Estimated daily intake of plasticizers in 1-week duplicate diet samples following regulation of DEHP-containing PVC gloves in Japan

Duplicate hospital diet samples obtained over 1 week in 2001 were analysed to estimate the daily intake of plasticizers and the results were compared with those obtained in 1999. The plasticizers quantified in this study were: dibutyl phthalate, butylbenzyl phthalate (BBP), di(2-ethylhexyl) phthalate (DEHP), diisononyl phthalate (DINP), di(2-ethylhexyl) adipate (DEHA), diisononyl adipate (DINA) and O-acetyl tributyl citrate (ATBC). Dipropyl, dipentyl, dihexyl and dicyclohexyl phthalate were also analysed but not detected. The analytical procedure for this follow-up study was essentially the same as in the previous one. Detection limits were 0.1-15.6 ng g(-1) for each plasticizer. One-week duplicate diet samples provided by three hospitals in three remote prefectures of Japan were analysed as individual meals. DEHP was detected at 6-675 ng g(-1) in 62 of 63 meals, significantly lower levels compared with those detected in 1999. Levels of DEHA and DINP also decreased. The mean intake of plasticizers estimated from all samples was 160 microg DEHP day(-1), 12.5 microg DEHA day(-1), 4.7 microg DINP day(-1) and 3.4 microg BBP day(-1). Levels of DINA were relatively high in meals from one hospital: in those meals, the average daily intake was 1338 microg day(-1). Those of ATBC were also higher in meals from another hospital: the average daily intake was 1228 microg day(-1). The sources of DINA and ATBC can be cling-film or sausage packaging.

[Estimated production by the official inspection of tar colors (including aluminum lakes) in fiscal year 2000]

There were 176 official inspections of tar colors and their lakes in fiscal year 2000, and 175 samples were qualified. The quantity of tar colors that passed inspection in Japan in fiscal year 2000 reached 137.5 tons. Tar color production is estimated by month and by manufacturer. The food tar color produced in the largest quantity was Food Yellow No. 4, accounting for 43.4% during this period.

[Studies on rejected food yellow no. 5 (sunset yellow FCF) aluminum lake]

One out of two sunset yellow FCF aluminum lakes (Y-5Als) did not comply with the specifications in JSFA-VII in the official inspection of tar colors in fiscal year 2000. A sub-spot was detected in the paper chromatography test. This rejected sample was analyzed by HPLC for the subsidiary color, raw materials and intermEdiates in Y-5. The sub-spot was identified as sulfanilic acid azo R salt color, and its content was estimated at 4.5% as the content of Y-5 in Y-5Al being 100.0%.

[Studies on rejected food blue no. 1 (Brilliant Blue FCF) aluminum lake]

One of the brilliant blue FCF aluminum lakes (B-1Als) in the official inspection of coal-tar dyes in fiscal year 1999 was rejected. The results of tests of the rejected sample were submitted to JSFA-VII except for a violet sub-spot by paper chromatography. Its visual spectrum had same lambda max 630 nm as B-1 standard and a very small shoulder at 580 nm in comparing to B-1 standard. HPLCs detected at 625 nm of subsidiary dyes and 580 nm were performed on the rejected sample of B-1Al. A sub-V in HPLCs of th sample which eluted at 37.6 min had its relative peak area of 7.9% at 580 nm and 0.24% at 625 nm, and its peak ratio (at 580 nm/at 625 nm) was extremely large. Consequently, it was presumed that the sub-V in those HPLCs corresponded to the violet sub-spot in paper chromatography.

[Estimated production by the official inspection of coal-tar dyes (including dye aluminum lakes) in fiscal year 1999]

There were 260 official inspections of coal-tar dyes and their lakes in fiscal year 1999, and 259 of the lots qualified, one of the 8 samples of Food Blue No. 1 aluminum lakes was rejected. The quantity of coal-tar dyes that passed inspection in Japan in fiscal year 1999 reached 151.9 tons. Coal-tar dye production is estimated by month and by manufacturer. The food coal-tar dye produced in the largest quantity was Food Yellow No. 4, accounting for 44.2% during this period.

[Studies on procedure for sample preparation of ellagic acid in several kinds of foodstuffs]

A sample preparation for ellagic acid in several kinds of foodstuffs, which is included in the List of Existing Food Additives as natural antioxidants in Japan, functioning as an antioxidant, was studied. The solid samples were refluxed with methanol, and then the extract was refined using a solid-phase cartridge. The liquid samples were directly pretreated by solid-phase extraction. On the other hand, test solutions for cooking oils and fats were inapplicable to solid-phase extraction in this work, because the recovery tests from samples spiked with ellagic acid gave low recoveries. Consequently, they were prepared by modified frozen method using methanol or acetonitrile-2-propanol-ethanol (2:1:1). The recoveries from tested foodstuffs spiked with ellagic acid (50 micrograms/g) were 75.2-96.9%. The limits of quantification for ellagic acid were 0.05 microgram/g by the proposed method.

[Clean-up procedure with ion-exchange mini column in the analysis of flusulfamide in agricultural products by HPLC]

A clean-up procedure with an ion-exchange column in the analysis of flusulfamide by HPLC was examined. Pesticide in the sample was extracted with methanol following liquid-liquid partition with ethyl acetate. The ethyl acetate fraction was cleaned up with silica gel column chromatography. The eluate from the silica gel column was further cleaned up with SAX + PSA mini column, then determined by HPLC. Carotenoids and interfering peaks were removed by washing the combined mini columns with 10 mL of 20% acetone-containing n-hexane and 5 mL of acetone, and flusulfamide was eluted with 35 mL of acetone.

[Preparation of HPLC test solutions for organic impurities in aluminum lakes of food red no. 40 (allura red AC) and food yellow no. 5 (sunset yellow FCF)]

The HPLC determination of organic impurities in Food Red No. 40 aluminum lakes (R-40Als) as directed by Japan's Specifications and Standards for Food Additives, 7th Ed. (JSFA-VII), has problems, such as reproducibility and low recovery. ICP analyses suggested that the problem was caused by the aluminum in the test solution. In the improved method for preparation of the test solution, aluminum was precipitated as a hydroxide gel by boiling with 1% aqueous ammonia. After centrifugation, the supernatant was used for the HPLC analysis of the organic impurities in the lakes. Recoveries of organic impurities were more than 85% from R-40Al spiked at the 0.1 and 1.0% levels of R-40. The proposed method was also adapted for Food Yellow No. 5 aluminum lakes.

Structural determination of the subsidiary colors in food blue No. 1 (brilliant blue FCF) aluminum lake detected by paper chromatography

One of eight Food Blue No. 1 aluminum lakes (B-1Als) used in the official inspection of coal-tar colors in fiscal year 1999 had a violet sub-spot during paper chromatography and was rejected. To clarify the orgin of the sub-spot, the violet subsidiary color (Sub-V) was isolated from the sample. On the basis of NMR and MS analyses and ion chromatography, the structure of the subsidiary color was elucidated to be 2-[[4-[N-ethyl-N-(3- sulfophenylmethyl)amino]phenyl][4-hydroxyphenyl]methylio]benzenesulfonic acid. The relative content of Sub-V to that of m,m-B-1 in the rejected sample was determined to be 39.5% by HPLC. The relative contents in other submitted samples of B-1Al were in the range of 1.1-3.6%.

Determination of clethodim and its oxidation metabolites in crops by liquid chromatography with confirmation by LC/MS

A method was developed for determination of the herbicide clethodim (C0) and its oxidation metabolites clethodim sulfoxide (C1) and clethodim sulfone (C2) in agricultural products. Upon extraction, both C0 and C1 were oxidized to C2 by m-chloroperoxybenzoic acid, and C2 was determined by liquid chromatography (LC). The C2 peak was confirmed by liquid chromatography/mass spectrometry (LC/MS) with electrospray ionization (ESI). Recoveries of C0 from radish, tomato, onion, sweet potato, kidney bean, carrot, cabbage, and lettuce ranged from 91 to 118% following fortification at 0.05-1.0 ppm. The detection limit of C2 in crops was 0.01 ppm (S/N > 3). The fortified samples of onion, sweet potato, kidney bean, and carrot were confirmed by LC/MS (ESI), and the peak of C2 was detected.

Di(2-ethylhexyl) phthalate contamination of retail packed lunches caused by PVC gloves used in the preparation of foods

Plasticizer contamination of foods sold in retail packed lunches and set lunches in restaurants was determined by GC/MS. The phthalate esters were as follows: diethyl, dipropyl, dibutyl, dipentyl, dihexyl, butylbenzyl, dicyclohexyl, di(2-ethylhexyl), dioctyl, diisooctyl (mixture of isomers) and diisononyl (mixture). Di(2-ethylhexyl) adipate was also determined. Sixteen packed lunches and ten set lunches were analysed, and in all samples the concentration of di(2-ethylhexyl) phthalate (DEHP) was the highest, at 0.80-11.8 mg/kg in packed lunches and 0.012-0.30 mg/kg in set lunches. The DEHP content of five packed lunches exceeded 1.85 mg, which is the EU tolerable daily intake (TDI) for a person of 50 kg body weight. Foodstuffs that were components of the packed lunches were taken from the factory at each step of preparation and phthalates were determined. For example, chicken contained 0.08 mg/kg DEHP when uncooked, 13.1 mg/kg after frying and 16.9 mg/kg after packing. Disposable PVC gloves used in the preparation of foods were apparently the source of high DEHP concentrations. The gloves used during cooking or packaging were sprayed with 68% (w/w) ethanol to sterilize them. PVC gloves from the factory contained 22 or 41% by weight of DEHP. To confirm the link with the contamination problem, samples of boiled rice, croquette and boiled dry radish were handled in the laboratory with PVC gloves containing 30% (w/w) DEHP. DEHP migration levels of 0.05 mg/kg in rice or 0.33 mg/kg in croquette, and 11.1 mg/kg in radish were found. The alcohol sprayed onto the gloves increased the migration of DEHP to 2.03 mg/kg in rice, 2.45 mg, kg in croquette, and 18.4 mg/kg in radish.

Simultaneous determination of residues of emamectin and its metabolites, and milbemectin, ivermectin, and abamectin in crops by liquid chromatography with fluorescence detection

A liquid chromatographic (LC) method was developed for the determination of emamectin and its metabolites (8,9-Z-isomer, N-demethylated, N-formylated, and N-methylformylated emamectin) in various crops. The analytes were extracted with acetone, cleaned up on cartridge columns (C18 and NH2), derivatized with trifluoroacetic anhydride and 1-methylimidazole, and determined by LC with fluorescence detection. Because radish inhibited the formation of the fluorescent derivatives, an additional Bond Elut PRS cartridge was used in the cleanup of Japanese radish samples. During sample preparation, N-formylated emamectin partially degraded to emamectin B1b and emamectin B1a, and the 8,9-Z-isomer partially degraded to N-demethylated emamectin. Therefore, emamectin and its metabolites were determined as total emamectin, i.e., their sum was estimated as emamectin benzoate. Their recoveries from most crops were approximately 80-110% with the developed method. The detection limits for the analytes in vegetables were 0.1-0.3 parts per trillion (ppt). The results for these compounds were confirmed by LC/mass spectrometry (LC/MS; electrospray ionization mode). Because the fluorescent derivative of emamectin was undetectable by LC/MS, the results for the analyte were confirmed by using a sample solution without derivatization. Limits of detection by LC/MS were similar to the fluorescence detection limits, 0.1-0.3 ppt in vegetables. In addition to the emamectins, milbemectin, ivermectin, and abamectin were also determined by the developed method.

Eleven phthalate esters and di(2-ethylhexyl) adipate in oneweek duplicate diet samples obtained from hospitals and their estimated daily intake

Plasticizers in duplicate diet samples obtained over 1 week were analysed in order to estimate daily intake. The phthalate esters were as follows: diethyl, dipropyl, dibutyl, dipentyl, dihexyl, butylbenzyl, dicyclohexyl, di(2-ethylhexyl), dioctyl, diisooctyl (mixture of isomers) and diisononyl (mixture). Di(2-ethylhexyl) adipate was also determined. Homogenized samples of composite meals were extracted with acetonitrile, lipids were removed by extraction into n-hexane and the acetonitrile layer was cleaned using Florisil and Bondesil PSA dual layer column. Phthalates were determined by GC/MS (SIM). Phthalate recovery from the fortified food mixture by this method was 62.5-140.8%. Quality assurance as assessed by three laboratories indicated coefficient of variance in the levels of detected phthalates in same lot samples as below 10%. Detection limits were 0.1-23 ng/g for each phthalate. One-week duplicate diet samples provided by three hospitals in three remote prefectures of Japan were analysed as individual meals. In all 63 samples, DEHP was present at the highest level among all phthalates in the range 10-4400 ng/g. The intake of plasticizers estimated from all samples was 519 microg DEHP/day, 86 microg DEHA/day, 65 microg DINP/day, and 4.7 microg BBP/day. Calculated DEHP in 2-day samples out of 21 days exceeded EU TDI for a person of 50 kg body weight (1850 microg per day). Disposable PVC gloves used during the preparation of meals were suspected as the source of the high DEHP content. One-day intake of the other phthalates and DEHA was below 7% of TDI in all cases. High concentrations of DEHP (5990 ng/g) was found in baby food used in quality assurance work. The source of contamination was the PVC-tube used during production and was effectively reduced by replacing the tube by one made of stainless steel.

[Modification of HPLC conditions for the determinations of raw materials, intermediates and subsidiary colors in 5 kinds of food azo colors]

Modification of HPLC conditions for the determinations of raw materials, intermediates and subsidiary colors (organic impurities) in 5 kinds of food azo colors were studied in order to analyze them simply and rapidly. The organic impurities were determined by HPLC using L-column ODS and a gradient system (0.02 mol/L ammonium acetate solution for 10 min, and a gradient with a mixture of acetonitrile and water (7:3)). The organic impurities in 163 samples of azo colors subjected to inspection in fiscal year 1999 were determined under the proposed HPLC conditions. It was found that the contents of organic impurities in 163 samples were less than the limit of Japan's Specifications and Standards for Food Additives, 7th Edition.

[Contents of eleven phthalates and di(2-ethylhexyl) adipate in retail packed lunches after prohibition of DEHP-containing PVC gloves for cooking purposes]

Ten samples of retail packed lunches purchased from convenience stores were determined for 11 phthalates and di(2-ethylhexyl) adipate (DEHA) in August 2000, 2 months after the prohibition of DEHP-containing PVC gloves in Japan. Each homogenized sample was extracted with acetonitrile, partitioned with n-hexane, and cleaned up using Florisil and PSA columns. Phthalates in the extract were determined by GC/MS (SIM). The limits of detection were 14.9 ng/g for di(2-ethylhexyl) phthalate (DEHP) and 18.6 ng/g for dibutyl phthalate (DBP). Levels of phthalates in packed lunch samples were 45 to 517 ng DEHP/g (198 ng/g, average), ND to 90 ng DEHA/g, and ND to 10.0 ng BBP/g. Diisononyl phthalate (DINP) was detected in one sample at 76 ng/g. Average DEHP level in ten samples was 4% of that in 1999. The contents of other phthalates were also reduced. DBP was not detected in any sample. Recovery of deuterated isomers added as surrogates was 27.9% for DNP-d4, and 40.6 to 101.5% for the other phthalates.

[Determination of bisphenol A in foods using GC/MS]

An analytical method using GC/MS was developed for bisphenol A (BPA) in foods and BPA was determined in canned foods and fresh foods such as vegetables, fruit and meat. BPA was extracted with acetone from the samples and the extract was concentrated at under 40 degrees C in vacuo to afford an aqueous solution, which was washed with hexane after alkalization and extracted with 50% diethyl ether-hexane after acidification. Extracts were cleaned up on a PSA and/or a C18 cartridge column, and BPA was derivatized with heptafluorobutyric anhydride and determined by GC/MS (SIM). This method was applicable to the detection and determination of BPA residues in food samples at the level of 1 ng/g. Among canned foods, BPA was found in 6 corned beef, 1 chicken, 9 sweet corn and 3 bean samples at the levels of 17-602 ng/g, 212 ng/g, 2.3-75 ng/g and 3.5-26 ng/g, respectively. BPA was also detected in 1 retort soup and 1 retort pack product at the levels of 11 ng/g and 86 ng/g, respectively. As for dairy products, BPA was not detected in butter and milk. Among fresh foods, BPA was detected in 2 fish and 3 liver samples at the levels of trace (tr)-6.2 ng/g and tr-2.2 ng/g, respectively. In vegetables, fruits and chocolates, a trace level of BPA was detected in only 1 chocolate. Traces of BPA were also detected in 3 samples of 6 boxed lunches.

Influence of jam processing on the radical scavenging activity and phenolic content in berries

Six selected phenolic aglycons (caffeic and ellagic acids, kaempferol, quercetin, myricetin, and morin) in nine types of berries, and their changes as influenced by jam processing, have been evaluated using optimized HPLC with diode-array detection. The berry samples, fresh and after jam processing, were analyzed, and the total amounts of selected phenolics as aglycons were identified and determined by acid hydrolysis. Their contents in fresh and jam samples did not indicate appreciable changes; therefore, the influence of jam processing on these selected phenolics in berries was suggested to be small, and was mostly present in berries as several conjugated forms that were glycosylated, esterified, etc., in the samples. The total phenolic content of each sample was also determined by the Folin-Ciocalteu method. The three samples of each berry, namely fresh, jam, and acid hydrolysate of the berry, had similar total phenolic contents. On the other hand, the scavenging effect on the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical was measured, and acid hydrolysates showed stronger activity than that of the fresh and jam-processed samples for all of the berry types.

Liquid chromatographic determination of emamectin, milbemectin, ivermectin and abamectin in crops and confirmation by liquid chromatography-mass spectrometry

Emamectin, milbemectin, ivermectin and abamectin are similar macrocyclic lactone chemicals used as an acaricides or parasiticides. We developed a simultaneous analytical method for determining the residual amounts of these compounds and emamectin metabolites in crops. A sample extracted with acetone was cleaned up with Bond Elut C18 and NH2. The sample was then fluorescence-derivatized with trifluoroacetic anhydride and 1-methylimidazole in acetonitrile. The analyte was measured by HPLC with fluorescence detection using an octadecylsilyl column with 3 microm particle size and gradient elution. In most crops, their recoveries by the developed method were ca. 80-110%. The detection limits of the analytes in vegetables were 0.1-0.3 ppt. Using the developed method, we surveyed the residues of these compounds in 20 commercial crops in Osaka, Japan. The result of the surveillance was that emamectin benzoate of 0.2-6.7 ppb was detected in nine cases and milbemectin of 16.7-279.3 ppb was detected in four cases. The detected samples were confirmed by LC-electrospray ionization (ESI) MS. The limit of detection by LC-ESI-MS was similar to the fluorescence detection level of 0.1-0.3 ppt in vegetables except for milbemectin.

High-performance liquid chromatographic determination with photodiode array detection of ellagic acid in fresh and processed fruits

A high-performance liquid chromatographic (HPLC) procedure based on an isocratic elution with photodiode array detection has been developed for a simple and rapid determination of ellagic acid (EA) in fresh and processed fruits. The homogenized sample was refluxed with methanol and then the extract was refined using a solid-phase cartridge before HPLC. We analyzed EA in 40 kinds of fresh fruits and 11 kinds of processed fruits by the developed method. EA was found in several berries, fueijoa, pineapple and pomegranate. This is the first occurrence of the detection of EA in bayberry, fueijoa and pineapple.

Determination of phenolic acids in fruit juices by isocratic column liquid chromatography

A simple and rapid analytical method of five phenolic acids, gallic, chlorogenic, caffeic, ellagic and ferulic acid, which are naturally occurring bioactives, were determined in fruit juices by isocratic LC using photodiode array UV detection. The sample was pre-treated by solid-phase extraction (a combination of Sep-Pak Plus tC18 and Bond Elut PSA).

[Estimated production by the official inspection of coal-tar dyes (including dye aluminum lakes) in fiscal year 1998]

There were 284 official inspections of coal-tar and their lakes in fiscal year 1998, and 283 of the lots qualified, one of the 40 samples of Food Yellow No. 5 was rejected. The quality of coal-tar dyes that passed inspection in Japan in fiscal year 1998 reached 150.3 tons. Coal-tar dye production is summarized by manoth in Table 2 and by manufacturer in Table 3. The food coal-tar dye produced in the largest quantity was Food Yellow No. 4, accounting for 44.1% during this period.

[Studies on rejected food yellow No. 5 (sunset yellow FCF)]

One of the sunset yellow FCFs (Y-5) in the official inspection of coal-tar dyes in 1998 was rejected. The results of tests of the rejected sample were submitted to JSFA-VI except for a sub-spot by paper chromatography. HPLC of the raw materials, intermediates, and subsidiary dyes according to JSFA-VII was performed on the rejected and submitted samples of Y-5. The sub-spot in the rejected sample was identified as sulfanilic acid-azo-R salt, and its content was estimated at more than 5%.

Degradation of malathion and phenthoate by glutathione reductase in wheat germ

Residual malathion in wheat was estimated at a lower value when analysis was performed by extraction with acetone after addition of water to swell the wheat, according to the Japanese Bulletin Method. The supernatant of the wheat homogenate showed degradation not only of malathion but also of phenthoate. Malathion and phenthoate were not degraded by the boiled supernatant of the wheat homogenate. It was presumed for this reason that glutathione reductase (GR; EC 1.6. 4.2) in the wheat degraded malathion. The following results were obtained: (1) GR originating in wheat could degrade malathion and phenthoate. (2) The degradation of malathion by the GR was inhibited by excessive GSSG. (3) There was a high correlation between GR activity and malathion degradation activity of the supernatant of wheat homogenates. It is likely that GR acted on the specific structure of malathion and phenthoate, the S=P-S bond, and the blanch structure bonding with the sulfur atom. Following the above, extraction with acetone after addition of water (the Japanese Bulletin Method) should be replaced by extraction with pure organic solvent and without addition of water for swelling.

Determination of the levels of isoflavonoids in soybeans and soy-derived foods and estimation of isoflavonoids in the Japanese daily intake

The levels of 6 kinds of isoflavonoids found in 11 domestic and imported soybeans, and 12 kinds of soybean-based processed foods in Japan were systematically analyzed, and the Japanese daily intake of isoflavonoids from those foods was estimated. The total isoflavonoids (daidzein, glycitein, and genistein) were analyzed with acid hydrolysis and the intact isoflavonoids (daidzein, glycitein, genistein, daidzin, glycitin, and genistin) were analyzed without hydrolysis. This was followed by cleanup with an ODS cartridge column and determined by liquid chromatography with a diode array detector. The highest content of isoflavonoids was found in kinako (a roasted soybean powder) and the lowest was found in soy sauce. The contents and composition of the isoflavonoids in the 11 soybeans varied by species and country of origin. The level of isoflavonoids found in the processed foods varied by manufacturing method or ingredients. The percentage of aglycone tended to be higher in miso (fermented soybean paste) and soy sauce, which are heated and fermented during the manufacturing process. Japanese daily intake of isoflavonoids from soybeans and soybean-based processed foods was estimated as 27.80 mg per day (daidzein 12.02 mg, glycitein 2.30 mg, and genistein 13.48 mg).

Fecal steroid excretion is increased in rats by oral administration of gymnemic acids contained in Gymnema sylvestre leaves

Gymnemic acids are the saponins with a triterpenoid structure contained in Gymnema sylvestre leaves and have the hypoglycemic effects. In spite of the cholesterol-binding properties of saponins, the effect of gymnemic acids on cholesterol metabolism has not been elucidated to date. We investigated the effects of gymnemic acids on fecal steroid excretion in rats. Three kinds of extracts from Gymnema sylvestre leaves, extract (GSE), acid precipitate (GSA) and column fractionate (GSF), of which the gymnemagenin (an aglycone of gymnemic acids) concentrations are 58.87, 161.6, and 363.3 mg/g respectively, were used for the experiments. These were administered to rats orally at the dose of 0.05-1.0 g/kg for 22 d. Rats were given free access to water and nonpurified diet without cholesterol, and the differences in fecal excretion of steroids and gymnemic acids were investigated. Although there were no significant effects of GSE, GSA and GSF decreased body weight gain and food intakes in a dose-dependent manner (P < 0.01). GSF (1.0 g/kg) significantly increased fecal excretion of neutral steroids and bile acids in a dose-dependent manner (P < 0.05), especially those of cholesterol and cholic acid (CA)-derived bile acids. The increases in fecal steroid excretion of cholesterol, total neutral steroids, total bile acids and CA-related bile acids were acute and significantly correlated with fecal gymnemagenin levels (r2 = 0.2316-0.9861, P < 0. 05). These results demonstrated for the first time that a high dose of gymnemic acids increases fecal cholesterol and CA-derived bile acid excretion. Further studies are needed to clarify the effect of gymnemic acids on cholesterol metabolism.

[Estimated production by the official inspection of coal-tar dyes (including dye aluminum lakes) in 1997]

The number of official inspection of coal-tar dyes and their lakes from April in 1997 till March in 1998 were 571 in total. The quantity which passed inspection amounted to 160.3 ton in Japan. The production of color in each month was summarised in Table 1, and by each producing company in Table 2. The food coal-tar dye produced in the largest quantity was Food Yellow No.4, occupying 39.8% in this period.

[Determination of tocopherols in oils of mixed tocopherol as food additive using reverse-phase high-performance liquid chromatography]

Simultaneous determination of four tocopherols was developed using reverse-phase high-performance chromatography with a mixture of methanol and water (88:12) as a mobile phase. The alpha-, beta-, gamma- and delta-tocopherols in oils of mixed tocopherol as food additive were determined. It is clarified that the proposed method is useful for the quality control of food additive.

[Simultaneous analysis and detection of pesticides in fresh fruits and vegetables by HPLC and GC]

A method was established for simultaneous determination of pesticide residue in fresh fruits and vegetables by HPLC and GC. CH3CN extraction/NaCl partiton method was used in order to recover hydrophilic pesticide such as acephate, methamidophos. Dimethoate and methamidophos from okra and DDVP from strawberry were detected by GC. On the other hand confirmation method by GC and GC/MS was studied for peaks detected by HPLC with UV and/or FL detector. OPP, TBZ, imazalil chlorpyrifos etc. in citrus fruits were detected by the proposed method.

Differences in behavior among the chlorides of seven rare earth elements administered intravenously to rats

Differences in behavior among the chlorides of seven rare earth elements (REEs)-yttrium (Y), cerium (Ce), and praseodymium (Pr) (light REEs); europium (Eu) and dysprosium (Dy) (medium REEs); ytterbium (Yb) and lutetium (Lu) (heavy REEs)-were investigated through intravenous administration of the REEs to rats. (1) Distributions of REEs and mineral concentrations in the organs on Day 1 were investigated at low and high doses (9-10 and 18-20 mg REE/kg, or 56-66 and 112-132 mumol REE/kg). More than 78% of the REEs administered was distributed into liver, bone, and spleen. High doses of Y, Eu, and Dy markedly increased the accumulation of REEs in spleen and lungs as well as the concentration of Ca in liver, spleen, and lungs. (2) The distribution patterns of REEs and changes in Ca concentrations in major organs over time were investigated by the administration of Pr, Eu, Dy, Yb (low dose), and Y (high dose). REEs disappeared from the blood within 1 day but were retained in the organs for a long time. The percentages of the doses of Y, Eu, Dy, and Yb found in the liver were highest at 8 hr to 2 days, then decreased gradually; hepatic Pr levels, however, remained high. Changes in Ca concentrations in liver, spleen, and lungs were in accordance with those of REEs. (3) Severe hepatotoxicity was observed after administration of Ce and Pr; fatty liver, jaundice, and elevated serum GOT and GPT levels were most prominent on Day 3. Therefore, we hypothesized that REE chlorides might be categorized into three groups according to their ionic radii (light REEs, Y and medium REEs, and heavy REEs) and from their behavior, i.e., distribution pattern, Ca-accumulating action, and hepatotoxicity.

Potential interference by free fatty acids in determination of tricyclazole in brown rice by gas chromatography with flame thermionic detection

A convenient method is described for the determination of tricyclazole in brown rice, and the interference of free fatty acids with flame thermionic detection (FTD) is reported for the first time. Brown rice is extracted with acetone, the extract is filtered, and the filtrate is evaporated. To the residue is added 10% (w/v) NaCl solution, and the mixture is extracted with ethyl acetate. The extract is charged on a Sep-Pak Plus silica cartridge. Free fatty acids are removed from the rice by washing with diethyl ether, and tricyclazole is eluted with acetone-n-hexane (1 + 1). Tricyclazole is determined on a DB-1 capillary column by gas chromatography with FTD (GC-FTD). Linoleic acid and oleic acid, which have essentially the same retention time as tricyclazole, cannot be detected by FTD. Thus, without the Sep-Pak Plus silica cleanup, the peak height of tricyclazole in the chromatogram decreased, the extent depending on the concentration of linoleic acid. n-Hexane-acetonitrile partitioning was not used for cleanup because it could not remove 50% of the free fatty acids. Recoveries (mean +/- standard deviation, n = 5) of tricyclazole from rice fortified at 2 and 0.1 ppm were 90.5 +/- 9.4% and 81.3 +/- 10.6%, respectively. The limit of quantitation was 0.05 ppm.

Determination of pyrethroid residues in vegetables, fruits, grains, beans, and green tea leaves: applications to pyrethroid residue monitoring studies

Determination of natural pyrethrins and 12 synthetic pyrethroids in agricultural products was investigated. Vegetables and fruits were extracted with acetone, filtered after addition of coagulating solution, partitioned into n-hexane, and cleaned up on a Florisil column (as necessary). Pyrethroids were determined by gas chromatography/electron capture detection (GC/ECD) by using a methyl silicone-coated fused-silica capillary column, and recoveries were calculated by summing peak areas of the components. GC/mass spectrometry was used to identify the pyrethroids detected by GC/ECD monitoring. Grains and beans containing lipids were analyzed by extraction with acetonitrile, partition into n-hexane, Florisil column cleanup, and capillary GC/ECD. The coagulation method was suitable for nonfatty crops such as vegetables, fruits, and green tea leaves, because recoveries were good and Florisil column cleanup was not needed in most cases. The coagulation method was not applicable to lipid-containing crops such as grains and beans because of low recoveries. Recoveries for 18 crops at fortification levels of 0.25-1.0 ppm were 60.0-103.5%. No pyrethroids were detected from the nonfortified crops tested except green tea leaves, in which fluvalinate was detected at 0.89 ppm.

[Studies on the identification of sulfadimidine in pork by high performance liquid chromatography with photodiode array detector and gas chromatograph-mass spectrometry]

Sulfadimidine (SDD) was detected in pork imported from Mexico by HPLC with gradient elution system. UV spectrum of the peak was measured and confirmed by photodiode array detector, moreover identified by GC/MS after methylation with diazomethane. Content of SDD in the sample was 0.1 ppm and detection limit of SDD by the proposed method was 0.02 ppm. Application of this method to CLP, SMR, SMM, SDM and SQX was studied, and satisfactory results were obtained.

[Studies on the analysis of copper chlorophyll and sodium copper chlorophyllin in imported foods]

The analysis of copper chlorophyll (CuCh) and sodium copper chlorophyllin (CuCh-Na) in imported foods was carried out. Standards of CuCh and CuCh-Na were examined by ultraviolet and visible spectrophotometer. CuCh gave absorption maximum around 650 nm, while CuCh-Na gave around 630 nm. Imported sweets and liqueurs were homogenized and extracted with ethyl acetate. These extracts also gave absorption maxima absorbance around 650 nm or 630 nm. The results suggested that a distinction between CuCh and CuCh-Na in foods was possible by spectrophotometry. Visible spectrophotometric quantitation was also tried. However the estimated levels of CuCh or CuCh-Na in the samples by this method did not meet with those by atomic absorption spectrometry.

Determination of organophosphorus pesticides in imported foods by FPD-GC and GC-MS

Organophosphorus pesticides in 47 agricultural products imported at the Yokohama and Kobe Quarantine Station in 1990 were determined by FPD-GC and identified by GC-MS. Chlorpyrifosmethyl, malathion and fenitrothion were found in wheat (0.03-0.69 ppm), chlorpyrifosmethyl and fenitrothion in soy bean (0.02-1.03 ppm), chlorpyrifosmethyl in cherry (0.12-0.17 ppm), chlorpyrifosmethyl in pumpkin (0.07-0.15 ppm), chlorpyrifosmethyl and malathion in corn (0.15-1.38 ppm).

[Analytical results of post-harvest pesticides in citrus fruits and fruits juices by GC-MS (SIM) and HPLC with fluorescent detector]

Determination of 6 kinds of post-harvest pesticides (DP, OPP, TBZ, 2,4-D, Imazalil and Benomyl) in citrus fruits and fruits juices was carried out by GC-MS (SIM) and HPLC with fluorescent detector. DP for 16 samples, OPP for 27 samples, TBZ for 12 samples, 2,4-D for 10 samples, imazalil for 20 samples and Benomyl for 4 samples were detected in total 32 samples.

Quantitation of 13-hydroxyoctadecadienoic acid (13-HODE) by radioimmunoassay

Antibodies against 13-hydroxyoctadecadienoic acid (13-HODE) were produced in rabbits by immunizing the animal with 13-HODE-thyroglobulin conjugate. The antibodies appeared to be rather specific for 13-HODE since other hydroxy fatty acids showed minimal crossreaction. The radioimmunoassay was capable of detecting 50 pg per assay tube and was applied to the study of the biosynthesis of 13-HODE in platelets and leukocytes. In contrast to reported findings from endothelial cells, A-23187, thrombin and collagen stimulated synthesis and release of 13-HODE from platelets. However, insignificant synthesis of 13-HODE was found in leukocytes following A-23187 stimulation. Exogenous addition of linoleic acid stimulated the synthesis of 13-HODE from both platelets and leukocytes. The majority of 13-HODE synthesized was found in the medium. These studies suggest that both types of blood cells possess active (omega-6) lipoxygenase. Platelets may use endogenously released linoleic acid to synthesize 13-HODE, whereas leukocytes may utilize linoleic acid released from other cell types for 13-HODE synthesis.

Actual survey on TLm (median tolerance limit) values of environmental pollutants, especially on amines, nitriles, aromatic nitrogen compounds and artificial dyes

Forty-four kinds of organic nitrogen compounds as well as 37 kinds of dyes which contained nitrogen were subjected to TLm test by use of Himedaka (Oryzias latipes) and the results were compared with their partition coefficients between n-octanol and water. Concerning organic nitrogen compounds, such good correlation was observed among them that the larger the partition coefficient was, the smaller was the TLm value. Their acute toxicity to fish was supposed to be revealed after their passage through cell membrane of fish to be accumulated in the body. As far as coal-tar dyes and dyestuffs were concerned, there was a correlation between partition coefficient and TLm value. Methylene blue and rose bengale showed strong acute toxicity to fish and it was assumed that high affinity of these dyes to gill was responsible to depressing the function of gill, to make fish suffer from anoxemia and die.

Improved 4-aminoantipyrine colorimetry for detection of residual hydrogen peroxide in noodles, fish paste, dried fish, and herring roe

Improved 4-aminoantipyrine (4-AA) colorimetry was developed for the detection of minute quantities of residual hydrogen peroxide in several kinds of food. Hydrogen peroxide in the sample was stabilized with potassium bromate and extracted with cold methanol. The methanol extract was diluted with phosphate buffer, protein was eliminated with zinc sulfate, and the extract was reacted with phenol, 4-AA, and peroxidase to the stable quinoneimine dye. The weak color solution was purified with Florisil column chromatography, concentrated, and determined by colorimetry. Recoveries of hydrogen peroxide from samples fortified at 0.5, 2, and 10 ppm ranged from 70.7 +/- 8.9 to 98. 5 +/- 1.2%. Color development was linear with amount of H2O2 from 0.5 to 20 micrograms, corresponding to 0.05-2 ppm in samples.

Gas-liquid chromatographic detection an determination of diacetyl tartaric acid ester of diglyceride in dairy and nondairy coffee cream powders

Diacetyl tartaric acid ester of diglyceride was directly extracted from dairy or nondairy coffee cream powder under acidic conditions with ethyl acetate; then the extract was saponified with methanolic potash. After acidification with HCl, free fatty acid was removed with ether and the reaction mixture was absorbed on an anion exchange column. Tartaric acid was eluted with 2N HCl-acetone (1+1). An aliquot of the trimethylsilyl (TMS) derivative of the eluate was injected into a gas chromatograph with flame ionization detection, and a 1.5% SE-30 column. Recoveries of diacetyl tartaric acid ester of diglyceride at 50, 200, and 2000 ppm were 85.6-99.5%.

Gas-liquid chromatographic determination of tertiary-butylhydroquinone (TBHQ) in dried fish, frozen shrimp, vegetable oils, butter, and margarine

Tertiary-butylhydroquinone (TBHQ) is extracted from foods with ethyl acetate, the solvent is evaporated, the residue is dissolved in n-hexane-ethyl acetate (99 + 1), and the TBHQ is selectively transferred into an aqueous layer (2% sodium chloride) as a separation from food interferences. Finally, TBHQ is reextracted with n-hexane-ethyl acetate (1 + 1), concentrated, and determined by flame ionization gas-liquid chrmoatography. Dried fish, frozen shrimp, vegetable oils, and edible fats were analyzed by the method. More than 85% was recovered when the samples were fortified with 100 ppm TBHQ. Detection limit was 1.0 ppm TBHQ.

Studies on the toxicity of coal-tar dyes. III. Reason of acute toxicity to fish caused by coal-tar dyes and their industrial effluents

Reason of acute toxicity to fish caused by coal-tar dyes and their industrial effluents were studied from the three points of view. 1) Partition coefficient (n-octanol/water) was determined on several coal-tar dyes, and it was found that the larger the ratio was, the stronger was toxicity to fish. 2) As a result of determination about existent form of xanthene dyes under photo-irradiation, it was clarified that dyes in solution were in the form of excited triplet state and halogen in dye molecule was liberated in free form. 3) When coal-tar dyes were treated with sodium hypochlorite, harmful chloroform was detected from dye solution. Chloroform and its homologous compounds showed the low TLm value and had the serious effect on fish.

Studies on the toxicity of coal-tar dyes II. Examination of the biological reaction of coal-tar dyes to vital body

The toxicity of xanthene dyes were studied by various interaction between the dyes and the components in vital body. (1) An increase in the amount of Rose Bengale adsorbed on the gill of fish was followed by the increase in red corpuscle number, and it was assumed that the death of fish in xanthene dye solution was due to anoxemia. (2) Binding capacity of xanthene dyes with bovine serum albumin decreased in the following; Rose Bengale, Phloxine, Erythrosine, Eosine and Uranine. This order was quite coincident with the toxicity compared by TLm values. (3) From the results of rec-assay test by use of Bacillus subtilis, it was confirmed that Phloxine and Rose Bengale had DNA-damaging capacity related to the mutagenecity.

Studies on the toxicity of coal-tar dyes. I. Photodecomposed products of four xanthene dyes and their acute toxicity to fish

The acute toxicity of photodecomposed products of Erythrosine, Eosine, Phloxine and Rose Bengale were studied, since it was found that toxicity of these dyes to fish increased after the dyes had been photoirradiated. Photodecomposed products of the dyes were isolated and identified with UV, IR, NMR spectra and the acute toxicity of those compounds were determined by TLm test. As results of these studies, it became clear that the toxicity of photodecomposed organic products (dehalogenated compounds of dyes) were lower than the mother compounds. The increases in toxicity of the xanthene dyes by photo-irradiation were attributed to the liberated halogens by irradiation.

Biochemical decomposition of coal-tar dyes. I. Biochemical decomposition and identification of decomposed products

Biochemical degradation test of food coal-tar dyes using sludge was studied in order to evaluate their safety. It was found that some dyes were little decomposed under aerobic condition but four azo dyes were readily decomposed under anaerobic condition. These were Food Yellow No. 4, No. 5, and Food Red No. 2, No. 102. Decomposed products of these four azo dyes by sludge under anaerobic condition were identified as sulfonilic, naphthionic acids and so on.

Biochemical decomposition of coal-tar dyes. II. Acute toxicity of coal-tar dyes and their decomposed products

Twenty kinds of coal-tar dyes were subjected to median tolerance limit (TLm) test by use of Himedaka (Oryzias latipes) for the comparision of their acute toxicities. It became clear that 4 kinds of halogens substituted xanthene compounds dyes showed strong acute toxicities. From the fact that uranine had the lower acute toxicity than halogens substituted compounds and the toxicities of these 4 dyes increased through irradiation, it was assumed that halogen atoms in dyes might be responsible for these strong acute toxicities to fish.