Determination of unconjugated aromatic acids in urine by capillary electrophoresis with dual electrochemical detection--potential application in fast diagnosis of phenylketonuria.
A novel method of CE coupled with dual electrochemical detection has been developed for the determination of pathological metabolites of phenylalanine in urine samples. Factors influencing the separation and detection were examined and optimized. Five aromatic acid metabolites and a major coexisting interfering compound uric acid could be well separated within 23 min at a separation voltage of 16 kV using a 35 mmol/L SDS/60 mmol/L H(3)BO(3)-Na(2)B(4)O(7) running buffer (pH 8.2). Highly linear response was obtained for these five biomarker compounds over three orders of magnitude with detection limits ranging from 6.6 to 0.064 μg/mL (S/N=3). The average recovery and RSD were within the range of 92.6-121.0 and 1.0-12.0%, respectively. The proposed method has been used to detect the unconjugated aromatic acids simultaneously in urine samples with the advantages of obtaining more information about target analytes and avoiding redundant measurements and high assay cost, thus could find potential applications involving assays of biomarker compounds for the purpose of fast diagnose of some metabolic diseases including phenylketonuria.
Zhang
Dong-li
DL
Department of Chemistry, East China Normal University, Shanghai, P. R. China.
Li
Wen-li
WL
Zhang
Jun-bo
JB
Tang
Wan-rong
WR
Chen
Xiao-fei
XF
Cao
Kai-wen
KW
Chu
Qing-cui
QC
Ye
Jian-nong
JN
D000328:Adult; D015415:Biomarkers / Q000652:urine*; D004566:Electrodes; D019075:Electrophoresis, Capillary / Q000379:methods*; D005260:Female; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007223:Infant; D016014:Linear Models; D008297:Male; D010648:Phenylacetates / Q000652:urine*; D010649:Phenylalanine / Q000378:metabolism; D010661:Phenylketonurias / Q000175:diagnosis / Q000652:urine; D010667:Phenylpyruvic Acids / Q000652:urine*; D011247:Pregnancy; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012967:Sodium Dodecyl Sulfate
D015415:Biomarkers; D010648:Phenylacetates; D010667:Phenylpyruvic Acids; D012967:Sodium Dodecyl Sulfate; D010649:Phenylalanine