Occurrence of micropollutants in the Yesilirmak River Basin, Turkey.

The European Water Framework Directive (WFD) (2000/60/EC) is the most visionary piece of European environmental legislation that aims to achieve good water status of both surface water and groundwater bodies. The Directive provides a fundamental basis for surface water monitoring activities in the European Member States. The objective of this study is to investigate the occurrence of micropollutants in the Yesilirmak River and to develop a cost-effective monitoring strategy based on spatiotemporal data. A 2-year seasonal monitoring program was conducted between 2016 and 2018, and the water samples were analyzed for 45 priority substances as defined by the WFD and 250 national river basin-specific pollutants. In the basin, 166 pollutants were quantified in at least one of the samples with individual concentrations ranging from 6 × 10-6µg/L to 100 mg/L. Fifty-four pollutants with a frequency of occurrence greater than 5% were selected for further evaluation. Based on statistical evaluation of the data, 20 pollutants were identified as the pollutants of primary concern. These 20 pollutants were grouped under three categories (metals, biocides, and industrial organic compounds) and their spatiotemporal distributions in the basin were assessed to establish a monitoring strategy specific to each pollutant category. The results of the study revealed that the common season for the monitoring of all pollutant categories was the spring. This study provides a generic methodology for the development of a cost-effective water quality monitoring strategy, which can be applicable for use in different basins and pollutant datasets.

Determination of grayanotoxins in honey by liquid chromatography tandem mass spectrometry using dilute-and-shoot sample preparation approach.

A simple and rugged method of analysis for grayanotoxins I and III in honey using liquid chromatography triple quadrupole mass spectrometry with electrospray ionization was developed. This paper describes the first LC-MS/MS method for the quantitation and confirmation of the grayanotoxins in honey using "dilute-and-shoot" sample preparation approach. Honey sample was diluted 10-fold in methanol-water (1:4 v/v) prior to analysis. Chromatographic separation was achieved on a reversed phase HPLC column using a water-methanol gradient with 0.1% acetic acid. The method was fully validated for quantitative purposes. Overall recoveries, selectivity, overall intraday and interday repeatability, decision limit, and detection capability of the analytes was determined. The matrix effects, ruggedness, and analyte stability in standards and samples were studied. Ten real honey samples were successfully analyzed using the developed method. All the samples were found to contain residues of GTXs ranging from 0.1 to 39 mg/kg.

A rapid and simple method for simultaneous determination of triphenylmethane dye residues in rainbow trouts by liquid chromatography-tandem mass spectrometry.

A rapid and simple LC-MS/MS method was developed and optimized for screening and confirmation of triphenylmethane dyes including malachite green (MG), leucomalachite green (LMG), crystal violet (CV), leucocrystal violet (LCV) and brilliant green (BG) in fish muscle with skin. Leucocrystal violet D6 (LCV-D6) and leucomalachite green-D5 (LMG D5) was used as internal standards. Sample preparation is a simple procedure based on solid-liquid extraction with acetonitrile containing 1% acetic acid, followed by centrifugation and evaporation of the supernatant. The residue was dissolved in acetonitrile with 0.1% acetic acid and centrifuged prior to LC-MS/MS analysis. Chromatographic separation of analytes was performed on an Inertsil ODS-4 C18 column with ammonium acetate buffer in acetonitrile gradient. The mass detection was performed on a triple-quadrupole tandem mass spectrometer by multiple reaction monitoring (MRM) mode via electrospray ionization (ESI+). The developed method was validated according to the criteria set in Commission Decision 2002/657/EC. The decision limit (CCα) was 0.43, 0.24, 0.33, 0.28 and 0.17µgkg(-1) for MG, LMG, CV, LCV and BG respectively. The detection capability (CCß) values obtained were 0.56, 0.31, 0.43, 0.37 and 0.22µgkg(-1), respectively. The precision of the method, expressed as relative standard deviation (RSD) values for the within-day and inter-day laboratory reproducibility, for MG, LMG, CV, LCV and BG at the four levels of fortification (0.3, 0.5, 1, and 2µgkg(-1)), was less than 16 and 19% respectively. Accuracy of the method was confirmed by successful participation of a proficiency test organized by FAPAS. The method has been used for the analysis of 208 fish samples of which seven samples were found to be non-compliant containing low residues of LMG and LCV.