Spectroscopic profiles and solubilisation kinetics of methylene blue dye in unwholesome liquid detergents

Abstract

The spectroscopic profiles and solubilisation kinetics of Methylene blue in unwholesome liquid detergents was carried out using mechanical shaker and BK-UV 1900 PC Scanning Spectrophotometer. Sodium dodecyl benzene sulphonate (SDBS) served as control (1), while the registered Potential fabric wash (PFW) served as control (2). Test fabric wash (TFW), test car wash (TCW), test dish water (TDW) and test toilet wash (TTW) were used as unwholesome liquid detergents. Pieces of white cotton fabrics were stained with known concentration of MB and solubilised with known concentrations of the liquid detergents. The effects of dye dosage, detergent dosage, contact time, detergency, solubilisation kinetics and percent weight lost were studied. Data from the research showed that the extent of solubilisation of dyes increased with increasing initial MB and detergents concentrations. The solubilisation kinetics was determined using pseudo first and second order kinetic models. The percent removal of dye from white cotton fabrics using individual detergents at equilibrium times gave the following result in that order: SDBS(99.60) > PFW(67.13) > TFW(62.30) > TDW(45.52) > TTW(37.93 ) >TCW(21.38). Kinetic studies of the detergents revealed that 2^nd order kinetics was relatively more effective for describing the whole detergents solubilisation process. Percent fabric lost showed that all unwholesome liquid detergents have high percent loss ranging between 1.36-2.97 as compared with the registered PFW(0.49) detergent. The present work aims to examine the solubilisation of methylene blue dye in registered and unwholesome liquid detergents concerning detergents concentrations, dye/detergent dosage, contact time, detergency, weight loss and solubilisation kinetics of dye in known concentrations and their (registered and unwholesome liquid detergents) solubilisation efficiencies compared. The results showed that NAFDAC registered (PFW) liquid detergent showed better percent active ingredient, concentration, detergency and washing efficiency than all the unwholesome liquid detergents.