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To detect various serotypes of Shiga toxin-producing Escherichia coli (STEC) in food, methods independent of serotyping are needed. We established procedures to isolate STEC using a rapid and sensitive loop-mediated isothermal amplification (LAMP) assay targeting the Shiga toxin (ST) gene and a method of plating LAMP assay positive dilutions onto media for the selection of E. coli. After incubation, suspensions of a colony or some colonies were tested in the LAMP assay. Positive suspensions were diluted and plated onto selective media. The procedure was repeated. Finally, LAMP positive colonies were confirmed as STEC and serotype. As a result of surveillance in beef in 2005-2007, 11 of 720 samples (1.5%) tested positive for the ST gene by LAMP assay. Serotype O8, O128, and O-untypeable STEC were isolated from the samples by the newly established procedure. It was demonstrated that the procedure was effective for detecting STEC independent of serotype.

Ester types (2, 4-dichlorophenoxyacetic acid (2, 4-D) ethyl, 2, 4-D butyl and MCPA-thioethyl) and free acid types (2, 4-D, 2, 4, 5-trichlorophenoxyacetic acid (2, 4, 5-T), 2-methyl-4-chlorophenoxyacetic acid (MCPA), m-chloroperbenzoic acid (MCPB), mecoprop and dichlorprop) of phenoxy acid herbicides in agricultural products were simultaneously extracted from samples with acetone for vegetables/fruits, and with acetonitrile for cereals/beans, and then re-extracted with ethyl acetate. Three ester types of herbicides extracted from the samples were cleaned up by Sep-Pak[○!R] Florisil, and then determined by ECD-GC and GC-MS (SIM). Recoveries of the ester types of herbicides determined by GC and GC-MS spiked at 1.25 ppm to asparagus, taro, brown rice and corn were 61.4-76.9% and 50.8-63.9%, respectively. Six free acid types of herbicides were esterified by pentafluorobenzyl bromide or diazomethane and determined by GC-MS (SIM) without cleaning up by solid phase extraction. Recoveries of the free acid types of herbicides esterified by pentafluorobenzylation and methylation spiked at 1.25 ppm to the samples were 68.5-98.5% and 53.7-88.1%, respectively. It was clarified that the concentration of pentafluorobenzyl bromide in acetone should be 5-10% to have sufficient recoveries for the esterification. Methylation was superior to pentafluorobenzylation for the simplicity of manipulation, but was inferior for the sensitivity of GC and GC-MS.

Organochlorine pesticides as well as synthetic antibacterialagents in cattle meats were extracted with acetonitrile, and the extract was divided into two parts for the individual clean-up. One part of the extract was cleaned up by silica gel column chromatography, and determined by electron capture detecter-gas chromatography (ECD-GC) for organochlorine pesticides. Another part of the extract was cleaned up by washing with n-hexane in the case of edible meats, or by solid phase extraction with Sep-pak Alumina N or tC18 mini column in the case of edible viscera, and determined by HPLC with a UV detector for the synthetic antibacterialagents. Recoveries of 7 organochlorine pesticides in edible meats spiked at 0.1 ppm were 54.3-104.6%, and recoveries of 13 antibacterialagents in edible viscera spiked at 0.4 ppm were 59.1-105.3%. Confirmation of nicarbazin (NCZ) in chicken, trimethoprim (TMP) spiked in pork by GC-MS were studied.

The simultaneous determination of residual 13 synthetic antibacterials in edible viscera by HPLC was studied and the clean up method was developed by Sep-Pak Alumina N and also tC18 cartridges. This method was applicable to sulfamerazine, sulfadimidine, sulfamonomethoxine, sulfadimethoxine, sulfaquinoxaline, ormethoprim, trimethoprim, pyrimethamine difulazon, clopidol, morantel, carbadox and nicarbazin in the bovine liver and swine kidney. The recoveries of the addition of 0.4μg/g of these antibacterials to the bovine liver and to the swine kidney were in the range of 54.0 to 74.9%, and their detection limits were in the range of 30 to 50 ppb.

The stability of the standard solutions for 20 organophosphorus, 19 organonitrogen and 7 pyrethroid pesticides during storage under different conditions (solvent, concentration of pesticides, with or without light) was investigated by gas chromatograph (GC). All of the investigated 46 pesticides were stable during twenty days under all conditions except storage under sunlight. It was found that 12 pesticides dissolved in acetone in low concentration decreased under sunlight. Photo-changed compounds of aldicarb, disulfoton, and fensulfothion in acetone were investigated by GC. It was clarified that these pesticides were gradually changed into their oxydative products (sulfoxide and sulfone). Consequently, it is recommendable that the standard solution for pesticides should be dissolved in hexane, in high concentration and kept in the dark.

Twenty-eight of the 302 Salmonella strains isolated from patients with overseas travelers' diarrhea who were examined at Kansai Airport Department Station during the 6-year period between 2001 and 2007 showed decreased susceptibility to both nalidixic acid (NA) and ciprofloxacin (CPFX) (MIC of NA, 16-64 microg/mL; MIC of CPFX, 0.064-2.0 microg/mL). These 28 strains revealed no variations in the quinolone resistance-determining region; however, 25 of the strains showed retention of the qnr gene. The qnr-retaining Salmonella belonged to 6 serotypes, and 21 and 4 of the 25 strains showed qnrS1 and qnrS2, respectively. The most common serovar was S. Corvallis (17 strains).

Various pesticides in polished and unpolished rice were simultaneously extracted and determined by ion-trap GC/MS with chemical ionization using isobutane. Among 62 pesticides (25 organonitrogen pesticides, 25 organophosphorus pesticides, 7 organochlorine pesticides and 5 pyrethroid pesticides), almost all, except BHC, endrin and endosulfan, gave several fragment ions in GC/MS (CI method) and the sensitivities were ten times higher than in the EI mode.Recoveries of the pesticides spiked at 0.1ppm in rice were more than 50% except for several pesticides, and the detection limit for each was 0.005ppm by the proposed method.

A simple and rapid systematic gas chromatographic determination of 43 organophosphorus, 24 organonitrogen, 14 organochlorine, and 11 pyrethroid pesticides in brown rice was developed. The pesticides were extracted from samples with acetonitrile, and this extract was evaporated to dryness. The residue was dissolved in acetone, and organophoshorus pesticides were directly determined by FPD-GC. Another part of the solvent was applied to a Sep-pak Florisil cartridge, and organonitrogen pesticides were eluted with 50% ethyl acetate in n-hexane and determined by NPD-GC. On the other hand, organochlorine and pyrethroid pesticides were eluted with 5% ethyl acetate in n-hexane and determined by ECD-GC. This simple method affords a high recovery of hydrophilic pesticides, allows rapid analysis, and is cheap to perform. Residual pesticides in brown rice (246 samples) imported from the U. S. A., China and Australia were investigated by the proposed method, and 0.01-0.1ppm of malathion was found in 3 samples from the U. S. A., and 6 samples from China. The detection limit of the proposed method was 0.001ppm for organophosphorus and organochlorine pesticides and 0.01ppm for organonitrogen and pyrethroid pesticides.

A rapid and sensitive method for the determination of fenoxaprop-ethyl in polished rice and brown rice by HPLC was developed. The pesticide was extracted from samples with acetonitrile. For polished rice, the extract was evaporated to dryness. For brown rice, the fats in the extract were removed with hexane saturated with acetonitrile, and the acetonitrile layer was evaporated to dryness. The residues were dissolved in hexane, and the hexane solution was cleaned-up with a Sep-pak® Florisil column. Recoveries of fenoxaprop-ethyl were 87.2-104.6% for polished rice and 88.3-108.3% for brown rice.No pesticide was found in 6 polished rice and 41 brown rice samples from the U. S. A.. The detection limits of fenoxaprop-ethyl in polished rice and brown rice were both 0.01ppm.

A separative determination method of benfuracarb, carbosulfan, carbofuran and 3-hydroxycarbofuran in agricultural products by GC and HPLC was developed. When benfuracarb and carbosulfan in raw extract or slightly cleaned-up extracts of foods were measured by GC, almost all of them was not recovered, though a corresponding amount of carbofuran was detected. On the other hand, when the same GC test solutions were measured by HPLC, benfuracarb and carbosulfan were quantitatively recovered regardless of the degree of cleanup (with or without Sep-pak Silica or Florisil) of the test solution.Accordingly, benfuracarb and carbosulfan in test solution coexisting with food components were decomposed to carbofuran during GC analysis, and the degree of the decomposition depended on the kind of foods. In order to prevent the decomposition, it was necessary to clean-up the test solutions for benfuracarb and carbosulfan sufficiently.

An antibacterial substance was detected in frozen shrimp imported from Thailand by use of a simplified bioassay. It appeared to be a tetracycline by classified bioassay, but we could not distinguish between tetracycline (TC) and oxytetracycline (OTC) by micro-bioautography. We were able to identify the antibiotic as OTC by HPLC with a UV detector, fluorescence detector and photodiodearray detector. The content of OTC in the frozen shrimp was 1.90ppm. The detection limit of OTC was 0.01ppm by the fluorescence detector, and 0.2ppm through biological and physico-chemical determination.

A simple and rapid simultaneous gas chromatographic determination of 24 organophosphorus, 30 carbamate, 14 organochlorine and 8 pyrethroid pesticides in extract of polished rice was developed. The pesticides were extracted from the sample with methanol and acetone, and this extract was evaporated to dryness. The residue was dissolved in acetone. This simple method affords a high recovery of hydrophilic pesticides, allows rapid analysis, and is cheap to perform. No pesticide was found among 112 samples of polished rice from Thailand, the U. S. A, China and Australia. The detection limits of the proposed method were 0.001ppm for organophosphorus and organochlorine pesticides and 0.01ppm for carbamate and pyrethroid pesticides.

A method for systematic determination of organophosphorus, carbamate, organochlorine and pyrethroid pesticides in polished rice by GC was developed. The pesticides were extracted from the sample with acetone-water (7:3) mixture, and re-extracted into ethyl acetate. Organophosphorus pesticides in the extract were directly determined without purification. On the other hand, half of the extract was purified over a Florisil column and used for determination of organochlorine and pyrethroid pesticides. The other half of the extract was purified on a silica gel column and used for determination of carbamate pesticides. No pesticide was found in 56 samples of polished rice from Thailand. The detection limit of the proposed method was 0.001ppm for organophosphorus and organochlorine pesticides and 0.01ppm for carbamate and pyrethroid pesticides.

A procedure for determination of 20 organophosphorus, 19 carbamate and 5 pyrethroid pesticides in raw coffee beans by gas chromatography was developed. Extract of coffee beans was directly analyzed for organophosphorus and pyrethroid pesticides, and purified by silica gel column chromatography before GC analysis for carbamate pesticides. No residual pesticide was detected, but much bromine was detected in 11 samples imported from 10 countries. The detection limit was 0.001ppm for organophosphorus pesticides, 0.01ppm for carbamate and pyrethroid pesticides by the proposed method, and 0.05ppm for bromide.

A method of preparing a test solution for 29 organophosphorus and 12 pyrethroid pesticides from vegetables and fruits was systematically developed. It consists of extraction with acetone followed by clean-up with coagulating solution and, for cereals and beans, by extraction with acetonitrile followed by washing with hexane.Twenty-nine organophosphorus and 10 pyrethroid pesticides were simultaneously determined by FPD-GC and NPD-GC, respectively. Aliethrin and permethrine were individually determined by GC/MS (SIM). Recovery tests for the pesticides spiked at 0.01ppm for organophosphorus pesticides and 0.25ppm for pyrethrine pesticides were satisfactory, and no interfering peaks were observed in the determination except in the case of onion in FPD-GC.Recoveries of the above-mentioned pesticides in tea leaves were compared between acetone extraction according to the proposed method and the official hot water steeping method. Almost all of the pesticides were recovered by the proposed method, but only a small part of the pesticides were recovered by the official method.Contents of residual pesticides in imported agricultural products (pumpkin, onion, orange, lemon, wheat, soybean, tea) were determined by the proposed method. Chlorpyrifos in lemon (175ppb) and orange (83ppb) from the U. S. A and fenvalerate in tea (157ppb) from China were detected.

Development of a procedure for simultaneous analysis of triadimefon, triadimenol, triapentenol, pacrobutrazole, diniconazole, propiconazole, benalaxyl and bitertanol in vegetables and fruits is described. The pesticides were extracted from the sample and analyzed by FTD-GC. Recoveries of the pesticides spiked at 0.2ppm were 67.8-112.5% from 9 kinds of samples except pumpkin. The peaks detected in each sample were confirmed by GC/MS after clean-up by Florisil column chromatography. Triadimefon was eluted with 15% ethyl acetate/hexane and the others were eluted with 30% ethyl acetate/hexane from the Florisil column. Triadimefon (0.41-1.29ppm) and triadimenol (0.22-1.03ppm) were found in all of 6 pineapple skin parts and bitertanol (0.27-0.95ppm) was found in 5 banana skin parts (total 7 samples), but they were not detected in the edible parts of pineapple or banana. Detection limits of the 8 fungicides by the proposed method were 0.01ppm in the samples.