Separation of major mononitro-aromatic compounds by reversed-phase high-performance liquid chromatography.

A simple analytical method was developed to determine p-nitrochlorobenzene (p-NCB) in working environmental air by reversed-phase high-performance liquid chromatography (HPLC). Nitrobenzene, nitrotoluene isomers, and NCB isomers were separated and p-NCB was determined by reversed-phase HPLC as follows: column; Hitachi gel #3056 (4.0 mm I.D. x 150 mm), mobile phase; 2-propanol: water (40:60, v/ v) with a flow rate of 0.8 ml/min, column temperature; 50 degrees C, detector; UV detector at 270 nm. Nitrobenzene, o-, p-nitrotoluene, and o-, m-NCB were separated from p-NCB, but m-nitrotoluene could not be completely separated from p-NCB. The limit of detection (signal-to-noise ratio of 3:1) of p-NCB was 0.3 ng. Repeatability of the HPLC method was excellent. The HPLC method enabled to determine one-tenth of the administrative level (1 mg/m3) of p-NCB, since the lower limit of determination was 0.05 mg/m3. Therefore, the present HPLC method proved to be applicable to the determination of p-NCB in working environmental air.