title: Spectrophotometric determination of trace carbaryl in water and grain samples by inhibition of the rhodamine-B oxidation.
abstract: A novel, sensitive, selective and simple kinetic spectrophotometric method has been developed for determination of trace levels of carbaryl based on its inhibitory effect on the oxidation of rhodamine-B by chlorine and bromine released from reaction of potassium bromate with hydrochloric acid in micellar medium. A linear relationship was observed between the inhibitory effect and the concentration of the compound. The absorbance was monitored at the maximum wavelength of 555 nm. The effect of different parameters such as pH, temperature and concentration of rhodamine-B, potassium bromate and surfactant on the reaction were investigated and optimum conditions were established. Under the selected experimental conditions, carbaryl was determined in the range of 0.04-0.4 μg mL(-1). Sandell's sensitivity and molar absorptivity were found to be 0.00055 μg cm(-2) and 3.658×10(5) L mol(-1) cm(-1) respectively. The proposed method was applied satisfactorily for the determination of carbaryl in water and different grain samples. The results were compared with those obtained by reference method and were found to be in agreement.
authors.affiliation: Dept. of Chemistry, Govt. V.Y.T. PG Autonomous College, Durg, Chhattisgarh 491001, India.
authors.forename: Nirja
authors.initials: N
authors.lastname: Gupta
authors.affiliation: Dept. of Chemistry, Govt. V.Y.T. PG Autonomous College, Durg, Chhattisgarh 491001, India.
authors.forename: Ajai Kumar
authors.initials: AK
authors.lastname: Pillai
authors.affiliation: Shri Shankaracharya Engineering College, Junwani, Bhilai, Chhattisgarh 490001, India.
authors.forename: Prachi
authors.initials: P
authors.lastname: Parmar
mesh_terms: D001959:Bromates / Q000737:chemistry; D002138:Calibration; D012721:Carbaryl / Q000032:analysis*; D004396:Coloring Agents / Q000737:chemistry; D002523:Edible Grain / Q000737:chemistry*; D006851:Hydrochloric Acid / Q000737:chemistry; D007700:Kinetics; D008823:Micelles; D010084:Oxidation-Reduction; D015203:Reproducibility of Results; D012235:Rhodamines / Q000737:chemistry*; D013053:Spectrophotometry / Q000379:methods*; D013696:Temperature; D014867:Water / Q000737:chemistry*
chemical_list: D001959:Bromates; D004396:Coloring Agents; D008823:Micelles; D012235:Rhodamines; C019536:potassium bromate; D014867:Water; C029773:rhodamine B; D006851:Hydrochloric Acid; D012721:Carbaryl
keywords: Carbaryl; Micellar medium; Potassium bromate; Rhodamine-B; Spectrophotometry