摘要:

Essential aminoacids, vegetables, milk products, seafood, and canned meat were analyzed by the Kjeldahl method to determine their organic nitrogen content. The samples were brought into solution in two different ways, by conventional and by microwave wet acid digestion.

ISSN:0003-2719    

DOI:10.1080/00032718808066330

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

Numerous reports have shown a high degree of correlation between the presence of estrogen and progesterone receptors in cancerous breast tumors and response to endocrine therapy. There are several methods in use for measurement of these receptors, but all are time consuming and require large amounts of tumor tissue. Our laboratory needed a faster and simpler method to determine receptor concentration. We describe here an assay which utilizes human uterus extract with known receptor concentration as a standard to determine receptor concentration of tumor tissues. This method is simple, fast and will allow determination of estrogen and progesterone receptor in up to ten patient samples at one time.

ISSN:0003-2719    

DOI:10.1080/00032718808066331

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

An anti-insulin antibody IgG-coated polystyrene ball of 3.2 mm in diameter was incubated with insulin or sample in a total volume of 50 μl in a small glass tube (3.5 × 20 mm) and subsequently with affinity-purified (anti-insulin) Fab'-peroxidase conjugate in a 50 μl in the same size glass tube. The peroxidase activity bound to the ball was assayed by using fluorimetry, in which the terminal volume for fluorimetric measurement was reduced to 0.5 ml. As a result, detection limit of insulin was as low as 0.3 nU (12.5 fg)/tube. Human insulin in normal saliva was determined by using this highly sensitive sandwich enzyme immunoassay. Gel filtration of concentrated human saliva sample showed that the major peak with insulin immunoreactivity eluted at the same position as monocompone porcine insulin. The level of insulin in normal human saliva was 2.8 + 2.47 (SD) μ/ml (n=8), and a response of saliva insulin secretion by glucose loading was evidenced.

ISSN:0003-2719    

DOI:10.1080/00032718808066332

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

An HPLC method for the determination of salicylic acid (SA), gentisic acid (GA), salicyluric acid (SU), and salicyl acyl glucuronide (SAG) in rat urine was developed. The method consisted of extracting SA, GA, and SU from acidified urine into 50:50 mixture of ethyl acetate and butyl chloride. Salicyl acyl glucuronide was extracted from neutral urine after conversion to salicyl hydroxamic acid with hydroxylamine. Salicyl phenolic glucuronide was estimated indirectly as the difference between total salicylate and sum of the four constituents mentioned above. Chromatographic separation was done on a C18column with U.V. detection at 310 nm using a mobile phase consisting of 5–10% acetonitrile in 3% glacial acetic acid. The extraction recovery of these compounds from spiked urine ranged from 90–108%. The detection limits were 10 μg/ml for GA, SU and SA, and 2.5 μg/ml for SHA. The method was applied to the study of salicylic acid metabolism in the rat.

ISSN:0003-2719    

DOI:10.1080/00032718808066333

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

A stability-indicating HPLC analytical method for the anticancer agent dibromodulcitol (DBD, Mitolactol, NSC-104800) has been developed that will completely resolve the compound from its degradation products. A 5 μm octadecylsilane analytical column was used in conjunction with a refractive index detector, with a mobile phase of 98:2 water/methanol. The limit of DBD detection was determined to be 250 ng (5 μg/ml) with a signal to noise ratio of 2:1. Intraday variation of the method, as percent relative standard deviation, was 4.37% (12.5 μg/ml) and 0.973% (250 μg/ml), and interday variation was 3.93% (250 μg/ml). Comparison with potentiometric titration of bromide after digestion of DBD with NaOH indicated that the method was more sensitive and specific than titration. The method has been used in tablet content analysis, as well as degradation studies of DBD in solution.

ISSN:0003-2719    

DOI:10.1080/00032718808066334

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

A rapid, sensitive and specific HPLC assay for the determination of ampicillin in human urine is developed.

ISSN:0003-2719    

DOI:10.1080/00032718808066335

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

A new spectrophotometric procedure has been developed for determination of penicillamine. It is based on reaction with nitrite and Co(II) ions and recording of the spectrum of the complex formed in 50% ethanol at 250 nm.

ISSN:0003-2719    

DOI:10.1080/00032718808066336

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

A direct UV spectrophotometric method has been developed for determination of antimony (III) antibilharzial compounds. The method has been successfully applied for the assay of five antibilharzial drugs.

ISSN:0003-2719    

DOI:10.1080/00032718808066337

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

A new series of reagents, N-phenyl-2-furylacrylohydroxamic acid and its eight analogues, together with eight pyridylazo reagents, were explored for the selective extraction and sensitive spectrophotometric determination of bismuth (III) in standard alloys and environmental matrices. Bismuth was first extracted with a hydroxamic acid into chloroform and a pyridylazo reagent was added to the extract to form an intensely coloured ternary complex for spectrophotometric analysis. The combination of N-p-methoxyphenyl-2-furylacrylohydroxamic acid (MFHA) and 5-iodo-5-(dimethylamino)-2-(2-pyridylazo) phenol (IDEPAP) provided the maximum selectivity and sensitivity (ϵ=6.5 × 1041 mol−1cm−1at 590 nm). The enrichment attained through solvent extraction together with the intense colour of the ternary complex enabled analysis of bismuth at levels of 1ppb (0.001 ppm) and lower.

ISSN:0003-2719    

DOI:10.1080/00032718808066338

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

Herbicidal carboxylic acids were analyzed via ECD gas chromatography of their pentafluorobenzyl esters. The derivatives were formed by direct injection of a mixture of the acids and pentafluorobenzyl bromide in acetone; yields showed marked dependence on pKa of the acids. Carboxylic acids which have pKa values greater than 4.5 yielded the corresponding derivatives in poor yield unless triethylamine is included in the mixture. The procedure is fast and particularly convenient for low-level screening, identification and analysis of highly acidic chlorobenzoic, chlorophenoxyalkanoic, and arylacetic acids in the presence of less acidic carboxylic acids and phenols.

ISSN:0003-2719    

DOI:10.1080/00032718808066339

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor