Evaluation of a capillary gas chromatographic impurity test procedure for 4-hexylaniline.
A capillary gas chromatographic test procedure for the detection and quantitation of impurities in the bulk intermediate, 4-hexylaniline, is evaluated and found to be accurate and precise. 4-Hexylaniline is dissolved in methanol and chromatographed isothermally at a temperature of 195 degrees C on a 60-m x 0.32-mm 85% polyethylene glycol-15% dimethylsilicone blend (DX-4) film column. A flame ionization detector is used, and the impurities in the parent compound are estimated from peak areas on a percent basis compared with the area of the parent peak in the chromatogram. Response factors are determined for the known impurities. Validation of this test method includes a recovery study of known impurity spiked samples fortified in the range of 0.1-1% (w/w). A repeatability study is performed, consisting of the analysis of two different synthetic batch lots of 4-hexylaniline analyzed over three experimental run days using two chromatographic columns of different manufacturing lots. These data and other aspects of this test procedure are discussed.
B'Hymer
C
C
University of Cincinnati, Mail Location 0172, Cincinnati, OH 45221-0172, USA. bhymerc@email.uc.edu