Quantification of neurotransmitter amino acids by capillary electrophoresis laser-induced fluorescence detection in biological fluids.
The role of neurotransmitter amino acids (NAAs) in the functioning of the nervous system has been the focus of increasingly intense research over the past several years. Among the various amino acids that have important roles as neurotransmitters, there are alanine (Ala), glutamic acid (Glu), aspartic acid (Asp), serine (Ser), taurine (Tau) and glycine (Gly). NAAs are present in plasma, cells and--at trace levels--in all biological fluids, but complex components in biological matrices make it difficult to determine them in biological samples. We describe a new capillary electrophoresis (CE) method with laser-induced fluorescence detection by which analytes are resolved in less than 12 minutes in a 18 mmol/L phosphate run buffer at pH 11.6. The use of elevated temperatures during sample derivatization leads to a drastic reduction in the reaction time, down to 20 min, compared to the 6-14 h usually described for reactions between FITC and amino acids at room temperature. In order to demonstrate its wide range of applications, the method was applied to the analysis of NAA in human plasma and in other sample types, such as red blood cells, urine, cultured cells, cerebrospinal fluid, saliva and vitreous humor, thus avoiding the typical limitations of other methods, which are normally suitable for use with only one or two matrix types.
Zinellu
Angelo
A
Department Biomedical Sciences and Centre of Excellence for Biotechnology Development and Biodiversity Research, University of Sassari, Viale San Pietro 43/B, 07100 Sassari, Italy.
Sotgia
Salvatore
S
Pisanu
Elisabetta
E
Scanu
Bastianina
B
Sanna
Manuela
M
Usai
Maria Franca
MF
Chessa
Roberto
R
Deiana
Luca
L
Carru
Ciriaco
C
D000596:Amino Acids / Q000032:analysis* / Q000097:blood / Q000134:cerebrospinal fluid / Q000652:urine; D019075:Electrophoresis, Capillary / Q000379:methods*; D005453:Fluorescence; D006801:Humans; D018377:Neurotransmitter Agents / Q000032:analysis* / Q000097:blood / Q000134:cerebrospinal fluid / Q000652:urine
D000596:Amino Acids; D018377:Neurotransmitter Agents