摘要:

A two step anodic stripping voltammetry of a single sample of water which has been made 0.1Nin HC104, is useful for simultaneously detecting Hg+2, Zn+2, Cd+2, Pb+2, Cu+2, Co+2and Ni+2. In the first step mercury is determined by deposition onto a bare glassy carbon electrode (GCE) with subsequent stripping, and in the second step the remainder of the metal ions above are sought by deposition onto a mercury plated GCE and subsequent stripping. With a deposition time of 72.82 min the detection sensitivity varies from about 0.2 ppb for cobalt to about 10 ppb for zinc. Silver, tin and chloride were found to be interferences in the detection of some of the metal ions.

ISSN:0003-2719    

DOI:10.1080/00032717208062151

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

The design of a new instrument for routine analysis of electroactive substances is presented. The instrument is a potentiostat in which potential control is maintained by varying the rate of delivery of current pulses of uniform charge content to a small electrochemical cell. Digital readout of the concentration in desired units is obtained by counting and displaying the number of current impulses. The entire analysis consists of introducing a sample, pressing the potentiostat button and reading the result within 3–5 seconds - hence the name, “push-button analyser”. A block diagram, schematic diagrams and parts list are included.

ISSN:0003-2719    

DOI:10.1080/00032717208062152

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

An electrochemical technique for the rapid clinical analysis of serum uric acid is described. This method, in contrast to the widely used phosphotungstate and uricase methods, requires no sample manipulation and uses no reagents. Uric acid concentration is read out digitally in four seconds.

ISSN:0003-2719    

DOI:10.1080/00032717208062153

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

Titanocene nitrogen fixation in tetrahydrofuran was significantly affected by traces of water. Water was reduced to hydrogen by titanocene monochloride. In turn, hydrogen was reduced to hydride by titanocene. Analogy with nitrogenase catalysis is discussed.

ISSN:0003-2719    

DOI:10.1080/00032717208062154

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

The 16α-methyl group in dexamethasone increases drastically the steric hindrance to reaction of both the 20-ketone and 17α-hydroxyl groups, as shown by kinetic studies with GC-MS techniques. A procedure is described for the preparation of the MO derivative (reaction et 60[ddot]C for 3 hr) and complete conversion of all hydroxyl groups to TMS ether groups (reaction at 100[ddot]C for 6 hr). The resulting MO-TMS derivative is thermostable and suitable for use in GC-MS methods. The procedures usually employed in urinary steroid studies are satisfactory for prednisone and prednisolone.

ISSN:0003-2719    

DOI:10.1080/00032717208062155

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

This report describes a radioimmunoassay method for the measurement of unconjugated 17-hydroxypregnenolone (17-5δ-P) in plasma. Utilizing a highly specific 17-5δ-P antiserum combined with a one step celite microcolumn chromatographic system, we have measured this steroid accurately in small aliquots of plasma from both male and female subjects. The plasma levels of 17-5δ-P obtained by this method agreed well with levels observed in adult men and women, using two other techniques. Compared with the latters, however, the present method offered a tenfold greater sensitivity and a better precision.

ISSN:0003-2719    

DOI:10.1080/00032717208062156

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

Successful gas chromatographic elution of a range of diene tricar-bonyl from complexes has been achieved for the first time. Provided that precautions were taken to exclude air and prevent prolonged exposure to light many of those supposedly ‘unstable’ compounds could be gas chroma-tographed at temperatures up to 150[ddot] with no apparent thermal decomposition. Teflon columns employing E-301 methyl silicone gum as stationary phase gave best results, symmetrical gausssian peaks being obtained for most compounds with quantitative response to the microgram level.

ISSN:0003-2719    

DOI:10.1080/00032717208062157

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

The temperature dependence of the electron capture process was investigated for a series of divalent sulfur compounds. The electron affinity and/or the activation energy for the electron capture reaction were calculated for individual compounds by plotting In KT3/2vs. 1/T, where K is the electron capture coefficient and T is the absolute temperature in the detector. The correlation between these values and chemical structure was discussed by means of 3d orbital resonance of the sulfur atom.

ISSN:0003-2719    

DOI:10.1080/00032717208062158

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

An initial investigation of ion-exchange membranes as trace metal concentrating devices in natural water systems and their suitability as targets for proton-excited x-ray flurorescence (PEXF) is reported. Element maps (Z=19 to Z=85) for various locations along a river were obtained with acceptable sensitivity in an irradiation period of 300 sec. The membrane used is mechanically stablein situand is not destroyed by the 3 Mev (50 na)proton beamused in the study.

ISSN:0003-2719    

DOI:10.1080/00032717208062159

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

ISSN:0003-2719    

DOI:10.1080/00032717208062150

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor