Reversed phase liquid chromatography trace analysis of pesticides in soil by on‐column sample pumping large volume injection and UV detection

Abstract

The idea of utilization of one hydraulic line of a common commercial HPLC pump for direct on-column sample pumping injection of large sample volumes, 20 mL, was further investigated with the aim to develop multicomponent pesticides trace residues HPLC method in gram soil samples. Target pesticides group involve asulam, atrazine, 2,4-D, PCA, propazine, simazine, 4-chloro-2-methylphenoxyacetic acid, 2-(4-chloro-2-tolyloxy) propionic acid, chlortoluron, metoxuron, epoxiconazole. The results proved the applicability of this approach in experiments with mixtures of analytes at low ng/mL levels. Analysis of 20 mL of soil leachates and extracts of fortified soil samples containing these pesticides at the 10-50 ng/g level (in dry soil) revealed good figures of merit, also in the presence of large excess of humics. LODs achieved by detection at 220 nm evaluated from calibration runs of spiked soil extracts by Hubaux et al. method ranged from 5-12 ng per injected volume. For 20 mL large volume injection it represents 0.25-0.6 ng/mL of diluted soil extract, or 2.5-6 ng/mL of crude extract, or 6-5 ng/g dry soil. Recoveries of pesticides at concentration levels approaching half of maximum allowable concentration of pesticides in soil (100 ng/g) ranged from 85 to 98% with acceptable reproducibility, except asulam and metoxuron.

An on-line SPE–HPLC method for effective sample preconcentration and determination of fenoxycarb and cis, trans-permethrin in surface waters

“…The Water Framework Directive (2000/60/EC) established a maximum allowed concentration of 0.1 g L À 1 for each individual pesticide and 0.5 g L À 1 for the sum of pesticides [3]. Therefore, it is necessary to study the distribution of these compounds and the monitoring of trace levels in different environmental matrices because these compounds can produce negative health effects and show negative influence on ecosystems and fauna [4,5]. In this sense, it is necessary to develop reliable, sensitive and efficient techniques for the analysis of trace concentrations of organic pollutants in environmental samples.…”

Carboxylated carbon nanotubes as an efficient and cost-effective adsorbent for sustainable removal of insecticide fenvalerate from contaminated solutions

“…Hence, providing clean water and a clean environment for people is the most important matter [1]. Over the last 30 years, synthetic pyrethroids, such as fenvalerate, cyfluthrin, and deltamethrin, have been widely used as agricultural, home insecticides to replace the more toxic and environmentally persistent organochlorine and organophosphorous pesticide.…”

LC-MS/MS method for simultaneous determination of myclobutanil, hexaconazole, diniconazole, epoxiconazole and tetraconazole enantiomers in soil and earthworms

“…Previous studies also showed that (+)-tebuconazole was accumulated from soil to earthworms with a biota to soil accumulation factor (BASF) of 1.64, whereas (-)-tebuconazole did not accumulate in earthworms [11]. Several studies have focused on the determination of triazoles in soil [12][13][14][15]. Furthermore, a number of technologies, such as high-performance liquid chromatography (HPLC) [16][17][18][19][20], gas chromatography, capillary electrophoresis (CE) [21][22][23], supercritical fluid chromatography (SFC) [24], thin layer chromatography (TLC), simulated moving bed chromatography (SMBC), countercurrent chromatography and microtechnology have been introduced in enantiomers' analysis [25,26].…”