| Abstract: | The mechanization of attenuated total reflectance measurements (ATR) in Fourier Transform Infrared spectrometry (FTIR) through the use of multicommutation has been evaluated in order to reduce the sample consumption and waste generation also avoiding risks of cells breaking. A new multicommutation ATR-FTIR procedure has been proposed for the determination of sodium alpha-olefin sulfonate (AOS) in liquid detergent formulations. The main advantages of this method are the low consumption of sample (96 ml per 100 determinations) and the analytical throughput (23 h−1 versus 15 h−1 for the manual mode). Results obtained for reference samples containing 7.52% to 9.52% (w/w) of AOS are in the 0.5% (w/w) error range, with a mean precision of 0.3% RSD. Recovery studies evidence the accuracy of the method, with average values around 100%. It was evaluated the possibilities of ATR-FTIR analysis of different types of liquid samples like beer, orange juice, milk and olive oil, showing the great versatility and applications of this approach to improve sample introduction and cell cleaning. |
