Application of the Multivariate Calibration-Spectrophotometric Method to Determination of Linear Alkyl Benzene Sulfonate (LABS) in Liquid Detergent

Mahmoud Reza Sohrabi, Atena Adnani and Arezoo Hassan Nouri

Department of Chemistry, Islamic Azad University, North Tehran Branch, P.O.Box 19585 - 936, Tehran (Iran)

The aim of this study was a spectrophotometrical determination of Linear Alkyl Benzene Sulfonate (LABS) as an anionic surfactant in liquid detergent by multivariate calibration. One of the powerful tools in multivariate calibration is the partial least squares method (PLS), which was used for analysis of LABS in the 0.01-0.025 (g/ml) concentration range. Absorbance data of the calibration standards were taken between 200-600 nm with a UV-vis spectrometer. These spectral data and concentrations were used as inputs and outputs of the model, respectively. In the other step, first order derivative spectra were considered as inputs of the model and the parameters of the model were tested. For achieving the best parameters of the model in each step errors were calculated as RMSECV values. Relative errors of less than 3% for the zero and first derivative spectral data sets were obtained.

Partial Least Squares (PLS); Linear alkyl benzene sulfonate; spectrophotometry; detergent