摘要:

Instrumental control of processes in the chemical and petroleum industries has been going on for some 50 years, but for much of that time the technique involved only single-function instruments that measured temperature, pressure or flow and actuated simple control mechanisms. By 1945 a number of people began to realize that this type of control was crude compared to what could be done using instrumentation that would continuously analyze a process stream and provide detailed information on its composition. These men, largely within the R and D areas of large industrial concerns, gathered groups around them capable of developing such powerful process instruments. These groups contained hybrid elements - physicists, mechanical engineers, electrical engineers and chemists - whose pooled skills created the analytical tools. Many of these instrumental creations, proven and improved in process applications, are now produced by instrument companies.

ISSN:0003-2719    

DOI:10.1080/00032717208064320

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

Trimethylsilyl ethers are shown to give sharp p. m. r. signals at τ 9.8-9.9 and to have distinct chemical shifts. The technique is useful for determining the number of hydroxyl groups in a molecule. Because each trimethylsilyl group consists of nine protons strong signals are obtained from small amounts of sample. The method is thus suitable for analyzing eluates collected by gas-liquid chromatography.

ISSN:0003-2719    

DOI:10.1080/00032717208064321

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

The sensitivity of antimony determination with atomic absorption spectrophotometry is enhanced to a large extent by introducing stibine gas into an argon-hydrogen flame. As a reducing agent, zinc tablet made from the zinc powder paste with water is successfully used for quantitative and rapid productions of stibine from antimony (III) solution. The sensitivity for 1% absorption of the signal is estimated to be about 0.004 ppm of antimony.

ISSN:0003-2719    

DOI:10.1080/00032717208064322

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

A simple, rapid method for the estimation of reduced inorganic sulfur in reduced environments such as lake sediments was developed. The method involves distillation in the presence of granular zinc and hydrochloric acid and determination of sulfide as the methylene blue complex. The method gives quantitative recovery of elemental sulfur, sulfide and thiosulfate, and partial recovery of other reduced forms of inorganic sulfur. Sulfate, persulfate and organic forms of sulfur are not determined by the method developed. The method is sensitive and highly precise, and has been found to be very useful in evaluating the sulfur status of lake sediments.

ISSN:0003-2719    

DOI:10.1080/00032717208064323

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

Two techniques involving electrodeposition of Cu on a carbon rod (CR) prior to atomic absorption (AA) analysis are described. Thein situtechnique involves electrodeposition from ul samples contained in the well of the CR in an attempt to decrease matrix effects. The bulk electrolysis technique allows preconcentration of Cu on the CR from very dilute metal ion solutions. Analysis of Cu in solutions as dilute as 1.6 × 10−10M (70 ml volume) appears possible.

ISSN:0003-2719    

DOI:10.1080/00032717208064324

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

The use of hydrophobic gel particles containing an organic solvent solution of chelating agents is described. With the use of a column of such gel particles, it is possible to trap or concentrate metal ions selectively on the gel particles from very dilute aqueous solution. A method for the semi-quantitative determination of trace amount of metal ions is proposed.

ISSN:0003-2719    

DOI:10.1080/00032717208064325

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

A thin layer chromatographic procedure has been developed for the rapid detection of anthracene photooxidation products. Thus anthracene, anthraquinone, alizarin, quinizarin, and chrysazine were separated by the 1 ppm level by ascending T. L. C. on silica gel with benzene-carbon tetrachloride - acetic acid (50:75:0.8) as the solvent system.

ISSN:0003-2719    

DOI:10.1080/00032717208064326

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

Embedded in soils or immersed in a soil/solution system solid state ion selective electrodes, the Selectrodes, were used in continuous measurements of the activities of hydrogen, chloride and copper (III) ions of the solution phase. The total copper (II) concentration of the solution phase was assayed by the standard addition technique. Cation exchange isotherms were directly obtained by means of two pH-Selectrodes, one of which being charged with the exchanger material. The potentialities of “in situ” use of Selectrodes in soil-plant relationship work are emphazised.

ISSN:0003-2719    

DOI:10.1080/00032717208064327

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

A.C., D. C. and derivative pulse polarography of lead-tropolone complexes has been studied. It has been shown that the application of usual treatments for complexation in d. c. polarography are invalid in this system, where the irreversible wave in presence of the ligand is a composite step. It seems generally advisable to apply derivative pulse or a.c. polarography before using non-reversible d.c. steps for evaluation of K and p.

ISSN:0003-2719    

DOI:10.1080/00032717208064328

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

The concentration of35SO2in air can be measured by reacting with Pbo2to form Pb35SO4. A method was developed which is suitable for rapid, high-protection radioassaying of35SO42-on the surface of Pbo2. The surface35SO42-was extracted with a quaternary alkylammonium hydroxide in toluene and counted in an organic liquid scintillator solution with an efficiency of approximately 94%, which was constant for 30 days when corrected for natural decay. More than 99.5% of the surface sulfate was extracted in less than 5 minutes for quaternary alkylammonium concentrations 600 times in excess. This technique was shown superior to gas-flow proportional counting of the PbO2surface.

ISSN:0003-2719    

DOI:10.1080/00032717208064329

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor