Rapid multi-residue method for the determination of pesticide residues in human serum

Exposure to pesticides can represent a potential risk to humans. Agricultural workers are at risk of chronic toxicity. Hence, the evaluation of pesticide residues in their blood gives an indication about the extent of exposure and help in assessing adverse health effects. The aim of our study was to develop analytical method for the simultaneous determination of some residues of pesticides using gas chromatography-mass spectrometry (GC-MS). This method involves a liquid-liquid extraction procedure. Pesticide residues were separated and detected using GC-MS, and acquisition was performed in the sellected ion monitoring (SIM) mode. For most of the pesticides, average recoveries ranged between 65 and 101% at three different fortification levels. The linearity of the method was satisfactory in the range of 5 to 50 ng/ml, with a correlation coefficient between 0.998 and 0.999, depending on the analyte. The estimated limit of detection and limit of quantification ranged from 2 to 5 ng/ml and from 5 to 10 ng/ml, respectively. The method precision and accuracy were found to be satisfactory at three concentration levels. The variation coefficients of intra-day and inter-day precision ranged from 0.4 to 14% and from 2.5 to 15%, respectively for most studied pesticides.Keywords: Analytical methods, human serum, GC-MS, pesticide residues, validatio

Lower paraoxonase 1 activity in Tunisian bipolar I patients

Abstract Background The purpose of this study was to investigate the variations of paraoxonase activity and lipid profile in bipolar I patients, and the association of this activity with the sociodemographic, clinical and therapeutic characteristics of this population. Patients and methods Our study included 66 patients with bipolar I disorder and 64 controls aged 37.9 ± 12.6 and 36.3 ± 18.2 years, respectively. Paraoxonase activity was determined by kinetic methods; high-density lipoprotein cholesterol (c-HDL), low-density lipoprotein cholesterol (c-LDL), triglycerides and total cholesterol were determined by enzymatic methods; apolipoprotein (Apo)A1, ApoB and lipoprotein (a) (Lp(a)) were determined by immunoturbidimetry using Konelab 30 equipment (Thermo Scientific). Results Compared with controls, patients had a significantly lower paraoxonase activity and ApoA1 level, and significantly higher total cholesterol, c-LDL and Lp(a) level and ApoB/ApoA1 ratio. Furthermore, paraoxonase activity was significantly correlated with c-HDL values (r = 0.5612; P Conclusions Bipolar patients had a significant decrease in paraoxonase activity and perturbations in their lipid profile that contribute to increased risk of cardiovascular diseases. Decrease in this activity was significantly associated with treatment with lithium but not with sociodemographic and clinical characteristics. Therefore, such patients require specific care, particularly with regard to their lipid profile.</p

Biomonitoring chronic lead exposure among battery manufacturing workers in Tunisia

International audienc