Fully automated quantitative analysis of chloroaniline in personal cleansing liquid finished products

This presentation addresses an automated quantitative analysis designed for determination of chloroanilines (CA) in personal cleansing (PC) liquid products containing trichlorocarbonilide (TCC). These materials may be present as impurities in the germicides as used, or they may be formed from the germicides during processing. This is a fully automated analysis which covers everything from sample preparation to determination of CA at the parts per million level. The CA is diazotizated by addition of sodium nitrite. After a prescribed reaction time, the excess nitrous acid is destroyed with ammonium sulfamate. The diazotizated CA is derivatized with naphthylethylene diamine and the level determined by difference in the UV-VIS absorption at approximately on peak (555 nm) and background (660 nm). Linearity, accuracy, and precision ensure the validity of the robotics method. The method has a linearity working range from 0 to 100 ppm (correlation coefficient, R = 0.9995). The method gives acceptable recoveries: R = 102% for liquid soap. Relative standard deviation is 1.14%. These results demonstrate that the system can determine the concentration of CA in PC products. This automated CA analysis frees up analysts from routine laboratory work for more technically difficult projects. The robot is capable of managing 36 samples per day, which is more than three times higher capacity than the manual procedure. © 2000 John Wiley & Sons, Inc. Lab Robotics and Automation 12:282–285, 2000