TY - JOUR T1 - Determination of aflatoxins in food samples by automated on-line in-tube solid-phase microextraction coupled with liquid chromatography-mass spectrometry. AU - Nonaka,Y, AU - Saito,K, AU - Hanioka,N, AU - Narimatsu,S, AU - Kataoka,H, Y1 - 2009/03/18/ PY - 2009/01/10/received PY - 2009/03/04/revised PY - 2009/03/13/accepted PY - 2009/3/31/entrez PY - 2009/3/31/pubmed PY - 2009/7/3/medline SP - 4416 EP - 22 JF - Journal of chromatography. A JO - J Chromatogr A VL - 1216 IS - 20 N2 - A simple and sensitive automated method for determination of aflatoxins (B1, B2, G1, and G2) in nuts, cereals, dried fruits, and spices was developed consisting of in-tube solid-phase microextraction (SPME) coupled with liquid chromatography-mass spectrometry (LC-MS). Aflatoxins were separated within 8 min by high-performance liquid chromatography using a Zorbax Eclipse XDB-C8 column with methanol/acetonitrile (60/40, v/v): 5mM ammonium formate (45:55) as the mobile phase. Electrospray ionization conditions in the positive ion mode were optimized for MS detection of aflatoxins. The pseudo-molecular ions [M+H](+) were used to detect aflatoxins in selected ion monitoring (SIM) mode. The optimum in-tube SPME conditions were 25draw/eject cycles of 40 microL of sample using a Supel-Q PLOT capillary column as an extraction device. The extracted aflatoxins were readily desorbed from the capillary by passage of the mobile phase, and no carryover was observed. Using the in-tube SPME LC-MS with SIM method, good linearity of the calibration curve (r>0.9994) was obtained in the concentration range of 0.05-2.0 ng/mL using aflatoxin M1 as an internal standard, and the detection limits (S/N=3) of aflatoxins were 2.1-2.8 pg/mL. The in-tube SPME method showed >23-fold higher sensitivity than the direct injection method (10 microL injection volume). The within-day and between-day precision (relative standard deviations) at the concentration of 1 ng/mL aflatoxin mixture were below 3.3% and 7.7% (n=5), respectively. This method was applied successfully to analysis of food samples without interference peaks. The recoveries of aflatoxins spiked into nuts and cereals were >80%, and the relative standard deviations were <11.2%. Aflatoxins were detected at <10 ng/g in several commercial food samples. SN - 1873-3778 UR - https://www.unboundmedicine.com/medline/citation/19328492/Determination_of_aflatoxins_in_food_samples_by_automated_on_line_in_tube_solid_phase_microextraction_coupled_with_liquid_chromatography_mass_spectrometry_ L2 - https://linkinghub.elsevier.com/retrieve/pii/S0021-9673(09)00429-4 DB - PRIME DP - Unbound Medicine ER -