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A rapid, specific, and sensitive method based on quick polar pesticide extraction and ultra-high-performance liquid chromatography coupled to high-resolution mass spectrometry with an Orbitrap analyzer was evaluated. Usually, pesticides were analyzed individually using derivatization or ion-pairing techniques and detection by ion chromatography. We identified and simultaneously quantified 6 highly polar compounds (glyphosate, aminomethyl phosphonic acid (AMPA), phosphonic acid, fosetyl-Al, chlorate, and perchlorate) in 83 processed fruits and vegetables as well as 15 infant foods. Isotopically labeled internal standards 18O4-perchlorate, 18O3-chlorate, and 13C2 15N-glyphosate were applied to quantify five polar compounds and to compensate for any factor affecting the recovery rates. Only AMPA was quantified using a standard addition approach to compensate for matrix effects. This analytical methodology is fast and reliable, and it is also able to satisfy the strict requirements of infant food analysis.

A problem concerning significant amounts of nicotine in dried wild mushrooms (mainly Boletus edulis from China) has been reported to the European Commission. As a consequence, the European Food Safety Authority (EFSA) proposed temporary maximum residue levels (MRLs) of 0.036 mg kg(-1) for fresh wild mushrooms and 1.17 mg kg(-1) for dried wild mushrooms (2.3 mg kg(-1) for dried ceps only). The EFSA also highlighted the necessity for a monitoring and testing programme to be launched by food business operators at the start of the 2009 harvest season. In the present study, a quick and sensitive analytical method for routine analysis of nicotine in fresh and dried mushrooms was developed and validated by a single-laboratory procedure. The method, which employs an LC-MS/MS system and (+/-)-nicotine-d(4) as internal standard, has a limit of quantification of 6 and 60 microg kg(-1) for fresh and dried product, respectively. Analyses of samples spiked with different levels of nicotine showed recoveries ranging from 107 to 122%, with relative standard deviations of 2.9-10.1% depending on the spiking level. The combined uncertainties, calculated at a low level for frozen (0.015 mg kg(-1)) and a high level for the dried (2 mg kg(-1)) matrix, were 13 and 10%, respectively. Application of the method to real samples of mushrooms purchased on the market or obtained from local producers showed nicotine levels ranging 0.01-0.04 and 0.1-4.5 mg kg(-1) in fresh/frozen and dried matrices, respectively. To establish reasons for the unexpectedly high levels of the nicotine in dried matrices, preliminary laboratory experiments involving drying mushrooms were performed under various conditions.

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A liquid chromatographic method with electrospray ionization tandem mass spectrometry (LC/ESI-MS/MS) has been developed for the sensitive and selective determination of seven benzoylphenylurea insecticide residues (diflubenzuron, triflumuron, lufenuron, flufenoxuron, teflubenzuron, chlorfuazuron, hexaflumuron) in pear baby purée, concentrated lemon juice, and tomato pulp. The general sample extraction/partition method for our established multiresidue methods has been used. The entire procedure involves extraction of residues with acetone and partition into ethyl acetate/cyclohexane. Chromatographic determination was performed using a C18 column and isocratic elution. Fourteen MS/MS transitions of precursor ions were monitored (two for each pesticide) using negative ESI. The majority of mean recoveries at fortification levels of 0.002-0.020 and 0.020-0.200 mg/kg were in the range 77-102% with relative standard deviations between 2 and 10%. The excellent sensitivity and selectivity of this LC/MS/MS method allowed quantitation and identification at low levels in difficult matrices with a run time of 4 min.