Publication: Simple flow system with in-line gas-diffusion unit for determination of ethanol employing hypsochromic shift of visible absorbance band of methyl orange
0
0
Issued Date
2020
Resource Type
File Type
application/pdf
ISSN
399140
Other identifier(s)
2-s2.0-85070545728
Rights Holder(s)
Scopus
Bibliographic Citation
Talanta. Vol 206, (2020)
Suggested Citation
Ratanawimarnwong N., Sinpun M., Chankaw P., Choengchan N., Nacapricha D. Simple flow system with in-line gas-diffusion unit for determination of ethanol employing hypsochromic shift of visible absorbance band of methyl orange. Talanta. Vol 206, (2020). doi:10.1016/j.talanta.2019.120234 Retrieved from: https://hdl.handle.net/20.500.14740/4856
Abstract
The effect of solvent composition on the uv–visible spectrum of methyl orange was investigated for application to the quantitative determination of ethanol. At fixed pH, there was a hypsochromic shift of the absorbance band of methyl orange with increasing ethanol concentration. Using acetate buffer at pH 3.40 the change of absorbance at 530 nm of a solution of methyl orange containing known concentrations of standard ethanol was measured to provide a calibration curve. In order to apply this method to the analysis of alcoholic samples, such as distilled spirits, blended spirits and liquid herbal medicines, a simple gas-diffusion unit coupled with flow system was employed to separate the ethanol from sample matrices. Using the gas diffusion-flow system and employing an evaporation time of 2 min, a linear calibration range of 5–45% (v/v) ethanol was achieved ((ΔA = (0.0078 ± 0.0002)x(ethanol, %(v/v)) + (0.040 ± 0.005)), r2 = 0.998). The limit of detection (3σ blank/slope) was 2.23% (v/v). The developed gas diffusion-flow system was applied to the analysis of colorless distilled spirits, yellow blended spirits and dark brown herbal medicines that are available in the local markets of Bangkok, Thailand. Validation of the method was carried out by comparing the results with analysis using gas chromatography. There was no statistically significant difference at the 95% confidence level for all alcoholic samples analyzed. © 2019 Elsevier B.V.
Subject(s)
Azo dyes
Calibration
Citrus fruits
Diffusion in gases
Ethanol
Gas chromatography
Gases
Medicine
Plant extracts
Calibration curves
Effect of solvents
Ethanol concentrations
Gas diffusion
Hypsochromic shifts
Methyl Orange
Quantitative determinations
Statistically significant difference
Organic solvents
Calibration
Citrus fruits
Diffusion in gases
Ethanol
Gas chromatography
Gases
Medicine
Plant extracts
Calibration curves
Effect of solvents
Ethanol concentrations
Gas diffusion
Hypsochromic shifts
Methyl Orange
Quantitative determinations
Statistically significant difference
Organic solvents