofloxacin (ENR) and ciprofloxacin (CIP) was evaluated. For this purpose, a high-throughput liquid chromatography-mass spectrometry analytical method for the quantitation of ENR and CIP residues in tilapia products (fillet, raw fish burger and fried fish burger) was developed and validated based on European and Brazilian guidelines. Sample preparation was accomplished by extraction with acidified acetonitrile followed by clean-up with hexane. Chromatographic analysis was performed on a C18 column using isocratic elution with 0.1% formic acid and acetonitrile (85:15 v:v). The analytical method showed suitable performance to quantify the residual levels of ENR and CIP in the studied matrices. No reduction in the residual levels of ENR and CIP was observed during fish burger preparation and only a 10% reduction occurred as a consequence of frying, indicating that both compounds were stable to the preparation of the fish burger and to frying conditions. [ABSTRACT FROM AUTHOR]