Simultaneous determination of 18 preservative residues in vegetables by ultra high performance liquid chromatography coupled with triple quadrupole/linear ion trap mass spectrometry using a dispersive-SPE procedure

Optimization of double-vortex-assisted matrix solid-phase dispersion for the rapid determination of paraben preservative residues in leafy vegetables

“…1 Liao et al found MeP in vegetable samples from Albany with concentrations ranging from 0.041 to 69.9 ng g À1 (d.w.), 3 whereas MeP was detected in vegetables with concentrations ranging from n.d. to 81.0 ng g À1 (d.w.) in Beijing, China. 1 Moreover, our results for MeP have higher concentration than those in vegetable samples collected from Chongqing, China, as reported by Zhou et al, 8 and the samples collected from Seville, Spain, as reported by Aparicio et al 10 The MeP concentrations from the vegetables in Chongqing ranged from 0.9 to 5.0 ng g À1 (d.w.); 8 and those in the samples from Seville ranged from 0.2 to 4.4 ng g À1 (d.w.). 10 However, the results we detected for MeP are lower than the results from the vegetable samples collected in nine cities in China, as reported by Liao et al, which ranged from 0.042 to 2170 ng g À1 (d.w.) with an average of 81.1 ng g À1 (d.w.).…”

“…[13][14][15][16][17] Either methanol or acetonitrile was commonly used as the extracting solvent, and either vortex or ultrasonic was oen employed as an extraction mechanic force to increase the extraction efficiency. 8,10,13,14,16,22 To select the signicant type of variables as listed above (also shown in Table 2), a FMLCD with 2 or 3 non-numeric variables was rst applied for selecting the most signicant factors. The experimental domain with twelve experiments in random order plus the corresponding experimental results (represented as total peak area) are illustrated in Table 2.…”

“…Therefore, these emerging contaminants have the potential to accumulate in roots and leaves, which can further jeopardize human health upon ingestion. Various extraction methods, such as solidliquid extraction, 2,3 QuEChERS (quick, easy, cheap, effective, rugged, and safe) 1,8 and ultrasound-assisted extraction 9,10 have been reported for the extraction of parabens in different vegetable samples. Aer extraction, various clean-up procedures, such as NH 2 -solid-phase extraction (SPE), 2,3 multi-walled carbon nanotubes SPE, 1 dispersive solid-phase extraction (d-SPE), 10 and dispersive liquid-liquid microextraction (DLLME), 9 have been applied.…”

Screening of pesticide residues in Traditional Chinese Medicines using modified QuEChERS sample preparation procedure and LC-MS/MS analysis

“…Ultra High Performance Liquid Chromatography coupled to Tandem Mass Spectrometry (UHPLC-MS/MS) can provide qualitative and quantitative information for a wide range of analytes [35]. Its dynamic multiple reaction monitoring (dMRM) mode not only has the advantages of MRM mode, such as reduced interference and improved instrument analysis accuracy [36], but can also scan in positive and negative ion modes simultaneously. This saves analysis time and improves efficiency considerably.…”