title: Determination of isophorone in food samples by solid-phase microextraction coupled with gas chromatography-mass spectrometry.
abstract: A simple and sensitive method for the determination of isophorone in food samples was developed by headspace solid-phase microextraction (HS-SPME) coupled with gas chromatography-mass spectrometry (GC-MS). Isophorone was separated within 10 min by GC-MS using a DB-1 capillary column and detected with selective ion monitoring mode. The HS-SPME using a polydimethylsiloxane/divinylbenzene (PDMS/DVB) fiber provided effective sample enrichment, and was carried out by fiber exposition at 60 degrees C for 45 min. The extracted isophorone was easily desorbed by fiber exposition in the injection port of a capillary GC-MS system, and carryover was not observed. Using this method, the calibration curve of isophorone was linear in the range 20-1000 pg/mL, with a correlation coefficient 0.9996 (n = 18), and the detection limit (S/N = 3) was 0.5 pg/mL. The HS-SPME/GC-MS method showed 25,000-fold higher sensitivity than the direct injection method (1 microL injection). The within-day and between-day precisions (relative standard deviations) at the concentration of 1 ng/mL isophorone were 3.9% and 6.1% (n=5), respectively. This method was successfully applied to the analysis of food samples without interference peaks. The recoveries of isophorone spiked into food sample were above 84% for a 50 or 500 pg/mL spiking concentration. The analytical results of the contents of isophorone in various food samples were presented.
authors: School of Pharmacy, Shujitsu University, Nishigawara, Okayama 703-8516, Japan. hkataoka@shujitsu.ac.jp
authors: Hiroyuki
authors: H
authors: Kataoka
authors: Yohei
authors: Y
authors: Terada
authors: Reiko
authors: R
authors: Inoue
authors: Kurie
authors: K
authors: Mitani
mesh_terms: D003512:Cyclohexanones / Q000032:analysis*; D005504:Food Analysis / Q000379:methods; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D015394:Molecular Structure; D015203:Reproducibility of Results; D052617:Solid Phase Microextraction / Q000379:methods*
chemical_list: D003512:Cyclohexanones; C005940:isophorone