Assessment of 3-MCPD levels in coffee and coffee substitutes by simplified QuEChERS method

摘要

A new simplified QuEChERS method, with the use of PSA sorbent and without the addition of magnesium sulphate, was established for the determination of 3-monochloropropane-1,2-diol (3-MCPD) in coffee and coffee substitutes. The final extracts were derivatised with phenylboronic acid and analysed by gas chromatography-mass spectrometry. The recoveries were in the ranges of 90.5-107 % for all coffee types. The calculated limit of detection was 2.5 mu g kg(-1) and the linearity within the range of 2-200 ng mL(-1). In real samples the highest level of 3-MCPD was detected in soluble coffee surrogates (average 135.6 mu g kg(-1)), especially in those prepared from roasted spelt or barley, where they reached even up to 398.1 mu g kg(-1). The contents of 3-MCPD in natural instant and ground coffee samples were much lower with the average of 16.6 and 14.1 mu g kg(-1), respectively. Any impact of factors such as manufacturer or coffee origin was not observed.