* Corresponding author 2-Alkylcyclobutanones (2-ACBs) are recognized as a marker of irradiation in lipid-containing food products. Here, a rapid method for the analysis of 2-dodecylcyclobutanone (2-DCB) and 2-tetradecylcyclobutanone (2-TCB) in irradiated food products using direct solvent extraction (DSE) was developed, and the extraction efficiency was compared to that of the Soxhlet extraction method (EN 1785), which is the official method for this analysis. Briefly, 2-ACBs were extracted either by using a Soxhlet apparatus or by DSE with n-hexane. The lipid extract was purified by GPC followed by a silica gel cartridge column. Finally, 2-DCB and 2-TCB were measured using GC-MS/MS. The extraction efficiency of 2-ACBs by the DSE method was similar to that of the Soxhlet extraction method. The trueness of 2-DCB and 2-TCB spiked at 50 ng/g in lipid extracts of beef, pork, chicken, cheese and salmon with the proposed method were 76.6 to 91.6 and 81.3 to 109.0 , respectively. The limits of detection for 2-DCB and 2-TCB in lipid extracts were 15 and 20 ng/g, respectively.

A simple determination method of hydramethylnon in agricultural products by liquid chromatography-tandem mass spectrometry (LC-MS/MS) was developed. The sample was homogenized with phosphoric acid and extracted with acetone. An aliquot of crude extract was reextracted with hexane and sat. NaCl solution. In the case of tea leaf, solidification processing using ammonium chloride and phosphoric acid was performed before re-extraction with hexane. Clean-up was performed using a silica-gel mini column (500 mg). The LC separation was performed on a C18 column using methanolῌwater (8 : 2) containing 10 mM ammonium acetate as the mobile phase and MS detection with positive ion electrospray ionization. The calibration curve was linear between 0.002ῌ0.2 ῌg/mL of hydramethylnon. Recoveries (nῒ5) of hydromethylnon from 10 kinds of agricultural products fortified at 0.01 ῌg/g (0.05 ῌg/g for pineapple) were 82ῌ110ΐ, and their relative standard deviations were 2ῌ12ΐ.

In the inspection of genetically modified rice, rice taxon-specific DNA could not be detected in processed rice food (bifun: rice vermicelli). The e#ects of using PCR the ratio of rice powder content and temperature of processing on the detection of taxon-specific DNA were examined by means of processing model experiments using cornstarch with 0, 2, 5, 10̮ rice powder by weight. Cornstarch and rice powder were blended with water and subjected to heating, steam-treatment, and autoclaving. The rice taxon-specific DNA was detectable in 2̮ rice powder following heat and steam treatments. After autoclaving, rice taxon-specific DNA was detected only in the 10̮ rice powder product. In the processing model experiment using rice powder, it was found that autoclaving caused severe DNA degradation.

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