First Time Determination of Important Catalyst Sodium Methoxide Used in Biodiesel by Colorimetric Method

Abstract

A simple and selective spectrophotometric method has been developed for the first time for the determination of sodium methoxide in methanol solution in the presence of sodium hydroxide. The developed method involves the formation of a pink species by the reaction between sodium methoxide and α-santonin. The pink compound formed shows absorbance maximum at 513 nm. N, N-Dimethylformamide and methanol were used as solvents, and the reaction was performed at different temperatures and 25 °C was selected for further experiments. The pink compound formed was dried and then was studied using FTIR and mass spectrometry. The calibration curve was constructed from 0.10 to 0.30% (m/v) sodium methoxide in methanol, and the standard deviation is 0.010%. Similarly, the relative standard deviations of 28%, 26%, and 24% solutions of sodium methoxide were obtained in the range of 0.4 to 1.9%. The correlation coefficient of the analytical curve r = 0.9997; the limit of detection, LOD, is ca. 1.1 × 10 % w/w; and the limit of quantification, LOQ, is ca. 3.2 × 10 % w/w. The results of analysis were validated statistically.

A convenient and practical synthesis of β-diketones bearing linear perfluorinated alkyl groups and a 2-thienyl moiety

“…A few analytical methods were developed to measure the concentrations of NaOR and NaOH. They include the potentiometric titration with modified Karl Fisher’s reagents [26], spectrophotometric determination of NaOR with α-santonin [27], thermometric determination of alkoxides [28] and some other special techniques. Unfortunately, these methods are too laborious for a common synthetic laboratory.…”

Otimização Da Reação De Transesterificação Metílica Do Óleo De Soja Catalisada Por Silicato De Sódio Derivado Das Cinzas De Casca De Arroz

“…O segundo, com o emprego de excesso do álcool, para forçar o equilíbrio no sentido dos produtos (KNOTHE;. O catalisador mais empregado é o metóxido de sódio.O reagente é comercializado na forma de solução 25 a 30 % em metanol apresentando algumas desvantagens, como alto custo, dificuldades de armazenamento e riscos com o manuseio(KHAN et al, 2018). O metóxido de sódio é um catalisador homogêneo.…”