Determination of 1,3-dichloropropanol in soy sauce and related products by headspace gas chromatography with mass spectrometric detection: interlaboratory study.
An interlaboratory study was performed to evaluate the effectiveness of a headspace gas chromatography (GC) method for the determination of 1,3-dichloro-propan-2-ol (1,3-DCP) in soy sauce and related products at levels above 5 ng/g. The test portion is mixed with an internal standard (d5-1,3-DCP) and ammonium sulfate in a sealed headspace vial. After achieving equilibrium, the headspace is sampled either by gas-tight syringe or solid-phase microextraction (SPME) and analyzed by GC with mass spectrometric detection. 1,3-DCP is detected in the selected-ion mode (monitoring m/z 79 and 81 for 1,3-DCP and m/z 82 for the deuterated internal standard) and quantified by measurement against standards. Test materials comprising soy, dark soy, mushroom soy, and teriyaki sauces, both spiked and naturally contaminated, were sent to 9 laboratories in Europe, Japan, and the United States; of these, 5 used SPME and 4 used syringe headspace analysis. Test portions were spiked at 5.0, 10.0, 20.0, 100.0, and 500.0 ng/g. The average recovery for spiked blank samples was 108% (ranging from 96-130%). Based on results for spiked samples (blind pairs at 5, 10, 20, 100, and 500 ng/g) as well as a naturally contaminated sample (split-level pair at 27 and 29 ng/g), the relative standard deviation for repeatability (RSDr) ranged from 2.9-23.2%. The relative standard deviation for reproducibility (RSDR) ranged from 20.9-35.3%, and HorRat values of between 1.0 and 1.6 were obtained.
Hasnip
Sarah
S
Central Science Laboratory, Sand Hutton, York, YO41 1LZ, United Kingdom. s.hasnip@csl.gov.uk
Crews
Colin
C
Potter
Nicholas
N
Brereton
Paul
P
Diserens
Henri
H
Oberson
Jean-Marie
JM
D002138:Calibration / Q000592:standards; D005504:Food Analysis / Q000379:methods*; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D015203:Reproducibility of Results; D045730:Soy Foods / Q000032:analysis*; D000517:alpha-Chlorohydrin / Q000031:analogs & derivatives* / Q000032:analysis
C033489:1,3-dichloro-2-propanol; D000517:alpha-Chlorohydrin