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Volume 53 (2012)
- Issue 6 Pages 255-
- Issue 5 Pages 195-
- Issue 4 Pages 157-
- Issue 3 Pages 129-
- Issue 2 Pages 75-
- Issue 1 Pages 1-
Volume 53, Issue 6
Displaying 1-4 of 4 articles from this issue
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Original Paper
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Shizuka SAITO, Satoru NEMOTO, Rieko MATSUDAArticle type: Original Paper
2012 Volume 53 Issue 6 Pages 255-263
Published: December 25, 2012
Released on J-STAGE: March 08, 2013
JOURNAL FREE ACCESSThe applicability of liquid chromatography time-of-flight mass spectrometry (LC-TOF-MS) for determining pesticide residues in agricultural products was investigated. TOF-MS conditions for monitoring target ions, together with their fragment ions, were carefully optimized. The developed LC-TOF-MS method was evaluated for 154 pesticides in soybean and spinach by using matrix-matched standards. No significant matrix effect was observed for most of the tested pesticides at a concentration level of 0.01 mg/kg, where the limits of quantification were less than 0.01 mg/kg for 145 of the 154 pesticides (S/N>10). In addition, no significant interference was observed in the chromatograms of the blank extracts. These results indicate that LC-TOF-MS determination may become a powerful tool for multi-residue analysis of pesticides in agricultural products.View full abstractDownload PDF (1010K)
Note
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Shihomi ITO, Chie KAJIHARA, Motoki OGISO, Nobuyuki KIBUNE, Masatoshi W ...Article type: Note
2012 Volume 53 Issue 6 Pages 264-272
Published: December 25, 2012
Released on J-STAGE: March 08, 2013
JOURNAL FREE ACCESSA analytical method for simultaneous determination of 10 heterocyclic amines (HCAs) applicable to prepared foods on the market was studied. HCAs were extracted with acidic methanol, and then purified on a diatomaceous column and an ion-exchange column prior to LC-MS/MS. The method was validated within laboratory using three groups among the total diet samples (oils and fats, fish and shellfish, meat and eggs). The method showed good precision and trueness (as recovery) in duplicate analyses over 5 days, though there were some unsatisfactory results. Limits of detection (LOD) and quantification (LOQ) of the method were estimated from the deviation of the analytical results in samples spiked at a level of near 1 ng/g. In addition,13 groups of total diet samples, 27 items of retail food ready to eat and a few foods cooked in the laboratory were analyzed using this validated method. The results showed that the method is applicable to the foods tested in this study and provided information on the content of HCAs in some foods in Japan.View full abstractDownload PDF (1222K)
Report
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Motokazu NAKAYAMA, Takashi MIYASHITA, Kouichi HOSOYA, Jun HITOMI, Miki ...Article type: Report
2012 Volume 53 Issue 6 Pages 273-277
Published: December 25, 2012
Released on J-STAGE: March 08, 2013
JOURNAL FREE ACCESSWe evaluated the sensitivity and specificity of an immunochromatography kit, Single-path Emetic Tox Mrk (Merck), which targets a marker protein for the detection of Bacillus cereus that produces emetic toxin. Strains were isolated after outbreaks of food poisoning, and from retail prepared foods and food products. The strains were examined for the presence of the emetic toxin-synthetase gene by PCR. All 58 emetic strains isolated from the food poisoning cases showed a positive reaction in the immunochromatography kit. No emetic strains gave false negative result. Among 47 non-emetic strains, only two strains isolated from the food poisonings and one strain isolated from food products showed a false positive reaction in the test. We concluded that this method has high sensitivity and specificity. The test can be used for detection of emetic toxin-producing B. cereus not only from food poisoning cases, but also in food products.View full abstractDownload PDF (725K)
Validation Study
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Katsushige URANISHI, Hirokazu YAMASHITA, Akiko OKAYAMA, Keigo YAMAMOTOArticle type: Validiation Study
2012 Volume 53 Issue 6 Pages 278-290
Published: December 25, 2012
Released on J-STAGE: March 08, 2013
JOURNAL FREE ACCESSSupercritical fluid extraction (SFE) was applied to extraction of pesticides from cereals and pulses. Residues were extracted from homogenized samples mixed with water-absorbent polymer and supercritical carbon dioxide in a stainless steel tube, followed by elution with acetonitrile. Co-extractives were removed by means of mini-column clean-up. Measurement was performed by GC-MS/MS. Calibration was achieved by preparing matrix-matched calibration standards to counteract matrix effects. With the Japanese method validation guideline for pesticide residues as a reference, the method was assessed in 5 agricultural products spiked with 334 pesticides at 0.01 and 0.1 µg/g. Compounds at each level were extracted from 2 samples on 5 separate days. The trueness of the method for 137 pesticides in all samples was 70–120%, and the repeatability and within-run reproducibility were also consistent with the guideline. The trueness of the method for the other 101 pesticides was in the range of 50–70%, though the repeatability and within-run reproducibility were satisfactory. This method is available as a multiresidue analysis method for cereals and pulses.View full abstractDownload PDF (791K)
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