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971.
pH配位滴定法同时测定铜和锌 总被引:4,自引:0,他引:4
本文将多元线性回归法应用于pH配位滴定法中,提出了金属离子混合液中各组分同时测定的方法原理,并对铜,锌合成样品进行了测定,得到满意的结果。 相似文献
972.
973.
A novel application of an electrochemical biosensor is here employed as analytical method for the detection and presumptive identification of antimicrobial drug residues in milk. The measurement was based on carbon dioxide production rate in relation to inhibition of microbial grow (Escherichia coli ATCC 11303). In this pilot study quinolone and tetracycline residues have been taken into consideration because use of these last in livestock production has been identified as area of particular concern. The experimental approach and analytical method developed appear adequate for the purpose, and compared to older screening methods as, for example, the microbial inhibition assays and immunoassays, offers the advantages of (i) very short analysis time (about 120 min); (ii) smaller sample amount (approximately 0.5 mL); (iii) no sample treatment (iv) good precision; and (v) the possibility of following, in a continuous manner, the inhibition process. Moreover, sensitivity of electrochemical biosensor system is resulted very high considering that for all quinolones and tetracyclines investigated it has been possible detect a residue concentration below or equal to 25 μg L−1. Under this point of view, it must be considered that the maximum residue limits fixed by UE for quinolones and tetracyclines in milk are, at present, all higher of this concentration. 相似文献
974.
《Electroanalysis》2006,18(5):433-439
This paper presents the results of investigation on selectivity of the sulfur dioxide amperometric sensor with Nafion membrane in the presence of carbon monoxide and nitrogen dioxide as the interferents. There have been compared selectivity coefficients, for the sensors containing the following internal electrolytes: solution of sulfuric acid (concentration 5 mol dm?3) in pure water (A) and solution of sulfuric acid (concentration 5 mol dm?3) in mixed solvent dimethylsulfoxide‐water with an DMSO: H2O mole ratio of 1 : 2 (B). Values of the selectivity coefficients have been calculated based on the calibration curves. Analysis of both calibration curves and selectivity coefficients plays a significant role in optimization of a working point of a particular sensor. The investigated sensor operates in a three‐electrode system, where the working and counter electrodes are vacuum sublimation deposited on the membrane surface. 相似文献
975.
提出了一种用硅双结型色敏器件测量色温的方法.在合理的测控电路下,硅双结型色敏器件的电流对数比与实验灯泡的色温值呈良好的单值对应,经单片机处理后可以得到分段线性关系.通过对电流对数比与波长随线的数据拟合,结果表明,用硅双结型色敏器件测量色温,其测量温度可以到10^4K以上,精度可以达到10K.本文的方法与传统方法相比减少了工作量,降低了费用,具有通用性和实用价值. 相似文献
976.
The field of the rapid characterization of products by HS-MS is reviewed. The general principle of HS-MS systems consists of introducing volatile components present in the HS of a sample without prior chromatographic separation into the ionization chamber of a mass spectrometer. The spectrum resulting from simultaneous ionization and fragmentation of the mixture of molecules introduced constitutes a “fingerprint” that is characteristic of the product being analyzed. Exploitation of this spectral information allows one determine the composition of the sample. 相似文献
977.
pH值对壳聚糖/羧甲基壳聚糖水凝胶溶胀行为的影响 总被引:4,自引:0,他引:4
利用壳聚糖与羧甲基壳聚糖制备了一系列新型的水凝胶,研究了pH值对水凝胶溶胀度、微观结构和基团结构的影响.结果表明,壳聚糖与羧甲基壳聚糖水凝胶的溶胀行为和微观结构均表现出pH值敏感性,但随着羧基的引入,水凝胶的最低溶胀度从pH7.O移向pH3.O.红外光谱证明,水凝胶的pH敏感行为是由基团结构的变化引起的. 相似文献
978.
979.
980.
《Electroanalysis》2006,18(16):1614-1619
Tape casting is a feasible method for preparing ceramic tapes with different electrical and magnetic properties for multilayer ceramic devices. This paper describes the tape casting process for the preparation of a new kind of self‐standing carbon electrodes (SSCE) using different ratios of graphite and the organic additives generally used in the non‐aqueous tape casting process. 相似文献