[Comparison of three different QuEChERS sample treatment methods in the analysis of more than one hundred pesticide residues in tobacco by gas chromatography-tandem mass spectrometry].

With a combination of QuEChERS method and gas chromatography-tandem mass spectrometry (GC-MS/MS) technique, three sample treatment methods (solvent exchange method, toluene dilution method, hexane liquid-liquid extraction method) were established to analyse more than one hundred pesticide residues in tobacco. The 155 pesticide analytes contained 58 organophosphorus, 28 organochlorine, 10 pyrethroids, 10 acyl amide, 11 carbamate, 7 dinitroaniline and 31 other family pesticides. Comparison of the three treatment methods was investigated on performances including matrix effect, co-extracted matrix, peak interference, recovery and the limit of quantification (LOQ).

Determination of chlorinated phenoxy acid herbicides in tobacco by modified quechERS extraction and high-performance liquid chromatography/tandem mass spectrometry.

A new method for determination of phenoxy acid herbicide residues in tobacco based on the use of liquid extraction/partition and dispersive SPE followed by HPLC/electrospray ionization-MS/MS is reported. Formic acid (2%, v/v) in acetonitrile as the extraction solvent and inclusion of citrate buffer helped partitioning of all analytes into the acetonitrile phase. Quantitative analysis was done in the multiple-reaction monitoring mode using two combinations of selected precursor ion and product ion transition for each compound.

Analysis of 118 pesticides in tobacco after extraction with the modified QuEChRS method by LC-MS-MS.

A liquid chromatography-tandem quadrupole mass spectrometry (LC-MS-MS) multi-residue method for the simultaneous target analysis of a wide range of pesticides in tobacco has been developed. Gradient elution has been used in conjunction with positive mode electrospray ionization tandem mass spectrometry to detect up to 118 pesticides in tobacco. The recoveries obtained for each pesticide ranged between 70 and 118% at two spiked concentration levels.

Development and validation of a method for the determination of 159 pesticide residues in tobacco by gas chromatography-tandem mass spectrometry.

A multiresidue gas chromatography-tandem mass spectrometry (GC-MS/MS) method was developed for the analysis of 159 multiclass pesticides in tobacco. A modified QuEChERS sample preparation technique, based on acetonitrile extraction and toluene dilution, followed by dispersive solid-phase extraction (d-SPE) cleanup using primary-secondary amine (PSA) and octadecyl (C18) sorbents, was used for sample treatment. Key performance parameters investigated were linearity, recovery, relative standard deviation (RSD), limit of detection, and limit of quantitation.

[Determination of 132 pesticide residues in tobacco by gas chromatography-tandem mass spectrometry].

A simple method for the determination of 132 pesticide residues in tobacco by gas chromatography-triple quadrupole tandem mass spectrometry (GC-MS/MS) was established. The influences of different extraction solvents, different buffer systems and different purifying agents on the recoveries of pesticides were investigated. The tobacco sample was extracted with acetonitrile, then cleaned up by the mixed sorbents of primary secondary amine (PSA) and octadecylsilane (C18E).