Analytical Sciences


Abstract − Analytical Sciences, 22(1), 137 (2006).

Development of Sequential Injection-Lab-at-Valve (SI-LAV) Micro-Extraction Instrumentation for the Spectrophotometric Determination of an Anionic Surfactant
Rodjana BURAKHAM,* Jaroon JAKMUNEE,** and Kate GRUDPAN**
*Department of Chemistry, Faculty of Science, Khon Kaen University, Khon Kaen 40002, Thailand
**Department of Chemistry, Faculty of Science and Institute for Science and Technology Research and Development, Chiang Mai University, Chiang Mai 50200, Thailand
The development of instrumentation for sequential injection analysis with a “lab-at-valve” (SIA-LAV) micro-extraction system is presented. The extractive determination of an anionic surfactant using methylene blue was selected as a model. Sample, reagents and organic solvent were sequentially aspirated into an extraction coil connected to the center of a selection valve, where extraction took place by flow reversal. The aqueous and organic phases were separated in a LAV unit attached to one port of the valve. The LAV unit situated a fiber-optic spectrophotometer to monitor the absorbance change of the extract product in the organic phase. The developed SIA-LAV system offers an alternative micro-total analysis system for automated micro-extraction.