Sensitive determination of 1- and 2-naphthol in human plasma by HPLC-fluorescence detection with 4-(4,5-diphenyl-1H-imidazol-2-yl)benzoyl chloride as a labeling reagent

✍ Scribed by Kaname Ohyama; Naoya Kishikawa; Kenji Matayoshi; Lawrence Asamoah Adutwum; Mitsuhiro Wada; Kenichiro Nakashima; Naotaka Kuroda

• Publisher: John Wiley and Sons
• Year: 2009
• Tongue: English
• Weight: 454 KB
• Volume: 32
• Category: Article
• ISSN: 1615-9306
• DOI: 10.1002/jssc.200900056

✦ Synopsis

Abstract

A sensitive HPLC‐fluorescence (FL) method with FL‐labeling reagent for simultaneous determination of 1‐ and 2‐naphthol was developed. The FL‐labeling reaction of naphthols with 4‐(4,5‐diphenyl‐1__H__‐imidazol‐2‐yl)benzoyl chloride (DIB‐Cl) was completed in 20 min at 40°C. The separation of DIB derivatives was achieved with an ODS column and isocratic elution. The LODs of 1‐ and 2‐naphthol were 16 fmol and 14 fmol/injection, respectively, which were 5‐fold and 14‐fold lower than those obtained by HPLC‐FL method using the native FL of naphthols. The DIB‐naphthol derivatives were stable for at least 24 h even when they were placed at room temperature. The proposed method was applied to the measurement of 1‐ and 2‐naphthol in human plasma with sufficient accuracy (90.8–109%) and precision (< 6.3%).