Migration markers for capillary isotachophoresis of ribonucleotides

✍ Scribed by Shujun Chen; Milton L. Lee

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 137 KB
• Volume: 10
• Category: Article
• ISSN: 1040-7685
• DOI: 10.1002/(sici)1520-667x(1998)10:5<423::aid-mcs5>3.0.co;2-i

✦ Synopsis

2-Chloropropionic, glyoxylic, and levulinic acids were evaluated as migration markers for isotachophoresis of ribonucleotides on Ucon-coated capillaries. The effects of leading electrolyte pH and concentration on the elution sequence of ribonucleotides were studied. 2-Chloropropionic and levulinic acids were effective at pH 4.50 for 10 mM leading electrolyte, while glyoxylic and levulinic acids worked best at pH 4.50 for 5 and 1 mM leading electrolytes. These migration markers divided the ribonucleotides into three groups: triphosphate, diphosphate, and monophosphate. At pH values lower than 4.50, mixed-analyte zones were formed. At pH values higher than 4.50, zones mixed with impurities were formed. The leading electrolyte concentration affected the effective mobility, elution sequence, concentration effects, and separation speed. Low leading electrolyte concentration Ž . ca. 1 mM provided high sensitivity and fast separation. The origin of peaklike Ž . bands in capillary isotachophoresis CITP is attributed to boundary overlap at the band edges. When a dilute sample is analyzed, the band width is mainly defined by the boundary widths. The boundary width is dependent on the electric field strength, temperature, and difference in effective mobilities of the two separands. High electric field strength, low temperature, and large difference in effective mobilities favor narrow boundaries, resulting in high sensitivity and fast separation.