Comparison of different sample pre‐treatments for multi‐residue analysis of organochlorine and pyrethroid pesticides in chrysanthemum by gas chromatography with electron capture detection

Abstract

The widespread use of insecticides in Chinese herbal medicines has created a compelling need for the development of a multiresidue analytical method to help assure herbs safety. The operating variables affecting the performance of the multiresidue analysis of 34 organochlorine and 12 pyrethroid pesticides in chrysanthemum, a widely used kind of Chinese herbal medicines, were evaluated. Three different extraction solvents including n-hexane and its mixtures with acetone and petroleum ether were compared, and n-hexane was found to be an appropriate option. A combination of gel permeation chromatography and SPE was selected as the optimum cleanup, in comparison with dispersive SPE, or the two former methods alone. The determination of the 46 pesticide residues in the spiked chrysanthemum samples was performed by GC with electron capture detection. The average recoveries ranged from 71.3 to 102.6% with RSDs of 1.4-15.7% for all of the pesticides. The LOQs were in the range of 0.0015-0.2 mg/kg, while the LODs were between 0.0005 and 0.1 mg/kg. The satisfactory accuracy, and precision, in combination with a good separation and few interferences, have demonstrated the strong potential of this technique for its application in chrysanthemum analysis.

Vortex-assisted matrix solid–liquid dispersive microextraction for the analysis of triazole fungicides in cotton seed and honeysuckle by gas chromatography

“…Liquid-liquid extraction (Guo et al, 2010;Pizzutti et al, 2007), low-temperature precipitation (Li et al, 2007;Su et al, 2011), gel permeation chromatography (Fernandez Moreno, Arrebola Lieanas, Garrido Frenich, & Martinez Vidal, 2006;Xue et al, 2013), and treatment with sulfuric acid (Xue, Hao, & Peng, 2008) are traditional cleanup approaches for the removal of complex co-extractives. To reduce the consumption of organic solvents and achieve simple operation, QuEChERS-based methods have attracted much attention for the analysis of targets in oily and CHM commodities (Chen et al, 2012;Guan et al, 2013;Koesukwiwat, Ehotay, Mastovska, Dorweiler, & Leepipatpiboon, 2010) and showed good efficiency.…”

Rapid and sensitive analysis of nine fungicide residues in chrysanthemum by matrix extraction-vortex-assisted dispersive liquid–liquid microextraction

“…This proposed method was superior in the levels of LODs, LOQs and EFs, implying it could achieve much higher sensitivity and enrichment compared with other reported techniques. As a microextraction approach, ME-VADLLME has fulfilled environmental considerations by only using a total organic solvent amount of 5.05 mL per sample, whereas 20-90 mL of organic solvent is typically required by most of other methods [3,5,7,8,34,[45][46][47]. Without the need to endure lengthy and time-consuming procedures taking more than 30 min for SPE, MSPD, GPC solvent evaporation, or SPME analyte equilibration [3,[6][7][8]34,[44][45][46][47], the combination method based on dispersive analyte transfer is able to perform simultaneous extraction/preconcentration rapidly within 15 min, and allows high sample throughput in routine screening exercise.…”

“…Chrysanthemum is known as a complex matrix comprising of pigments, alkaloids, flavonoids, sterols, and essential oils, etc. To remove the potential co-extractives that may interfere with the determination of the analytes of interest, isolation of pesticides from chrysanthemum needs complicated cleanup procedures, involving gel permeation chromatography (GPC) and solid phase extraction (SPE) [8]. These procedures usually require large amounts of solvents and are time-consuming, and also presented relatively high limits of detection (LODs).…”

Analysis of pesticide residues in tobacco with online size exclusion chromatography with gas chromatography and tandem mass spectrometry

“…Detection of pesticide residues in fruit, vegetable, and tobacco with GC with electron capture detection (ECD), GC–MS/MS and LC–MS/MS has been reported in many studies . However, the samples which were injected into GC or LC usually contain components harmful to the equipment and affect the analysis results.…”