Nicotine determination in mushrooms by LC-MS/MS with preliminary studies on the impact of drying on nicotine formation.
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.
Cavalieri
Chiara
C
Stazione Sperimentale per l'Industria delle Conserve Alimentari (SSICA), Parma, Italy. chiara.cavalieri@gmail.com
Bolzoni
Luciana
L
Bandini
Mirella
M
D000363:Agaricales / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D005506:Food Contamination / Q000032:analysis*; D057141:Food, Preserved / Q000032:analysis*; D005628:Frozen Foods / Q000032:analysis; D008452:Maximum Allowable Concentration; D009538:Nicotine / Q000032:analysis*; D015203:Reproducibility of Results; D053719:Tandem Mass Spectrometry / Q000379:methods*
D009538:Nicotine