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Volume 16, Issue 3
Displaying 1-8 of 8 articles from this issue
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Motonobu YOKOSEKI1975 Volume 16 Issue 3 Pages 145-152
Published: June 05, 1975
Released on J-STAGE: December 11, 2009
JOURNAL FREE ACCESSDownload PDF (1060K) -
Analytical Applications of the Dephosphorylation of 5′-Ribonucleotides with Thorium Ion Part 1. A Simple Preparation of RibonucleosidesSadao KUSUI, Akira MURAKOSHI, Taisuke MORITA, Hideyuki MORI1975 Volume 16 Issue 3 Pages 153-159_1
Published: June 05, 1975
Released on J-STAGE: December 11, 2009
JOURNAL FREE ACCESSA simple preparation of ribonucleoside (I) from 5′-ribonucleotide (II) was investigated by taking advantage of the dephosphorylation of II with thorium ion (Th (IV)).
The decomposition of II to I with Th (IV) was remarkably influenced by a kind of buffer solutions employed. The decomposition was greatly accelerated in acetate (pH 3 and 4), Tris-hydrochloric acid (pH 7), and ammonium (pH 9-12) buffers, but completely inhibited in citrate (pH 4), phosphate (pH 7), and carbonate (pH 11) buffers.
An increased reaction temperature in the range of 25 to 100°C tested was advantageous for the production of I from II.
The production of I apparently attained equilibrium when Th (IV) was used 4 times the molar quantity of II in acidic media, and 6-8 times that of II in neutral and alkaline media.
From the results described above, the most suitable conditions for the decomposition of II to I have been established. For the preparation of a purine I, the corresponding II is treated in ammonium buffer (pH 10) with Th (IV) at 8 times the molar quantity of II at 100°C for 2 hours. For that of a pyrimidine I, the corresponding II is decomposed in acetate buffer (pH 3) with Th (IV) at 4 times the molar quantity of II at 100°C for an hour.
All the reaction mixtures treated under the conditions described above were found to be utilized as standards of I, which are examined in the thin-layer chromatography of II described in “The Japanese Standards of Food Additives 3rd Ed”.
It has been suggested that I obtained from II can be simply isolated by suitable separation procedures.View full abstractDownload PDF (729K) -
Analytical Applications of the Dephosphorylation of 5′-Ribonucleotides with Thorium Ion Part 2. A Simplified Determination of 5′-Ribonucleotides in their PreparationsSadao KUSUI, Akira MURAKOSHI, Taisuke MORITA, Hideyuki MORI1975 Volume 16 Issue 3 Pages 160-164_1
Published: June 05, 1975
Released on J-STAGE: December 11, 2009
JOURNAL FREE ACCESSA simplified procedure for the determination of 5′-ribonucleotide (5′-RNT) in seasoning preparations was developed by employing the dephosphorylation of 5′-RNT with thorium ion (Th (IV)).
In the assay, 5′-RNT was catalytically dephosphorylated at pH 3 at 100°C for 120min with Th (IV) in large excess, and then determined colorimetrically on the basis of the well-known interaction between molybdate and phosphoric acid which was liberated from 5′-RNT. Before the dephosphorylation, monosodium glutamate, an inhibitor of dephosphorylation, in the preparations was removed by precipitation at its isoelectric point (pH 3.2), and the colored substances, an interfering factor in the assay of phosphate, in some preparations were also eliminated by passing through an activated charcoal column.
The present method was shown to be useful for the determination of 5′-RNT in the preparations, compared with conventional enzymatic and colorimetric methods using several commercial seasoning preparations.View full abstractDownload PDF (671K) -
Analysis of Chlorinated Pesticides in MilkHiroshi MATSUMOTO, Hisao OKA, Norihisa KAWAMURA, Tadahiro NARAFU1975 Volume 16 Issue 3 Pages 165-171_1
Published: June 05, 1975
Released on J-STAGE: December 11, 2009
JOURNAL FREE ACCESSA new method “Continuous Distillation with Water” for the detection of chlorinated pesticides in milk using a new apparatus (Fig. 1) has been developed. The new aparatus had three improvements: first, an extraction part (A) was narrowed to obtain high extraction efficiency; second, a small jacket was fixed around (A) to be able to be used for low boiling point solvents; third, a liquid-liquid extraction part (B) was fixed to be able to be used for a heavier solvents than water. This operation was as follows: a certain quantities of milk was weighed in a boiling flask then 100ml of water and one drop of phosphoric acid were added, in (A) a small amount of water and 4ml of n-heptane were added; a Liebig condenser was connected and the flask was boiled for 2 hours. After distillation, the lower layer of the (A) was drained off. The n-heptane extract was collected in a small test tube, dried with anhydrous sodium sulfate and used for gaschromatographic analysis.
By this method, the high recovery of chlorinated pesticides from water was obtained. The advantageous points of this method were easy operation in a short time and low cost, although a few pesticides in milk such as β-BHC and p, p′-DDT were less detected. Thus we can conclude that the new distillation method will be able to be used as a supplementary method for the analyses of chlorinated pesticide residues.View full abstractDownload PDF (901K) -
Distribution and Fate of Cadmium in Rat after Repeated Oral Administration and its TerminationGoro URAKUBO, Yoshihito OMORI, Akira TAKANAKA, Kin-ichi ONODA, Akira H ...1975 Volume 16 Issue 3 Pages 172-177_1
Published: June 05, 1975
Released on J-STAGE: December 11, 2009
JOURNAL FREE ACCESSRadioactive cadmium solution was given orally and repeatedly to the following 3 groups of rats (115mCd 2μCi/mg/2ml/kg/day), and the rats were dissected in order to investigate the fate of the metal;
Group (A): given the solution for 30 days, dissected at 31st day,
Group (B): given for 70 days, dissected at 71st day,
Group (C): given for 30 days, then kept for 40 days, dissected at 71st day.
The whole body retention of cadmium was increased roughly along a straight line by daily dosing, however, after 40th day the rate of increase was somewhat declined (Group A, B). On the observation after the termination of dosings for 30 days (Group C), fall of whole body count was outstanding in 2 days, but thereafter, the count was decreased very slowly and the calculated biological half life of absorbed cadmium was 250 days.
During the daily repeated dosings, radioactive cadmium was excreted constantly every day, namely, about 50% of dose to feces and a little amount to urine. After the termination of dosing (Group C), the excretion rate to feces declined in 2 days to the same level as urine.
In all groups of animals, remarkable change of organ weight was not detected. Concerning the accumulation of cadmium, higher concentration in each organ was observed in Group (B) comparing with Group (A). The highest concentration in liver and the secondly highest one in kidneys were noted in Group (A), but in Group (B) almost equally higher accumulation was seen in liver and kidneys. At 41st day after the termination of dosings (Group C), a significant decrease of retention in liver was observed.
As the conclusion, cadmium was absorbed and distributed in liver, kidneys, spleen and other organs, and retained for long period, though the absorption rate of this metal was not so remarkable.View full abstractDownload PDF (755K) -
3, 4-Benzopyrene in Fish and ShellfishYoshiko SHIRAISHI, Tsuyako SHIROTORI, Eigo TAKABATAKE1975 Volume 16 Issue 3 Pages 178-181_1
Published: June 05, 1975
Released on J-STAGE: December 11, 2009
JOURNAL FREE ACCESSAn analytical method was investigated for 3, 4-benzopyrene in fish and shellfish being consumed usually in our daily foods. It was found that the unknown substances extracted from the samples containing high amount of fat interfered the fluorescence of benzopyrene in the final fraction. In order to avoid this obstruction, the clean up step of chromatography on a silica gel column (1×30cm) with petroleum ether: ether (9:1) was added to the method for vegetables previously published. The determination of 3, 4-benzopyrene in the samples by the presented method was possible without any trouble.
The recovery of 3, 4-benzopyrene added to 100g of mackerel at a level of 2ppb was 45.6% by the former method in which silica gel chromatography was not operated, but 91.0% by the improved method. No interference on the fluorescence of 3, 4-benzopyrene was exerted by stearic acid, palmitic acid, behenic acid, lauric acid, myristic acid, cholesterol, or lecithin.
The analysis by the improved method for commercially available fish and shellfish showed no 3, 4-benzopyrene in 11 out of 19 samples but the concentration between 0.08 and 9.85ppb in other samples.View full abstractDownload PDF (482K) -
Youji HOSHINO, Toshimasa SUZUKI, Yoshinori KIKUCHI, Norihide NOSE, Aki ...1975 Volume 16 Issue 3 Pages 182-186_1
Published: June 05, 1975
Released on J-STAGE: December 11, 2009
JOURNAL FREE ACCESSA method of the quantitative determination of saccharin in foods by gas liquid chromatography (GLC) was described.
Saccharin was methylated with dimethylformamide dimethylacetal (DMF-Me) heating for 30min in glycerin bath at 110±5°C. After reaction with DMF-Me, methyl derivative of saccharin obtained was determined by GLC equipped with a flame ionization detector (FID) and an electron capture detector (ECD). GLC was performed using DC-200 (10%) on gas chrom Q as the column and β-BHC as an internal standard.
The recoveries of sodium saccharin added in various foods by the present method were 88.1-94.7%, and the limit of detection as saccharin was about 0.02μg with FID-GLC and 0.02ng with ECD-GLC.
Furthermore, the determination with ECD-GLC was an effective method for the ultramicro-analysis.View full abstractDownload PDF (566K) -
3, 4-Benzopyrene in FruitsYoshiko SHIRAISHI, Tsuyako SHIROTORI, Eigo TAKABATAKE1975 Volume 16 Issue 3 Pages 187-188_1
Published: June 05, 1975
Released on J-STAGE: December 11, 2009
JOURNAL FREE ACCESS3, 4-Benzopyrene was determined on 9 kinds of fruits according to the already reported method. Among the fruits tested, which included apple, banana, pineapple and mandarin orange, very small 3, 4-benzopyrene was detected in eight kinds, with a mean content of 0.03ppb.
With mandarin oranges and bananas, 3, 4-benzopyrene was detected not only in the edible portion but also in the peel.View full abstractDownload PDF (174K)
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