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Volume 52, Issue 1
Displaying 1-13 of 13 articles from this issue
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Review
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Reiko TESHIMA, Ryosuke NAKAMURA2011 Volume 52 Issue 1 Pages 1-9
Published: February 25, 2011
Released on J-STAGE: March 04, 2011
JOURNAL FREE ACCESSDownload PDF (1656K)
Original Papers
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Motoh MUTSUGA, Michiyo YOTSUYANAGI, Yoko KAWAMURA2011 Volume 52 Issue 1 Pages 10-17
Published: February 25, 2011
Released on J-STAGE: March 04, 2011
JOURNAL FREE ACCESSWe compared test methods for measurement of lead in metal utensils using flame-atomic absorption spectroscopy (AAS), graphite furnace-AAS (GFAA), inductively coupled plasma atomic emission spectrometry (ICP) and X-ray fluorescence analysis (XRF). The procedure for preparation of the test solution was improved. A 100 mg of sample was dissolved in 2.5 mL of HCl and HNO3 (3 : 1) mixture (in the case of titanium sample, dissolved in HCl). Stock solution was prepared by diluting to 50 mL with water. The test solution was prepared by diluting with 0.1 mol/L HNO3. The recoveries of lead added to various kinds of metal reagent at the level of 0.1% were 90-118%. When standard materials which contained lead at the level of 0.0098-0.11% were measured, the measured values were in close agreement with the standard values. These procedures are applicable to aluminum, iron, stainless steel, copper, tin and titanium products. The AAS method, GFAA method and ICP method were suitable as the lead test methods. Moreover, the XRF method was useful as a screening method or a simple determination method. The ICP method was used to determine the lead contents in 22 kinds of commercial metal utensils, and 0.011-0.040% of lead were detected in 6 samples.View full abstractDownload PDF (1014K) -
Hiroshi SAKABE, Yoshitane MORI, Kimie SAITOU, Setsuko TODORIKI2011 Volume 52 Issue 1 Pages 18-23
Published: February 25, 2011
Released on J-STAGE: March 04, 2011
JOURNAL FREE ACCESSThe thermoluminescence (TL) method using X-rays was investigated for the purpose of detection of irradiated food, and the method was validated at a single laboratory level. A small X-ray irradiator was developed as an alternative radiation source for normalization, and X-ray irradiation conditions equivalent to gamma-ray irradiation from 60Co were established. Gamma-ray irradiated spices were used for the method validation. The detection limits (MDL) and lower limit of integrated TL intensities (MDL×10) for the spices were checked and the separation of silicate minerals from the spices was confirmed to be sufficient for TL analysis. There was no significant difference in TL glow ratio obtained using two sets of X-ray irradiation equipment including the newly developed equipment. Repeatability and intermediate precision showed no influence of analysts, X-ray irradiation equipments, or measurement days on the TL ratios. From these results, this detection method was validated in a single laboratory.View full abstractDownload PDF (1428K) -
Naoki SHINODA, Yoshiyasu HASHIMOTO, Masami TAKAGI, Fumio KOJIMA, Takas ...2011 Volume 52 Issue 1 Pages 24-27
Published: February 25, 2011
Released on J-STAGE: March 04, 2011
JOURNAL FREE ACCESSA method for confirming identification of prohibited species tissue in animal feed has been developed on the basis of PCR-RFLP analysis. In Japan, to prevent the spread of BSE through animal feed, the use of animal protein in feed has been regulated. Species-specific PCR detection of prohibited species materials in feed has been used as one of a series of laboratory tests to ensure the proper implementation of the feed regulations. However, since the result of this PCR method is determined only by amplicon length, it is sometimes necessary to confirm whether or not the positive result is due to the effect of a non-specific reaction. For this purpose, DNA sequencing is the best way to confirm the test result but it is not suitable for routine analysis because of the required time and cost. In this study, we developed an easy and rapid method to confirm the species identification (mammals, ruminants and cattle) by using 4 restriction enzymes: SmlI, MboI, BlnI and Hpy188III. This PCR-RFLP method, which ensures identification of prohibited animal species in feed, is useful for enhancing the reliability of feed inspection for BSE prevention. This method will be added to the Official Methods of Feed Analysis.View full abstractDownload PDF (644K) -
Shigemi KAI, Takeshi AKABOSHI, Masumi WAKI, Teruhisa FUZIMAKI, Hideko ...2011 Volume 52 Issue 1 Pages 28-33
Published: February 25, 2011
Released on J-STAGE: March 04, 2011
JOURNAL FREE ACCESSA method for simultaneous determination of metribuzin (MET) and three metribuzin metabolites in livestock products and seafoods by liquid chromatography-tandem mass spectrometry (LC-MS/MS) was developed. MET and its metabolites were extracted from a sample with acetonitrile, followed by InertSepC18 and BondElut SAX cartridge cleanup. The LC separation was performed on a C18 column using 0.01 mol/L ammonium formate-acetonitrile-methanol (70 :21 : 9) as the mobile phase and MS detection with both positive and negative ion electrospray ionization. The mean recoveries from 10 livestock products and seafoods were generally >60%, and the relative standard deviations were <20%View full abstractDownload PDF (577K)
Notes
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Rie ISHII, Kunihiko TAKAHASHI, Ryuji MATSUMOTO2011 Volume 52 Issue 1 Pages 34-39
Published: February 25, 2011
Released on J-STAGE: March 04, 2011
JOURNAL FREE ACCESSA simple method using high-performance liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) was investigated for the detection of the antiprotozoal drug imidocarb in 10 livestock and seafood products. Liquid chromatographic separation employed a TSK VMpak-25 column with ammonium acetate-acetonitrile as a mobile phase. Mass spectral acquisition was performed in the ESI positive-ion mode. Imidocarb was extracted from all samples using liquid extraction with acetonitrile under basic conditions. For samples other than honey, fat-soluble impurities were removed by acetonitrile-hexane partitioning. The salting-out technique was used for extraction from honey in order to improve the separation of the organic solvent and water added to the honey sample. The limit of quantitation was 0.005 μg/g (expressed as concentration in samples). The recoveries from all samples were 76-109%, and the repeatability and reproducibility were also satisfactory.View full abstractDownload PDF (828K) -
Takumi AKIYAMA, Takeshi YAMAZAKI, Kenichi TANAMOTO2011 Volume 52 Issue 1 Pages 40-46
Published: February 25, 2011
Released on J-STAGE: March 04, 2011
JOURNAL FREE ACCESSThe identification test for thickening polysaccharides containing neutral saccharides and uronic acids was investigated by GC analysis of constituent monosaccharides. The reported method, in which monosaccharides were converted to diethyldithioacetal derivatives with ethanethiol followed by trimethylsilylation, was improved in terms of operability and reproducibility of GC/MS analysis. The suitability of the improved diethyldithioacetal derivatization method was determined for seven thickening polysaccharides, i.e., carob bean gum, guar gum, karaya gum, gum arabic, gum ghatti, tragacanth gum and peach gum. The samples were acid-hydrolyzed to form monosaccharides. The hydrolysates were derivatized and analyzed with GC/FID. Each sugar derivative was detected as a single peak and was well separated from others on the chromatograms. The amounts of constituent monosaccharides in thickening polysaccharides were successfully estimated. Seven polysaccharides were distinguished from each other on the basis of constituent monosaccharides. Further examination of the time period of hydrolysis of polysaccharides using peach gum showed that the optimal times were not the same for all monosaccharides. A longer time was needed to hydrolyze glucuronic acid than neutral saccharides. The findings suggest that hydrolysis time may sometimes affect the analytical results on composition of constituent monosaccharides in polysaccharides.View full abstractDownload PDF (1093K) -
Kunihiko TAKAHASHI, Ryuji MATSUMOTO, Satoru NEMOTO, Rieko MATSUDA2011 Volume 52 Issue 1 Pages 47-50
Published: February 25, 2011
Released on J-STAGE: March 04, 2011
JOURNAL FREE ACCESSA 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 re-extracted 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 methanol-water (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 0.002-0.2 μg/mL of hydramethylnon. Recoveries (n=5) of hydromethylnon from 10 kinds of agricultural products fortified at 0.01 μg/g (0.05 μg/g for pineapple) were 82-110%, and their relative standard deviations were 2-12%.View full abstractDownload PDF (775K) -
Miho SAKAMOTO, Kazue TAKEBA, Takeo SASAMOTO, Tomoko KUSANO, Hiroshi HA ...2011 Volume 52 Issue 1 Pages 51-58
Published: February 25, 2011
Released on J-STAGE: March 04, 2011
JOURNAL FREE ACCESSA liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) method was developed to determine the residues of dimetridazole (DMZ), metronidazole (MNZ) and ronidazole (RNZ) in salmon and honey. These compounds were extracted with ethyl acetate from samples and cleaned up using a silica solid phase extraction (SPE) cartridge. These compounds were determined by reversed-phase LC using a C18 column with distilled water-methanol as the mobile phase, and MS detection in the positive mode by applying selected reaction monitoring (SRM). DMZ-d3, MNZ-13C2,15N2 and RNZ-d3 were used as internal standards. The method was validated in salmon and honey spiked with these compounds at 0.4-2 μg/kg, and average recoveries were in the range of 91.2-107.0%. Repeatability was 1.7-17.1% and intermediate precision was less than 20%. The detection limits of DMZ, MNZ and RNZ in salmon and honey were 0.05-0.2 μg/kg. The method was applied to 3 salmon and 20 honey samples. The concentrations of these compounds in all samples were lower than the detection limits established by the Ministry of Health, Labour and Welfare in Japan.View full abstractDownload PDF (771K) -
Emiko YOSHIDA, Takahiro SHIBUYA, Chieko KUROKAWA, Yutaka INOUE, Yoshih ...2011 Volume 52 Issue 1 Pages 59-65
Published: February 25, 2011
Released on J-STAGE: March 04, 2011
JOURNAL FREE ACCESSDevelopment of rapid and high accuracy analysis, and tightening of regulations for veterinary drugs are required because many examples of detection of veterinary drugs in many kinds of processed food have been reported. In this study, we constructed an improved method for simultaneous determination of veterinary drugs, based on the glass bead homogenization method with EDTA-2Na and batch purification for QuEChERS analysis. Our extraction procedure is suitable for handling multiple samples quickly and easily. Furthermore, our improved extraction solvent allowed simultaneous determination of tetracyclines in processed food. In a test of 69 veterinary drugs, recovery of over 60 ranged from 70 to 120%, with a coefficient of variation of less than 25% and with quantification limits of 0.01 μg/g (S/N≥10 ). This improved method is expected to be useful for quick simultaneous determination of multiple residues.View full abstractDownload PDF (927K) -
Hiroyuki OHNO, Masako SUZUKI, Yoko KAWAMURA2011 Volume 52 Issue 1 Pages 66-70
Published: February 25, 2011
Released on J-STAGE: March 04, 2011
JOURNAL FREE ACCESSThe amount of evaporation residue was investigated as an index of total amount of non-volatile substances that migrated from plastic kitchen utensils into four food-simulating solvents (water, 4% acetic acid, 20% ethanol and heptane). The samples were 71 products made of 12 types of plastics for food contact use. The amount was determined in accordance with the Japanese testing method. The quantitation limit was 5 μg/mL. In the cases of polyethylene, polypropylene, polystyrene, acrylonitrile styrene resin, acrylonitrile butadiene styrene resin, polyvinyl chloride, polyvinylidene chloride, polymethylpentene, polymethylmethacrylate and polyethylene terephthalate samples, the amount was highest for heptane and very low for the other solvents. On the other hand, in the cases of melamine resin and polyamide samples, the amount was highest for 4% acetic acid or 20% ethanol and lowest for heptane. These results enabled the selection of the most suitable solvent, and the rapid and efficient determination of evaporation residue.View full abstractDownload PDF (692K)
Reports
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Hiroko WATANABE, Chie AKABOSHI, Kiyotaka SAITA, Haruko SEKIDO, Shigeki ...2011 Volume 52 Issue 1 Pages 71-77
Published: February 25, 2011
Released on J-STAGE: March 04, 2011
JOURNAL FREE ACCESSThe old ELISA method for detection of allergenic substances (egg and milk) in Kanagawa prefecture from 2003 to 2007, employed before improvement of the food allergen labeling system, yielded detection rates of 20% for egg and 30% for milk. In 2005, after improvement of the labeling system, the detection rate using the new ELISA in solutions containing 1% SDS and 7% 2-mercaptoethanol increased by about 10% for egg, but decreased by half for milk. There were 4 positive samples (over 10 μg/g) for both egg and milk proteins, on account of contamination by ingredients at the manufacturing line and the lack of proper food labeling. In 2009, the contamination levels of egg and milk proteins in labeled commercial foods were low. In a comparison between the new and old methods with the same samples, both the new ELISA and Western-blot analyses showed an increase in the detection rate of egg protein. In relation to milk protein, the detection rates were decreased with the new ELISA, although the ELISA detection rate and consistency rates with Western-blot analysis were increased. On the other hand, in the case of a protein content below 5 μg/g, it was impossible to determine ovomucoid and casein by Western-blot analysis.View full abstractDownload PDF (840K) -
Satoshi TAKATSUKI, Takahiro WATANABE, Rieko MATSUDA2011 Volume 52 Issue 1 Pages 78-85
Published: February 25, 2011
Released on J-STAGE: March 04, 2011
JOURNAL FREE ACCESSPerchlorate, which may be naturally occurring or artificial in origin, inhibits iodide uptake into the thyroid gland and disturbs thyroid function. In order to investigate perchlorate contamination in foods in Japan, perchlorate levels in 28 wine samples, 20 seafood samples, 10 polished rice samples, 30 milk (include whole milk, composition modified milk, low fat milk, processed milk, milk drink) samples, 10 powdered milk samples and 10 yogurt samples were measured. Perchlorate was found in all wine, milk, powdered milk and yogurt samples tested. Perchlorate levels ranged from 0.2 ng/g to 103 ng/g in wine samples, from 2 ng/g to 11 ng/g in milk samples, from 3 ng/g to 35 ng/g in powdered milk samples, and from 2 ng/g to 11 ng/g in yogurt samples. Perchlorate levels in the seafood samples were under the LOQ (0.8 ng/g) in 8 samples and ranged from 0.8 ng/g to 72 ng/g in 12 samples. In all polished rice samples, perchlorate level was under the LOQ (1.0 ng/g).View full abstractDownload PDF (1086K)
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