※一部利用できない機能があります
| 1.
論文 |
論文
|
山本, 敦 ; 松永, 明信 ; 関口, 久義 ; 早川, 和一 ; 宮崎, 元一
概要:
Photometric ion chromatography is a novel method by using the photometer as a detector. A feature of this method is the use of light absorbing ion in the mobil phase, and the appearance of transparent sample ion in the effluent is
…
detected by "trough"in the base line absorbance. We applied this technique by using a conventional HPLC system equipped with a commercially available ion exchange separation column to the determination of bromate in such foodstuffs as bread and kamaboko. Sample solution was prepared by aqueous extraction and mixed with acetone for removal of proteins. After evaporation of the organic solvent, the aqueous solution was dechlorinated by a DOWEX column (Ag-form), and then was subjected to chromatography. Samples of bread and kamaboko were spiked with 5.4 ppm and 8.4 ppm of bromate, respectively, and examined by the above method. The average recoveries were 88.3% in bread and 82.9% in kamaboko, and the coefficients of variation were 7.7% and 7.9%, respectively. The detection limit was 1 ppm. The above findings indicate that bromate can be detected by HPLC using conventional instrumentation, and the sensitivity of this system is comparable to conductimetric detection.
続きを見る
|
||||
| 2.
論文 |
論文
|
松永, 明信 ; 山本, 敦 ; 水上, 英一 ; 早川, 和一 ; 宮崎, 元一
概要:
A high-performance liquid chromatographic method using post column reaction system was established for the determination
…
of polyphosphates (PP). Linear polyphosphates with the range of polymerization from 2 to 9 (P2-P9) could be separated on an anion exchange column, TSK GEL DEAE-5PW (Toyo Soda), with 0.01 M HNO3 containing NaNO3 as a mobile phase at flow rate of 1.0 ml/min, with a linear gradient in NaNO3 concentration at one hour intervals. PP were detected as the decrease of absorbance at 500 nm of ferric-sulfosalicylate complex by means of an on-line post column reaction at room temperature, with 0.5 mM FeCl3 containing 2.5 mM sulfosalicylic acid as reaction reagent at flow rate of 0.5 ml/min. The proposed method was applied to the analysis of 30 different commercial products of soft drinks. The pretreatment only necessary after mixing the sample with an equal volume of 0.01 M HNO3 was filtration through 0.45 μm pore size filter. P2-P6 (total 0.231 g/kg) and P2-P4 (0.070 g/kg) were found from 2 kinds of the samples, respectively. The determination limit was 0.02 m mol/kg for all of the PP.
続きを見る
|
||||
| 3.
論文 |
論文
|
山本, 敦 ; 松永, 明信 ; 牧野, 正雄 ; 早川, 和一 ; 宮崎, 元一
概要:
A method for the simultaneous determination of organic acids was investigated by photometric ion chromatography by using
…
two different eluents. A 4.6 mm i.d.×25 cm stainless column packed with MCI GEL SCA 01 (Mitsubishi Chemical Ind., Ltd.) was used as a separator column. Sample was injected into this column previously equilibrated with 1 mM citraconic acid at pH 6.8. After elution of monobasic organic acids, the eluent was exchanged to a stronger one, 1 mM m-sulfobenzoic acid at pH 6.8. Dibasic organic acids were eluted before the column reequilibration with the secondary eluent. On the other hand, tribasic organic acids such as citric acid were eluted with the secondary eluent. To prevent the base line disorder due to the eluent exchange, the determination at 254 nm was performed. Because this wave length is an isosbestic point of the two eluents. Sour-taste agents in soft drinks could be analysed directly after dilution of samples.
続きを見る
|
