摘要:

A sensitive method for rapid determination of inorganic phosphate in water samples is described which is based on a reaction between phosphomolybdate and resazurine; phosphomolybdrlte and p-rosolic acid. The molar absorptivities are 2867.5, 2656.9 at 495 and 470 nm with resazurine and p-rosolic acid reagents. Phosphate can be determirled in concentration range of 0.02 to 0.08 ppm, of 0.02 to 0.16 ppm with resazurine and p-rosolic acid reagents respectively.

ISSN:0003-2719    

DOI:10.1080/00032718708082231

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

Solvent extraction, spectrophotometric and atomic absorption spectrophotometric determination of tellurium-(IV) in nanogram levels are described. The tellurium(IV) forms yellow colored complex with N-phenylbenzohydroxamic acid (PBHA) which is extractable into chloroform from 7 M HCI04. Te-PBHA complex has a maximum absorbance at 345 nm with the molar absorptivity 3.5 × 1041 mol−1cm−1and Sandell's sensitivity 0.00365 μg/cm2. The tellurium(IV) is also determined in the range of 0.01 – 0.08 ppm by flameless atomic absorption spectrophotometry using GEC HG 900 vapor generation accessay. Effect of molarity, reagent concentrntions, diverse ions on the extraction of tellurium complex were studied. The tellurium was determined in presence of selenium and also in standerd samples.

ISSN:0003-2719    

DOI:10.1080/00032718708082232

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

A turbidimetric method was developed for the determination of 2–30 ppm nitrite after reacting with sultamic acid to produce sulfate which was coinverted to barium sulfate and measured turb idimetrically. Several diverse ions were found not to interfere. The interference by phosphate and sulfate was overcome by treating the sample with barium chloride prior to the addition of sulfamic acid and centrifuging.

ISSN:0003-2719    

DOI:10.1080/00032718708082233

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

A spectrophotmetric study of the Os(VIII) complex of a reagent 3,4-dihydro-4,4,6-t rimethy-2-(1H)-pyrimidinethione (DTPT) is presented. A violet complex Os (DTPT)4is formed in a strong acid solution which is soluble in water and shows maximum absorbance at 495 nm with molar absorptivity of 5.1×103l. mol−1.cm−1. Beer's law is obeyed up to 24 ppm of Os(VIII). Sandel's sensitivity of the reaction of Os(III) is 0.039 μg.cm−2per 0.001 absorbance unit. Hg(II), Pd(II), Ru(VIII), Cu(II) and S2-interfer

ISSN:0003-2719    

DOI:10.1080/00032718708082234

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

An ion-selective electrode based on a naturally ocurring carboxylic polyether antibiotic salinomycin is described which exhibits high Ba2+selectivity. The selectivity coefficients of the electrode based on salinomycin, log KpotBaCa, log KpotBaKand log KpotBaNaare −2.65, −2.86 and −3.55, respectively.

ISSN:0003-2719    

DOI:10.1080/00032718708082235

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

A new method for the measurement of the concentration of humic substances (HS) in seawater is described. The peak obtained by differential cathodic sweep voltammetry after HS adsorption in the presence of traces of molybdenum(VI) can be used for quantitative determination. Measurements using various electrochemical techniques (ACP, CV, ADPV, DPP) would indicate that the film adsorbed onto the electrode is the result of the adsorption of the organic substance in a first step followed in a subsequent step by the formation of a surface complex (Mo(VI)-HS)adsrather than the direct adsorption of the dissolved complex. The electrochemical mechanism corresponds to a one-electron reduction of the adsorbed (Mo(VI)-HS)adscomplex to the corresponding (Mo(V)-HS)adscomplex.

ISSN:0003-2719    

DOI:10.1080/00032718708082236

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

A linear image sensor combined with a microcomputer system was applied to the immunoassay for human immunoglobulin G (H-IgG) based on turbidimetry. Antibody bound latex beads (Ab-L) were reacted with H-IgG in a glass capillary (0.8mmΦ× 70mm). The light scattering intensity profilesalong the capillary were analyzed from the light intensities at each element of the image sensor. A good correlation was obtained between the normalized variation of light intensity at 15 min and the concentration of H-IgG in the range 5×10−85×10−10g.ml−1.

ISSN:0003-2719    

DOI:10.1080/00032718708082237

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

A microbial-FET alcohol sensor was developed using immobilized acetic acid bacteria, a gas permeable membrane and an Ion Sensitive Field Effect Transistor (ISFET). The acetic acid bacteria were immobilized on the gate of the ISFET in calcium alginate gel. Both ISFET-immobilized microorganisms and Ag/AgCl reference electrode were set into a small shell which was filled with inner buffer (5 mM tris-HC1 buffer containing 0.1 M CaC12, pH 7.0). The side wall of the shell was equipped with a gas permeable membrane to allow the passage of alcohol into the inner buffer. The alcohol sensor responded to 0.1 mM ethanol and a linear relationship was obtained between the initial rate of response (dVg/dt) and the logarithmic ethanol concentration in the range between 3 – 70 mM. The alcohol sensor specifically responded to ethanol, 1-propanol and 1-butanol but did not respond to methanol, secondary alcohols and other nutrients (sugars and organic acids). The alcohol sensor was stable at pH 2 – 12 and at 15 – 25°C for 15 hours.

ISSN:0003-2719    

DOI:10.1080/00032718708082238

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

A simple and rapid method for the determination of doxorubicin in plasma and urine by HPLC-EC is described. The method is accurate and precise and the limits of detection are 1 ng/ml for plasma and 10 ng/ml for urine. The method requires only l Ml of sample which is important in its application to clinical studies in infants and adolescents, since the amount of plasma is limited and a large number of samples are needed to define the pharmacokinetic parameters accurately. Both coulometric and amperometric were evaluated and the latter was preferred on the basis of detector selectivity. The methodology was applied to a pharmacokinetic study of doxorubicin given to patinets with osteogenic sarcoma. This study revealed that the disposition of doxorubicin in plasma and urine changes with repetitive dosing. Epidoxorubicin was used as an internal standard and the technique should be equally applicable to the analysis of this drug since the detector response and limits of detection were the same for both drugs.

ISSN:0003-2719    

DOI:10.1080/00032718708082239

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

A simple, fast and reproducible method for determination of chlorpromazine (CLP) is presented. Calibration curves are prepared for the 6.0 mol.dm−3solutions of 1.0×10−6to 1.0×10−4CLP which are oxidized with equivalent volumes of standard Ce+4solutions to a highly coloured (λmax=525nm.) semiquinone cation radical. Conventional photometric and photoacoustic techniques using carbon-black detection (CBD) gave consistent results and are used to calculate the CLP content of tablets and ampuls with a good precision, and an overall accuracy of 1.9% and ∼3% respectively.

ISSN:0003-2719    

DOI:10.1080/00032718708082240

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor