Analytical Method for the Determination of Atrazine and Its Dealkylated Chlorotriazine Metabolites in Urine by Gas Chromatography/Mass Selective Detection

Spatiotemporal variations of 2,4-dichlorophenoxy acetic acid with the role of sugarcane industry and related human health risk assessments in the Shadegan International Wetland

2,4-Dichlorophenoxyacetic acid (2,4-D) is the most important pesticide widely used in Khuzestan province. This study aimed to determine the ecological risks assessment in fish, plant tissues, and trends in 2,4-D urinary biomarker concentration in humans of Shadegan International wetland, Iran. Sampling was carried out from three areas: freshwater, saltwater, and brackish water. The average concentration of 2,4-D at point 38, taken from the wetland's northern parts, was 15.73 µg/L. In the lower regions, it reached 326 µg/L at point 25. From points 37 to 16, it was higher than the international standard. The increasing trend of 2,4-D concentration was observed from point 36 to the middle of the wetland. The non-carcinogenic risk through ingestion and skin contact for children and adults was 3E-3 and 1.5E-2, 2.1E-3, and 8.6E-5, respectively, and through fish, consumption was 7.1E-4 for both groups. HI values were below one (< 1), indicating no health risk. HQ values in the summer were more than one (> 1), indicating the high risk to aquatic organisms and human health.

Determination of atrazine and its metabolites in mouse urine and plasma by LC–MS analysis

Atrazine is a herbicide widely used on agricultural commodities. Existing analytical methods to analyze atrazine and its metabolites in biological matrices have various drawbacks. Thus, further development of such methods will be needed to correlate the growing number of toxicological effects associated with atrazine exposure with the concentrations of this compound and its metabolites in plasma, urine, and tissues. The purpose of this study was to develop a broad and sensitive LC-MS method for the analysis of atrazine and its metabolites in mouse urine and plasma. We were able to simultaneously measure atrazine and its major mammalian metabolites, which include didealkyl atrazine, desisopropyl atrazine, desethyl atrazine, atrazine-glutathione conjugate, and atrazine-mercapturate, using preparation procedures that used small sample volumes of plasma and urine (0.25 and 0.5 ml, respectively). Furthermore, derivatization of analytes prior to analysis was unnecessary. This method was used to analyze plasma and urine samples following single in vivo oral exposures of a limited number of mice to atrazine (doses, 5-250 mg/kg body weight) to demonstrate the utility of this LC-MS method. The data obtained from this study suggest that atrazine is rapidly metabolized in mice. Didealkyl atrazine was the most abundant metabolite detected in the urine and plasma samples (approximately 1000 microM in 24-h urine and approximately 100 microM in plasma following the highest dose of atrazine), with lesser quantities of mono N-dealkylated metabolites and thio conjugates of atrazine observed. We also used this methodology in a preliminary study of cytochrome P450-catalyzed metabolism of atrazine in vitro. The results obtained in this study suggest that this method will be a useful tool for the determination of atrazine and its metabolites in future pharmacokinetic studies and for the subsequent development and refinement of biologically based models of atrazine disposition.

Solid-phase extraction with styrene-divinylbenzene sorbent for high-performance liquid or gas chromatographic determination of urinary chloro- and methylthiotriazines

A solid-phase extraction (SPE) procedure on a styrene-divinylbenzene (SDB-1 cartridge) for extraction and cleaning of the triazine herbicides atrazine, simazine, ametryn, and prometryn and atrazine monodealkylated metabolites from urine samples was developed and optimised for final high-performance liquid chromatographic (HPLC-UV diode array detection) and gas chromatographic (GC-electron-capture detection and GC-thermionic-sensitive detection) analyses. Interfering polar matrices were eliminated by rinsing SDB-1 with 1% acetonitrile in water or with pure water. Extraction recoveries were from 78 to 101% with an RSD of about 10% for all studied compounds. The extraction recovery for the didealkylated atrazine metabolite was significantly lower and this compound cannot be determined with these procedures. Sorbent matrix generated interferences, although not detected by the chromatographic system, lowered the response of nitrogen-phosphorus and electron-capture GC detectors for monodealkylated chlorotriazines when compared to standards prepared in n-hexane. HPLC and GC analysis with SPE (SDB-1) preconcentration showed excellent linearity over the concentration range tested, with detection limits in urine of 10 ng ml(-1) for the parent herbicides (HPLC and GC analysis) and 20 ng ml(-1) for monodealkylated chlorotriazines (HPLC analysis).

Determination of sulfonic acid degradates of chloroacetanilide and chloroacetamide herbicides in groundwater by LC/MS/MS

An analytical method is presented which permits qualitative and quantitative analysis of sulfonic acid degradates of three chloroacetanilide herbicides (acetochlor, alachlor, and metolachlor) and one chloroacetamide herbicide (dimethenamid) in groundwater at trace levels with determination by LC/MS/MS. The analytes were isolated from groundwater by solid-phase extraction (SPE). The final samples were analyzed by reversed-phase HPLC with MS/MS detection utilizing a pneumatically assisted, and heat-assisted electrospray interface (TurboIonSpray). Unique precursor/production pairs were obtained in the MS/MS mode which permitted conclusive identification of each analyte, even when the analytes coeluted. Quantification was performed by generation of an external calibration curve. Excellent linearity was obtained over a calibration range from 0.25 to 10 ng injected on-column, with all linear correlation coefficients exceeding 0.999. Method performance for this analytical procedure was validated by analyzing groundwater samples fortified at levels of 0.1, 1, and 50 ppb. The average recovery at each fortification level for each analyte exceeded 89%. Excellent method precision was demonstrated with percent relative standard deviations of less than 10% for all analytes at all fortification levels.