HPLC with fluorescence detection of urinary phenol, cresols and xylenols using 4-(4,5-diphenyl-1H-imidazol-2-yl)benzoyl chloride as a fluorescence labeling reagent.
A simple and sensitive HPLC method for the determination of phenolic compounds, i.e., phenol (Phe), cresols (Cres) and xylenols (Xyls), was developed. After a pre-column fluorescence derivatization of these compounds with 4-(4,5-diphenyl-1H-imidazol-2-yl)benzoyl chloride (DIB-Cl) at 60 degrees C for 30 min, 11 DIB derivatives were successfully separated within 50 min with an ODS column using CH3CN-H2O-CH3OH (25 + 22 + 53, v/v) as the eluent. The detection limits of DIB derivatives at a signal-to-noise ratio of 3 ranged from 0.15 to 1.09 microM (0.2-1.6 pmol per 20 microliters). The precision of the proposed method for both within- and between-day assays of free and total phenol related compounds was satisfactory (RSD < 9.5%). By the proposed method, Phe and p-Cre could be detected in normal urine samples, and the calculated concentrations of free Phe and p-Cre in unhydrolysed urine samples were 1.5 +/- 1.3 and 23.9 +/- 24.3 microM and those of total Phe and p-Cre in hydrolysed urine samples were 87.3 +/- 81.2 and 200.7 +/- 195.4 microM (n = 21), respectively.
Nakashima
K
K
School of Pharmaceutical Sciences, Nagasaki University, Japan.
Kinoshita
S
S
Wada
M
M
Kuroda
N
N
Baeyens
W R
WR
D001565:Benzoates; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D003408:Cresols / Q000652:urine; D005453:Fluorescence; D007093:Imidazoles; D007202:Indicators and Reagents; D010636:Phenols / Q000652:urine*
C114684:4-(4,5-diphenyl-1H-imidazol-2-yl)benzoyl chloride; D001565:Benzoates; D003408:Cresols; D007093:Imidazoles; D007202:Indicators and Reagents; D010636:Phenols