Determination of acrylamide in foodstuffs by liquid chromatography ion-trap tandem mass-spectrometry using an improved clean-up procedure

摘要

The present paper describes an analytical method based on liquid chromatography coupled to tandem mass-spectrometry (LC-MS/MS) for the determination of acrylamide in foodstuffs. Atmospheric pressure chemical ionization (APCI) as ionization source and an ion-trap (LCQ) analyzer were used, and to the best of our knowledge, this hyphenated technique has not ever been employed to this purpose. In order to obtain clean extracts an improved purification procedure based on the coupling of two highly cross-linked polystyrene-divinylbenzene polymeric sorbents: Strata-X-C and ENV+, was also developed. High recoveries (85%) and good reproducibility (relative standard deviation of 12%) were obtained using the two solid-phase extraction cartridges in combination. One hundred percent water as mobile phase was used for the LC separation. The obtained figures of merit showed detection limits of 250 pg for standards and 45 ng/g for samples, and run-to-run and day-to-day precisions of 3.3 and 8%, respectively. Acrylamide (AA) was determined in several of the most frequently eaten carbohydrate-rich foodstuffs commercialized in Spain such as potato crisps and chips, biscuits, crisp breads, pastry, dried fruits, chocolates and coffee. For the first time, a typical pastry product called as "churros" and highly consumed in Spain was also studied. Some of the products tested such as french fries frozen or "churros" were household cooked. Acrylamide was determined in the selected food commodities using the developed analytical methodology. A commonly used method by liquid chromatography coupled to tandem mass-spectrometry with a triple quadrupole as mass analyzer (LC-QqQ-MS/MS) was also applied in order to validate the analytical results. Different levels of acrylamide were obtained and pastry and dried fruits showed the lower levels (< 20 ng/g). Potato chips and french fries gave values of the order of 500-9250 ng/g. (c) 2005 Elsevier B.V. All rights reserved.