Taurine determination by capillary electrophoresis with laser-induced fluorescence detection: from clinical field to quality food applications.
In this work we describe a new method for taurine quantification in plasma by capillary electrophoresis laser-induced fluorescence detection. Taurine is derivatized with fluorescein isothiocyanate at 100 degrees C in 20 min. These conditions allow to reduce the pre-analytical times and to derivatize quantitatively the taurine contained in the reaction mixture, contrary to the room temperature derivatization commonly adopted. FITC-taurine adduct is analyzed in an uncoated fused-silica capillary, 75 mum ID and 40 cm effective length using a 20 mmol/L tribasic sodium phosphate buffer pH 11.8, at 22 kV. To avoid the typical problems due to instability of FITC-adduct, we use the homocysteic acid as internal standard. The loss of FITC-taurine signal during the sequence analysis is compensated by the same loss of FITC-internal standard adduct, thus giving a noteworthy improvement in the assay precision. The method shows a good reproducibility of the migration times (coefficient of variation, CV%, 1.93) and the peak areas (CV%, 3.65). Intra- and interassay CV were 4.63 and 6.44%, respectively, and analytical recovery was between 98.1 and 102.3%. Assay application was tested measuring taurine plasma levels in 50 healthy volunteers in which a mean value of 60.2 +/- 17.9 micromol/L was found. Moreover, the applicability of the method was also checked on energy drinks and milk.
Zinellu
Angelo
A
Department of Biomedical Sciences, University of Sassari, Sassari, SS, Italy. angelozinellu@libero.it
Sotgia
Salvatore
S
Scanu
Bastianina
B
Bastianina
Scanu
S
Chessa
Roberto
R
Gaspa
Leonardo
L
Franconi
Flavia
F
Deiana
Luca
L
Carru
Ciriaco
C
D002138:Calibration; D019075:Electrophoresis, Capillary / Q000379:methods*; D005502:Food; D006801:Humans; D013050:Spectrometry, Fluorescence / Q000379:methods*; D013654:Taurine / Q000032:analysis* / Q000737:chemistry*
D013654:Taurine