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Volume 44 (2003)
- Issue 6 Pages 269-
- Issue 5 Pages 213-
- Issue 4 Pages 181-
- Issue 3 Pages 145-
- Issue 2 Pages 77-
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Volume 44, Issue 6
Displaying 1-10 of 10 articles from this issue
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Review
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Takashi SUZUKI2003 Volume 44 Issue 6 Pages 269-280
Published: December 25, 2003
Released on J-STAGE: January 21, 2009
JOURNAL FREE ACCESSDownload PDF (1318K)
Originals
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Takahiro WATANABE, Kikuko KASAMA, Chiseko WAKUI, Masaaki SHIBUYA, Akih ...2003 Volume 44 Issue 6 Pages 281-288
Published: December 25, 2003
Released on J-STAGE: January 21, 2009
JOURNAL FREE ACCESSTo investigate the key factors affecting the reliability of the analytical results, a laboratory-performance study was attempted for the notified methods to detect genetically modified (GM) maize (CBH351) and GM potato (NewLeaf Plus and NewLeaf Y). The test samples were designed as three pairs of blind duplicates, which included 0%, 0.1% and 1.0% GM maize (CBH351) or GM potato (NewLeaf Plus or NewLeaf Y). Fourteen laboratories participated in the study. The test samples were sent to the participating laboratories along with the protocol. The data were collected from all laboratories and statistically analyzed. For the 0% sample of the CBH351 maize, one laboratory reported a false-positive result. It was considered that contamination could have occurred via the common use of equipment or tools for the test. For the 0.1% samples of the NewLeaf Plus potato or NewLeaf Y potato, on the other hand, three laboratories reported false-negative results. It was presumed that these results were due to changes of the conditions of the electrophoresis and agarose-gel staining. The other laboratories reported appropriate results. It was considered that the method employed in this study was suitable for the assessment of laboratory performance.View full abstractDownload PDF (1068K) -
Norinaga MIWA, Tomohiro NISHIO, Yono ARITA, Fumihiko KAWAMORI, Takashi ...2003 Volume 44 Issue 6 Pages 289-293
Published: December 25, 2003
Released on J-STAGE: January 21, 2009
JOURNAL FREE ACCESSVibrio parahaemolyticus densities in spiked and naturally contaminated seafood samples were enumerated by the MPN method combined with a PCR procedure (MPN-PCR method) targeting the species-specific thermolabile hemolysin gene (tlh), and by the MPN method using subcultivation of alkaline-peptone-water (APW) enrichment culture on thiosulfate-citrate-bile-sucrose (TCBS) agar (MPN-TCBS method). In the samples spiked with both V. parahaemolyticus and V. alginolyticus, the numbers of V. parahaemolyticus enumerated by the MPN-PCR method were similar to, or higher than the numbers of spiked cells, whereas those enumerated by the MPN-TCBS method were below the numbers of spiked cells. In naturally contaminated seafood samples, the numbers of V. parahaemolyticus enumerated by the MPN-PCR method were higher than those by the MPN-TCBS method. In the case of the MPN-TCBS method, isolation of V. parahaemolyticus from some APW cultures was difficult because of the overgrowth of many colonies other than V. parahaemolyticus (e.g., V. alginolyticus) on TCBS agar. In contrast, the PCR technique could detect tlh from APW culture without isolation of V. parahaemolyticus, so the possibility of failing to obtain a positive result in APW culture by the MPN-PCR method was considered to be lower than that by the MPN-TCBS method. Furthermore, utilization of the PCR technique reduces the time and labor required for the biochemical identification tests used in the MPN-TCBS method. For the detection and enumeration of V. parahaemolyticus in seafood, especially for samples that show many colonies other than V. parahaemolyticus on TCBS agar, the MPN-PCR method may be more convenient and reliable than the MPN-TCBS method.View full abstractDownload PDF (147K) -
Yoshiaki AMAKURA, Tomoaki TSUTSUMI, Kumiko SASAKI, Tamio MAITANI2003 Volume 44 Issue 6 Pages 294-302
Published: December 25, 2003
Released on J-STAGE: January 21, 2009
JOURNAL FREE ACCESSTo evaluate dioxin contamination in retail vegetables, congener analyses of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and coplanar polychlorinated biphenyls (Co-PCBs) were performed on sixty varieties of fresh vegetables including cereals and mushrooms, obtained from Japanese supermarkets in 2002. The toxic equivalent quantity (TEQ) levels for dioxins in samples ranged from <0.001 to 0.089 pg-TEQ/g wet weight, when undetected and trace were taken as zero. Among the samples, dioxins were generally detected in green leafy vegetables. The highest TEQ value was for mulukhiya (0.089 pg-TEQ/g), followed by spinach and komatsuna (Japanese mustard spinach) (0.077 and 0.074 pg-TEQ/g, respectively). Additionally, the dioxin levels in seventeen varieties of frozen vegetables were also determined, and showed TEQ values ranging from<0.001 to 0.080 pg-TEQ/g. The total TEQ in commercial vegetables mainly reflected the levels of 1,2,3,7,8-PeCDD, 2,3,4,7,8-PeCDF and 3,3',4,4',5-PeCB (#126) (the sum of them represented 63% of the total TEQ).View full abstractDownload PDF (624K) -
Hisaya TERADA, Yukio TAMURA2003 Volume 44 Issue 6 Pages 303-309
Published: December 25, 2003
Released on J-STAGE: January 21, 2009
JOURNAL FREE ACCESSA simple and convenient analytical method for the determination of acrylamide in processed foods was established. Acrylamide was extracted with water in an ultrasonic bath. The extract was passed through an OASIS HLB cartridge and the eluate was injected into the HPLC system using a column-switching technique. The HPLC system consisted of two pumps, two 6-port-2-position valves, two columns and a UV detector. At first, the sample solution was chromatographed on an ODS column with a mobile phase of water, then the flow of the mobile phase was switched using a 6-port-2-position valve, and the acrylamide peak fraction was introduced into an aqueous gel permeation column (analytical column). The fraction was chromatographed again on the analytical column with a mobile phase of water, and the eluate was monitored with a UV detector (205 nm).
The recoveries of acrylamide from potato chips, fried potato, croquette and instant noodle fortified at levels of 50 to 1,000 μg/kg were 93.1 to 101.5% and the coefficient of variation was 1.5 to 5.2%. The detection limit corresponded to 10 μg/kg in processed foods.
Forty-six samples, potato chips (11), fried potato (10), croquette (20) and instant noodle (5), were analyzed by this method. The acrylamide level was 67-4,499 μg/kg for potato chips, 125-1,183 μg/kg for fried potato, nd-255 μg/kg for croquette and nd-151 μg/kg for instant noodle.View full abstractDownload PDF (697K) -
Tomoko INOUE, Saori SASAKI, Seiji UCHIKAWA, Yoshichika HIRAHARA, Yukih ...2003 Volume 44 Issue 6 Pages 310-315
Published: December 25, 2003
Released on J-STAGE: January 21, 2009
JOURNAL FREE ACCESSThe objective of this study was to elucidate the utility of ion-trap GC/MS/MS for the analysis of pesticides in extracted matrices from various agricultural products. Identification and quantitative analysis of pesticides in matrices were performed by quadrupole GC/MS and ion-trap GC/MS/MS. Chlorpyrifos was added to the matrix of spinach, soybean in the pod or corn, and aldrin, dieldrin, endrin, α-BHC, β-BHC, γ-BHC, δ-BHC, p,p'-DDD, p,p'-DDE, o,p'-DDT and p,p'-DDT were added to each matrix of green tea, black tea or oolong tea. Although most of the pesticides in the matrix could not be determined by quadrupole GC/MS-Scan analysis at 0.1 μg/mL, every pesticide was identified from the mass spectrum using ion-trap GC/MS/MS at the same concentration. The quantitation limit of every pesticide in each matrix by ion-trap GC/MS/MS analysis was higher than that by GC/MS-SIM analysis. The calibration curves obtained by GC/MS/MS were linear in the range of 0.01-0.25 μg/mL of each pesticide. The recoveries of each pesticide from four kinds of samples spiked at the levels of 0.01 ppm to 0.02 ppm in extracts were 61.2-138.3% with SD values in the range from 1.2 to 15.4%. This study revealed that ion-trap GC/MS/MS was useful for the identification and quantitative analysis of low-level pesticides residues in matrices of agricultural products.View full abstractDownload PDF (583K) -
Yoshiaki AMAKURA, Tomoaki TSUTSUMI, Kumiko SASAKI, Tamio MAITANI2003 Volume 44 Issue 6 Pages 316-320
Published: December 25, 2003
Released on J-STAGE: January 21, 2009
JOURNAL FREE ACCESSWe determined the concentrations of polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs) and coplanar polychlorinated biphenyls (Co-PCBs) in three types of fast foods [(1) seventeen hamburgers and two hot dogs, (2) six portions of fried potatoes and (3) three chicken products] obtained from fast food shops or convenience stores in Japan. All samples tested showed low toxic equivalent quantity (TEQ) levels of dioxins in the range of 0.001-0.083 pg-TEQ/g wet weight (0.006-0.053 pg-TEQ/g for hamburgers and hot dogs, 0.001-0.083 pg-TEQ/g for fried potatoes and 0.053-0.065 pg-TEQ/g for chicken products). The congener profile in hamburgers and hot dogs suggested that the total TEQ was mainly determined by Co-PCBs, especially by 3,3',4,4',5-PeCB (#126), which accounted for 44% of the total TEQ value. Findings for animal foods such as beef and cheese were consistent with this result. For fried potatoes, PCDD/Fs accounted for 94% of the total TEQ value, and 2,3,4,7,8-PeCDF accounted for 32% of PCDD/Fs. Dioxins in the chicken products consisted of 3,3',4,4',5-PeCB (#126) and 1,2,3,7,8-PeCDD, which accounted for 23% and 21% of the total TEQ, respectively. If an adult (50 kg weight) eats 150 g of hamburger, 100 g of potatoes and 150 g of chicken, the daily intake is estimated to be 0.299 pg-TEQ/kg b.w./day using the average values (0.022, 0.028 and 0.059 pg-TEQ/g, respectively) obtained in this study. This value corresponds to 7.5% of the tolerable daily intake (TDI) for PCDD/Fs and Co-PCBs in Japan.View full abstractDownload PDF (299K) -
Yoshiaki AMAKURA, Tomoaki TSUTSUMI, Kumiko SASAKI, Tamio MAITANI2003 Volume 44 Issue 6 Pages 321-327
Published: December 25, 2003
Released on J-STAGE: January 21, 2009
JOURNAL FREE ACCESSTo determine polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and coplanar polychlorinated biphenyls (Co-PCBs) in green leafy vegetables, the cleanup method was modified, and packing methods for a multi-layer silica gel column were compared in food samples. First, the additional cleanup was examined for a mono-ortho PCBs fraction obtained by alumina column chromatography from spinach extract. Small solids such as rough crystals that remained after concentration of the mono-ortho PCBs fraction were identified as long-chain hydrocarbons from leaf epicuticular wax by GC/MS. Cleanup using an activated carbon silica gel column with n-hexane as the washing solvent was effective. Next, multi-layer silica gel columns packed by wet packing and dry packing were compared using komatsuna, salmon and butter as samples. The columns prepared by both methods gave similar values at each isomeric concentration level and showed similar efficiency with favorable recoveries.View full abstractDownload PDF (1156K)
Notes
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Naoki SUGIMOTO, Kyoko SATO, Takeshi YAMAZAKI, Kenichi TANAMOTO2003 Volume 44 Issue 6 Pages 328-331
Published: December 25, 2003
Released on J-STAGE: January 21, 2009
JOURNAL FREE ACCESSJamaica quassia extract, a natural bittering agent, is described as “a substance extracted from bark of Jamaica quassia (Quassia excelsa SW.)” in the List of Existing Food Additives in Japan. The constituents in Jamaica quassia extract product were investigated as a part of an ongoing study to evaluate its quality and safety as a food additive. The main constituents of the extract were identified as quassin and two isomers of neoquassin by using LC/MS. The main constituent, quassin, was isolated and the structure was determined by spectral means. The quantification of their main constituents was performed by HPLC using quassin as a standard, and the concentrations of quassin and total of neoquassin isomers were 21.4% and 55.5%. In addition, it was confirmed that Jamaica quassia extract was different from quassia extract, which is extracted from bark of Picrasma quassioides BENN. belonging to the same family as Q. excelsa, by comparing their HPLC profiles.View full abstractDownload PDF (440K) -
Hiroyuki OHNO, Masako SUZUKI, Taiki AOYAMA, Kazunori MITANI2003 Volume 44 Issue 6 Pages 332-336
Published: December 25, 2003
Released on J-STAGE: January 21, 2009
JOURNAL FREE ACCESSAn improved migration test was developed for determination of trace amounts of epichlorohydrin from internal can coatings. Eight kinds of sample cans, coated mainly with epoxy resin, for foods and beverages were prepared, and both their bodies and lids were tested for migration as follows. A body was filled with n-pentane and soaked for 2 hours at 25°C. A lid was soaked in n-pentane (2 mL/cm2) for 2 hours at 25°C. The test solution was analyzed by GC-FID and GC/MS using two DB-WAX capillary columns with different inside diameters. The limits of quantitation were 0.05 μg/mL by GC-FID and 0.02 μg/mL by GC/MS with selected ion monitoring. Recoveries of spiked epichlorohydrin were 99.9-104.5% at the level of 0.05 μg/mL and 0.5 μg/mL, with high precision. In this study, no epichlorohydrin was found to have migrated from any of the bodies and lids.View full abstractDownload PDF (528K)
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