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Biomedical subjects

H Shintani

Publications and source records attributed to H Shintani.

At least 109 records · Page 6Linked to original sources
PubMed1986

Simultaneous determination of serum uremic toxins, cations and anions and urea determination by post-column colorimetry using immobilized enzyme.

A column-switching method which combines ion-exchange and ion-pair reversed-phase chromatography was developed for the determination of serum uremic toxins, cations and anions. Serum urea, which was poorly separated by reversed-phase chromatography, was analyzed using an immobilized-urease column and detected by post-column colorimetry. Apart from the simultaneous analysis, anion analysis using ion-pair reversed-phase chromatography on an ODS column was also developed. The origin of the system peak observed in anion analysis with an eluent containing phthalate has been clarified.

Chromatography, Ion Exchange↗
PubMed1985

Simultaneous determination of serum cations, anions and uremic toxins by ion chromatography using an immobilized enzyme.

A procedure is described for the analysis of serum cations and uremic toxins by simultaneous conductivity (CD) and ultraviolet (UV) photometric detection and using phosphoric acid as the eluent. In addition, studies were made on the determination of urea in serum using immobilized urease, and on the simultaneous determination of cationic and anionic compounds. The ammonium ion produced from urea by immobilized urease was determined by CD. No significant differences in amounts were found between the present method and conventional colorimetric methods. There was no significant reduction in immobilized urease activity after two months of continuous use. Simultaneous analysis of cationic and anionic compounds in serum was performed by switching valves in order to change the eluents and to change the channel to the analytical column. No marked base-line variation was observed and satisfactory recovery of anions was achieved.

Ammonia↗
PubMed1985

Improvement of ion chromatography with ultraviolet photometric detection and comparison with conductivity detection for the determination of serum cations.

Studies were made of the analytical conditions required for indirect photometric ion chromatography using ultraviolet photometric detection (UV method) for the determination of serum cations following a previously developed serum pre-treatment. The sensitivities of the conductivity detection (CD) and UV methods and the amounts of serum cations determined by both methods were compared. Attempts to improve the sensitivity of the conventional UV method are reported. It was found that the mobile phase previously reported by Small and Miller showed no quantitative response when more than 4 mM copper(II) sulphate pentahydrate was used. As a result, there was no significant difference in the amounts of serum cations shown by the CD and UV methods. However, by adding 0.5-5 mM cobalt(II) sulphate heptahydrate, nickel(II) sulphate hexahydrate, zinc(II) sulphate heptahydrate or cobalt(II) diammonium sulphate hexahydrate to 0.5-1.5 mM copper(II) sulphate pentahydrate, higher sensitivity and a quantitative response were attained.

Calcium↗
PubMed1985

Determination of phthalic acid, mono-(2-ethylhexyl) phthalate and di-(2-ethylhexyl) phthalate in human plasma and in blood products.

Pretreatment for the determination of phthalic acid, mono-(2-ethylhexyl) phthalate (MEHP) and di-(2-ethylhexyl) phthalate (DEHP) in human serum or plasma, and the determination of these compounds in blood products by high-performance liquid chromatography was studied. The amount of phthalic acid, MEHP and DEHP, migrated into blood products from a flexible bag, was studied. About 0.1% of DEHP in a flexible bag was found to have migrated into human platelet plasma. Most of the MEHP and phthalic acid detected in human platelet plasma was not derived from the flexible bag but was produced by enzymatic hydrolysis of the migrated DEHP. The amount of DEHP eluted into blood products from the flexible bag differed, depending upon storage time, storage temperature, etc.

Acetonitriles↗