PMID- 22981507
OWN - NLM
STAT- MEDLINE
DCOM- 20130107
LR  - 20120926
IS  - 1873-3778 (Electronic)
IS  - 0021-9673 (Linking)
VI  - 1260
DP  - 2012 Oct 19
TI  - Planar solid phase extraction clean-up for pesticide residue analysis in tea by 
      liquid chromatography-mass spectrometry.
PG  - 42-53
LID - S0021-9673(12)01339-8 [pii]
LID - 10.1016/j.chroma.2012.08.088 [doi]
AB  - Efficient clean-up is indispensable for preventing matrix effects in 
      multi-residue analysis of pesticides in food by liquid and gas chromatography (LC 
      and GC) coupled to mass spectrometry (MS). High-throughput planar solid phase 
      extraction (HTpSPE) was recently introduced as a new clean-up concept in residue 
      analysis of pesticides in fruit and vegetables (C. Oellig, W. Schwack, 2011 
      [45]). Thin-layer chromatography (TLC) was used to completely separate pesticides 
      from matrix compounds and to focus them into a sharp zone, followed by extraction 
      of the target zone by the TLC-MS interface. As rather challenging matrices, tea 
      samples were chosen in this study. Besides chlorophylls and polyphenols, high 
      amount of caffeine is co-extracted resulting in strong matrix effects both in 
      LC-MS and GC-MS. The former HTpSPE procedure was adapted to initial extracts of 
      green and black tea resulting in colorless extracts nearly free of matrix effects 
      and interferences, as shown for seven chemically representative pesticides 
      (acetamiprid, penconazole, azoxystrobin, chlorpyrifos, pirimicarb, fenarimol, and 
      mepanipyrim). LC-MS/MS calibration curves obtained in the range of 0.002-0.5 
      mg/kg from matrix-matched standards and solvent standards were nearly identical 
      and demonstrated the effectiveness of clean-up by HTpSPE. Mean recoveries 
      determined by LC-MS/MS against solvent standards at spiking levels of 0.01 and 
      0.1 mg/kg ranged between 72 and 114% with relative standard deviations (RSDs) of 
      0.7-4.7% (n=4), while LC-MS measurements of tea samples spiked at 1 mg/kg 
      provided recoveries of 81-104% with RSDs of 1.2-4.9% (n=6). Using LC-MS/MS, the 
      method showed high sensitivity with signal-to-noise ratios>10 for concentrations 
      below 0.002 mg/kg. HTpSPE of one sample was done in a few minutes, while numerous 
      samples were cleaned in parallel at minimal costs with very low sample and 
      solvent consumption.
CI  - Copyright (c) 2012 Elsevier B.V. All rights reserved.
FAU - Oellig, Claudia
AU  - Oellig C
AD  - Institute of Food Chemistry, University of Hohenheim, Garbenstrasse 28, 70599 
      Stuttgart, Germany. claudia.oellig@uni-hohenheim.de
FAU - Schwack, Wolfgang
AU  - Schwack W
LA  - eng
PT  - Journal Article
DEP - 20120901
PL  - Netherlands
TA  - J Chromatogr A
JT  - Journal of chromatography. A
JID - 9318488
RN  - 0 (Pesticide Residues)
RN  - 0 (Tea)
SB  - IM
MH  - Chromatography, Thin Layer/*methods
MH  - Linear Models
MH  - Mass Spectrometry/*methods
MH  - Pesticide Residues/analysis/*isolation & purification
MH  - Reproducibility of Results
MH  - Signal-To-Noise Ratio
MH  - Solid Phase Extraction/*methods
MH  - Tea/*chemistry
EDAT- 2012/09/18 06:00
MHDA- 2013/01/08 06:00
CRDT- 2012/09/18 06:00
PHST- 2012/06/28 00:00 [received]
PHST- 2012/08/27 00:00 [revised]
PHST- 2012/08/29 00:00 [accepted]
PHST- 2012/09/18 06:00 [entrez]
PHST- 2012/09/18 06:00 [pubmed]
PHST- 2013/01/08 06:00 [medline]
AID - S0021-9673(12)01339-8 [pii]
AID - 10.1016/j.chroma.2012.08.088 [doi]
PST - ppublish
SO  - J Chromatogr A. 2012 Oct 19;1260:42-53. doi: 10.1016/j.chroma.2012.08.088. Epub 
      2012 Sep 1.