A simple method for the determination of carbaryl and 1-naphthol in fruit juices by high-performance liquid chromatography-diode-array detection

Phytoextraction Potential of Sunn Hemp, Sunflower, and Marigold for Carbaryl Contamination: Hydroponic Experiment

The phytoextraction ability and responses of sunn hemp, sunflower, and marigold plants were investigated toward carbaryl insecticide at 10 mg L-1 and its degradative product (1-naphthol). All test plants exhibited significant carbaryl removal capability (65-93%) with different mechanisms. Marigold had the highest translocation factor, with carbaryl taken up, translocated and accumulated in the shoots, where it was biotransformed into 1-naphthol. Consequently, marigold had the least observable toxicity symptoms caused by carbaryl and the highest bioconcentration factor (1848), indicating its hyperaccumulating capability. Sunflower responded to carbaryl exposure differently, with the highest carbaryl accumulation (8.7 mg kg-1) in roots within 4 days of cultivation, leading to a partial toxicity effect. Sunn hemp exhibited severe toxicity, having the highest carbaryl accumulation (91.7 mg kg-1) that was biotransformed to 1-naphthol in the sunn hemp shoots. In addition, the different models were discussed on plant hormone formation in response to carbaryl exposure.

Oxygenated polycyclic aromatic hydrocarbons in mussels: analytical method development and occurrence in the Belgian coastal zone

An analytical method was developed for the trace quantification of oxygenated polycyclic aromatic hydrocarbons (oxyPAHs) in mussels. Compounds included were naphthalene-1-ol, 9H-fluoren-9-one, anthracene-9,10-dione, 7H-benz[de]anthracene-7-one, naphtacene-5,12-dione, and benzo[a]anthracene-7,12-dione. Pyrene-1-carboxaldehyde was applied as an internal standard. Sample extraction by pressurized liquid extraction was followed by cleanup on silica, separation by high performance liquid chromatography, and quantitative measurement by mass spectrometry with atmospheric pressure chemical ionization. The method was validated by the analysis of spiked mussel samples, resulting in trueness values of 90-124% and measurement uncertainties of 6-49%, except for naphthalene-1-ol. Quantification limits varied from 0.25 ng·g^-1 to 10.7 ng·g^-1. The developed analytical oxyPAH method was applied on mussel samples from groynes and quaysides along the Belgian coastline and oxyPAH data were compared to PAH concentration data. The sum of 14 US EPA priority PAHs reached maxima at the eastern side of the Belgian coastal zone, with on average 202 ng·g^-1 wet weight for quayside Zeebrugge and 38.4 ng·g^-1 wet weight for groyne Knokke mussels. Anthracene-9,10-dione concentrations reached maxima of 19.1 ng·g^-1 wet weight at the most industrialized quayside of Zeebrugge. For other oxyPAHs, no clear relationship could be made with direct PAH emissions. Concentrations of anthracene-9,10-dione and 9H-fluoren-9-one were found to exceed corresponding parent PAH concentrations.

Micellar liquid chromatographic determination of carbaryl and 1-naphthol in water, soil, and vegetables

A liquid chromatographic procedure has been developed for the determination of carbaryl, a phenyl-N-methylcarbamate, and its main metabolite 1-naphthol, using a C18 column (250 mm  ×  4.6 mm) with a micellar mobile phase and fluorescence detection at maximum excitation/emission wavelengths of 225/333 nm, respectively. In the optimization step, surfactants sodium dodecyl sulphate (SDS), Brij-35 and N-cetylpyridinium chloride monohydrate, and organic solvents propanol, butanol, and pentanol were considered. The selected mobile phase was 0.15 M SDS-6% (v/v)-pentanol-0.01 M NaH₂PO₄ buffered at pH 3. Validation studies, according to the ICH Tripartite Guideline, included linearity (r > 0.999), limit of detection (5 and 18 ng mL⁻¹, for carbaryl and 1-naphthol, resp.), and limit of quantification (15 and 50 ng mL⁻¹, for carbaryl and 1-naphthol, resp.), with intra- and interday precisions below 1%, and robustness parameters below 3%. The results show that the procedure was adequate for the routine analysis of these two compounds in water, soil, and vegetables samples.

High-performance liquid chromatography multiresidue method for the determination of N-methyl carbamates in fruit and vegetable juices

A rapid multiresidue method has been developed for the analysis of N-methylcarbamate insecticides (oxamyl, methomyl, propoxur, carbofuran, carbaryl, and methiocarb) in fruit and vegetable juices. The method is based on the adsorption of the N-methyl carbamates in Florisil and the subsequent extraction of pesticides using a low volume of acetone. Residue levels in juice were determined by reversed-phase high-performance liquid chromatography with fluorescence detection after postcolumn derivatization. The separation of carbamates is performed on a C8 column with water-methanol as mobile phase. Recovery studies were performed at 500-, 100-, and 10-ng/ml fortification levels, and average recoveries obtained for carbamates ranged from 79 to 109%, with relative standard deviations between 1.4 and 9.9%. The method was found to be linear over the range assayed from 10 to 1,000 ng/ml, and the detection limits for carbamates varied from 0.8 to 1.9 ng/ml.