AN AUTOMATIC PHOTOMETRIC-METHOD WITH HIGH-PRECISION BY GRADUALLY DILUTING A SAMPLE

Authors
Citation
Am. Tan et Cl. Xiao, AN AUTOMATIC PHOTOMETRIC-METHOD WITH HIGH-PRECISION BY GRADUALLY DILUTING A SAMPLE, Talanta, 44(11), 1997, pp. 2081-2086
Citations number
10
Journal title
Talanta
ISSN journal
00399140 → ACNP
Volume
44
Issue
11
Year of publication
1997
Pages
2081 - 2086
Database
ISI
SICI code
0039-9140(1997)44:11<2081:AAPWHB>2.0.ZU;2-6
Abstract
An automatic photometric method to increase the precision of measureme nt is proposed, which is based on the injection of a very small volume of sample by rotary valve and the subsequent homogeneous mixing in a small reaction cell made of glass of the sample with a color-developin g reagent gradually delivered by a syringe piston pump until the absor bance of the mixture approaches 0.434, where the lowest relative error in the concentration locates. This photometric method is characterist ic of uniformly high precision, low sample and reagent consumption, an d high sampling rate of 30 samples per h. The other advantages of this method include easy calibration with only one standard solution and n o strict requirements on photometric components. While applied for the determination of cobalt ranging from 0.21 to 1.43 g l(-1), the relati ve standard deviations are all below 0.4%. (C) 1997 Elsevier Science B .V.