Amino Acid Measurements from a High Conductivity Matrix by Gradient Elution Isotachophoresis

• Published in: Chromatographia Vol. 70; no. 1-2; pp. 151 - 156
• Main Authors: Vyas, Chandni A., Mamunooru, Manasa, Shackman, Jonathan G.
• Format: Journal Article
• Language: English
• Published: Wiesbaden Vieweg Verlag 01-07-2009; Springer
• Subjects: Analytical Chemistry; Biological and medical sciences; Chemistry; Chemistry and Materials Science; Chromatography; Investigative techniques, diagnostic techniques (general aspects); Laboratory Medicine; Medical sciences; Miscellaneous. Technology; Original; Pathology. Cytology. Biochemistry. Spectrometry. Miscellaneous investigative techniques; Pharmacy; Proteomics; Isotachophoresis; Aspartate and glutamate; Capillary electrophoresis; Microdialysate; Trace analysis; Biological fluid; Elution; Gradient; Chemical analysis; Aspartate; Cerebrospinal fluid; Derivatization; Glutamate; Chemical enrichment; Ultraviolet detector; Microdialysis; Clinical biology; Excitatory aminoacid; Neurotransmitter
• ISSN: 0009-5893; 1612-1112
• DOI: 10.1365/s10337-009-1122-z

Gradient elution isotachophoresis has demonstrated efficient enrichment and separation of many analytes, from small molecules to proteins. Prior work has shown analyte enrichment is most efficient with low conductivity samples and high conductivity leading electrolytes. This work investigates the applicability to small biomolecule measurements in highly saline matrices, such as found in biological fluids. The method was applied to the enrichment and separation of physiologically relevant concentrations of chromophore-derivatized aspartate and glutamate in artificial cerebrospinal fluid. Carboxyfluorescein-labeled species yielded the best sensitivity and resolution, with glutamate and aspartate LODs of 120 and 180 nM, respectively.