摘要:

A sensitive choline sensor was developed on the basis of a chemiluminometric bienzyme optrode. Choline oxidase (ChOx) and fungal peroxidase (FPOD) were covalently immobilized on a preactivated nylon membrane. The addition of polyethylenimine to the mixed enzyme solution before the immobilization combined with the crosslinking by gaseous glutardialdehyde improves both the long-term stability and the sensitivity. Choline can be detected in the range between 10−6and 10−3M.

ISSN:0003-2719    

DOI:10.1080/00032719608000387

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

A PVC membrane electrode selective for trimethoprimium cation based on trimethoprimium-phosphotungstate (TM)3PT ion associate is prepared. The electrode shows a linear response with Nernstian slope over the range of 2.7×10−6-10−2M. Calibration graph slope of the electrode is 59 mV/TM concentration decade when preconditioned by soaking in distilled water for 1 hour to 15 days. The electrode has working pH range of 1.8 to 6.3 and exhibits good selectivity for the trimethoprim with respect to a large number of inorganic cations and organic substances of biological importance. TM is determined successfully in pure solutions and in tablets using the standard additions methods.

ISSN:0003-2719    

DOI:10.1080/00032719608000388

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

The replacement of the quartz halogen lamp of an ORD fluorometer with a high brightness blue-light-emitting diode enhanced evanescent excitation of benzoylecgonine-fluorescein bound to the mAbs immobilized on quartz fibers and gave stronger optical signals.

ISSN:0003-2719    

DOI:10.1080/00032719608000389

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

A liquid membrane electrode based on metomidate - dipicrylamine ion-pair complex, dissolved in nitrobenzene as solvent is proposed for the determination of metomidate - an anesthetic drug. The linear response covers the range from 10−2- 10−6M metomidate solution, with a slope of 55.98 mV/decade (pH range 1.75 to 4.50). The detection limit is 3.31 × 10−9M. The electrode shows stability, good reproducibility and fast response. The selectivity of the electrode is also good with the exception of mianserin which is strong interfering ion. These characteristics of the electrode made it useful for the determination of metomidate through direct and indirect potentiometric methods. Through indirect determined potentiometric method, metomidate can be determined with an average recovery of 98.52% and a relative standard deviation of 0.93%.

ISSN:0003-2719    

DOI:10.1080/00032719608000390

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

Chloride in human body fluids is physiologically important. In this paper, chloride in human body fluids, including blood serum, urine, and cerebrospinal fluid (CSF), was determined by ion chromatography with a serial piezoelectric quartz crystal (SPQC) as detector, and 2.0 mmol/L potassium hydrogen phthalate (KHP) as mobile phase. Also discussed was sample pretreatment for the determination. The method is rather simple, rapid, accurate, and reproducible. Body fluids of patients were analyzed using both the presented method and classical method, and the obtained results well agreed with each other.

ISSN:0003-2719    

DOI:10.1080/00032719608000391

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

A new type of surface acoustic wave impedance sensor based on a conductance-surface acoustic wave frequency reponse was applied to assay the activity of acid phosphatase. Using cytidine-5′-monophosphate (5′-CMP) as a substrate, the Michaelis constant and the corresponding maximum initial rate were estimated to be 4.13×10−3and 9827 Hz/min, respectively. A linear relationship between frequency response and enzyme concentration was obtained in the range up to 250 μg/ml of acid phosphatase, at 25°C and pH 4.5. The experimental detection limit of acid phosphatase (within 1 min) was 0.9 min/ml and the recovery of the sensor system ranged from 94% to 106% (n = 6). Some other factors such as temperature, pH value and the effects of some metal ions were also discussed.

ISSN:0003-2719    

DOI:10.1080/00032719608000392

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

Thermal stabilization of several volatile elements (antimony, arsenic, bismuth, cadmium, lead, selenium, tin, and thallium) in biological digests, solubilized hair and diluted urine in the presence of mixed modifiers: palladium-tungsten and palladium-tungsten-ammonium nitrate (for urine) has been studied. ETAAS procedures for analysis of biological tissues and urine have been elaborated. Simple techniques for pre-instrumental treatment and fast temperature programs are expedited. Applications to different biological reference materials have been demonstrated. The relative errors and RSDs are less than 10%, and the analyte recoveries are within 96 and 108%.

ISSN:0003-2719    

DOI:10.1080/00032719608000393

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

The polarographic and voltammetric behaviour of mitoxantrone has been studied. A well-defined linear sweep voltammetric peak was found at -0.83 V (vs. SCE) in HEPES buffer (50 mmol/L, pH 7.0). The experimental results prove that the reduction peak of mitoxantrone has adsorptive characteristics. A single-sweep oscillopolarographic method was developed for the determination of mitoxantrone in human serum and urine. The peak current (iP) is proportional to concentration in the range 5 × 10−7-5 × 10−5mol/L.

ISSN:0003-2719    

DOI:10.1080/00032719608000394

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

The first and second derivative spectrophotometric methods have been developed for the determination of flavonoids chrysin and quercetin. The amplitudes in the first derivative spectrophotometric spectra at 256 nm and in the second derivative spectra at 268 nm were selected to determine chrysin, while the amplitudes at 233 and 269 nm in the first and at 241, 258, 387 and 403 nm in the second derivative spectra were chosen for the determination of quercetin. A linear relationship between derivative amplitudes and a concentration of compounds was found. Beer's law is obeyed over a concentration range of 2–20 μg.mL−1for both drug components. The method is rapid, simple, sensitive and does not require a separation step.

ISSN:0003-2719    

DOI:10.1080/00032719608000395

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

A selective, highly sensitive fluorimetric method is described for the determination of three α-aminocephalosporins, namely cephalexin, cefaclor and cephradine. Other cephalosporins free from the amino group did not interfere with the assay. The proposed method involves acid-hydrolysis of the drugs and subsequent alkalinization before measurement. The different experimental parameters affecting the fluorescence intensity were carefully studied and incorporated into the procedure. The method permits the determination of 0.02–0.40, 0.04–0.60 and 0.08–0.80 ug.ml−1for cephalexin, cefaclor and cephradine respectively with minimum detectability of 0.2 ng.ml−1for all cephalosporins. The proposed method was successfully applied to the determination of these drugs in formulations and biological fluids. The advantages of the described method over other existing methods were discussed. A route for the reaction pathway proposed.

ISSN:0003-2719    

DOI:10.1080/00032719608000396

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor