Library Open Repository

Buffered chromate electrolytes for separation and indirect absorbance detection of inorganic anions in capillary electrophoresis

Downloads

Downloads per month over past year

Doble, P and Macka, M and Andersson, P and Haddad, PR (1997) Buffered chromate electrolytes for separation and indirect absorbance detection of inorganic anions in capillary electrophoresis. Analytical Communications, 34 (11). pp. 351-353. ISSN 1359-7337

[img] PDF
164.pdf | Request a copy
Full text restricted
Available under University of Tasmania Standard License.

Abstract

Chromate is the most commonly used carrier electrolyte for the determination of low molecular weight and inorganic anions by capillary electrophoresis. However, chromate electrolytes are usually prepared in the sodium form and consequently have poor buffering capacity. Addition of anionic buffers that introduce competing co-anions is undesirable because they can reduce the sensitivity of indirect detection and cause interfering system peaks. An approach is demonstrated to buffer a chromate electrolyte by using a suitable buffering base as a counter-ion of the chromate. This approach does not introduce any co-anions into the background electrolyte, which is prepared by titrating the acid form of chromate to the pKa of the added base. Two buffered electrolytes were investigated containing tris(hydroxymethyl)amino- ethane (pKa = 8.5) or diethanolamine, (pKa = 9.2). The analytical performance characteristics of the buffered electrolytes were compared with the unbuffered chromate electrolyte. Both systems showed similar separation selectivity, efficiency and detection sensitivity, but the buffered electrolytes showed superior repeatability for migration times and peak areas, as well as a significantly greater tolerance to alkaline sample matrices.

Item Type: Article
Journal or Publication Title: Analytical Communications
Page Range: pp. 351-353
ISSN: 1359-7337
Identification Number - DOI: 10.1039/a706001g
Additional Information: © 1997 Royal Society of Chemistry
Date Deposited: 14 Nov 2008 00:10
Last Modified: 18 Nov 2014 03:53
URI: http://eprints.utas.edu.au/id/eprint/8008
Item Statistics: View statistics for this item

Repository Staff Only (login required)

Item Control Page Item Control Page