Simple flow system with in-line gas-diffusion unit for determination of ethanol employing hypsochromic shift of visible absorbance band of methyl orange

This study presents a simple flow-based system for the determination of the preservative agent sulfite in food and beverages. The standard method of conversion of sulfite ions into SO2 gas by acidification is employed to separate the sulfite from sample matrices. The sample is aspirated into a donor stream of sulfuric acid. A membrane gas–liquid separation unit, also called a ‘gas-diffusion (GD)’ unit, incorporating a polytetrafluoroethylene (PTFE) hydrophobic membrane allows the generated gas to diffuse into a stream of deionized water in the acceptor line. The dissolution of the SO2 gas leads to a change in the conductivity of water which is monitored by an in-line capacitively coupled contactless conductivity detector (C4D). The conductivity change is proportional to the concentration of sulfite in the sample. In this work, both clear (wine) and turbid (fruit juice and extracts of dried fruit) were selected to demonstrate the versatility of the developed method. The method can tolerate turbidity up to 60 Nephelometric Turbidity Units (NTUs). The linear range is 5–25 mg L−1 SO32− with precision <2% RSD. The flow system employs a peristaltic pump for propelling all liquid lines. Quantitative results of sulfite were statistically comparable to those obtained from iodimetric titration for the wine samples.

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Simple flow system for the rapid pre-concentration and potentiometric determination of fluoride using a micro-column and a wall-jet electrode

The Analyst ◽

10.1039/an9891401267 ◽

1989 ◽

Vol 114 (10) ◽

pp. 1267 ◽

Cited By ~ 8

Author(s):

Yoshito Okabayashi ◽

Michiyo Hikawa ◽

Terumichi Nakagawa ◽

Hisashi Tanaka ◽

Masahiko Chikuma

Keyword(s):

Flow System ◽

Potentiometric Determination ◽

Wall Jet ◽

Simple Flow

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Simple Design Flow Analysis System for Determination of Iron by Spectrophotometric method

Jurnal ILMU DASAR ◽

10.19184/jid.v16i2.1519 ◽

2016 ◽

Vol 16 (2) ◽

pp. 89

Author(s):

Wiwin Setiani ◽

Tri Mulyono ◽

Asnawati Asnawati

Keyword(s):

Flow Rate ◽

Spectrophotometric Method ◽

Systems Analysis ◽

System Analysis ◽

Flow System ◽

Analysis Method ◽

Batch Method ◽

Flow Systems ◽

Simple Flow

The purpose of this research is to make a series of analyzes using a flow system with a bottle Marriote as pump and spectrophotometric method for determining the content of iron in water samples. Determination of iron by this method used 1,10-fenantrolin complexing or 2,2-bipyridyl. In this method, Fe3+ is reduced to Fe2+ prior complexed with iron to form a specific color and then flowed it through a marriote bottle next to the spectrophotometer detector. The average flow rate of the liquid in the bottle Marriote amounted to 0.037 mL / sec. Limit detection obtained in the batch is 0.00017 ppm and 0.00023 ppm in simple flow systems analysis methods. Sensitivity obtained in the batch method is 0.027 and the simple flow system analysis method is 0.035. Flow rate precision values are expressed Marriote bottle with Kv values <5%. Values accuracy expreced percenting of recovery was 99% in the batch method, whereas the simple flow system analysis method was 98.5%. Results of t-test analysts suggest that iron determination using flow systems analysis (FIA) with the replacement pump bottle Marriote not differ significantly from the results obtained with the batch system. Keywords: batch method, bottle Marriote, Flow Injection Analysis, spectrofotometry

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