Study of methanol catalyzed reaction between sodium 1,2-naphthoquine-4-sulfonate and hydroxyl ion and its application in the determination of methanol.
A novel and simple spectrophotometric method for the direct determination of methanol with 1,2-naphthoquinone-4-sulfonate (NQS) is developed in this paper. It is based on the fact that methanol can catalyze the reaction between 1,2-naphthoquinone-4-sulfonate and hydroxyl ion to form 2-hydroxy-1,4-naphthoquinone in buffer solution of pH 13.00. Beer's law is obeyed in a range of 0.26-15.8 mg/ml at the maximal absorption wavelength of 454 nm. The equation of linear regression is A = 0.01998 + 0.05944C (mg/ml), with a linear regression correlation coefficient of 0.9977. The detection limit is 0.25mg/ml (3sigma/k), while R.S.D. is 2.0% and the recovery rate is in a range of 96.5-103%. The detailed mechanism for the formation of the products is proposed and discussed.
Li
Quanmin
Q
College of Chemistry and Environmental Science, Henan Normal University, Henan Key Laboratory for Environmental Pollution Control, Xinxiang, Henan 453007, PR China. mercury6068@hotmail.com
Zhang
Huanhuan
H
D002021:Buffers; D002384:Catalysis; D006863:Hydrogen-Ion Concentration; D006878:Hydroxides; D007477:Ions; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D000432:Methanol / Q000032:analysis* / Q000737:chemistry; D008956:Models, Chemical; D009285:Naphthoquinones / Q000737:chemistry*; D012044:Regression Analysis; D013053:Spectrophotometry / Q000379:methods; D013055:Spectrophotometry, Infrared / Q000379:methods; D013451:Sulfonic Acids / Q000032:analysis*; D013696:Temperature
D002021:Buffers; D006878:Hydroxides; D007477:Ions; D009285:Naphthoquinones; D013451:Sulfonic Acids; C533173:sodium 1,2-naphthoquine-4-sulfonate; C031356:hydroxide ion; D000432:Methanol