scholarly journals An Environmentally Friendly Flow Injection-Gas Diffusion System Using Roselle (Hibiscus sabdariffa L.) Extract as Natural Reagent for the Photometric Determination of Sulfite in Wines

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Preeyaporn Reanpang ◽  
Teerarat Pun-uam ◽  
Jaroon Jakmunee ◽  
Supada Khonyoung
Keyword(s):  
Flow Injection ◽  
Environmentally Friendly ◽  
Photometric Determination ◽  
Gas Diffusion ◽  
Hibiscus Sabdariffa ◽  
Permeable Membrane ◽  
Relative Standard ◽  
Color Fading ◽  
Acceptor Solution

In this work, a green and simpler method for photometric determination of sulfite based on a flow injection-gas diffusion (FI-GD) system using a natural reagent extracted from roselle (Hibiscus sabdariffa L.) was proposed. Despite the fact that the employed reaction is not selective to sulfite, its sensitivity is high, and the selectivity can be improved by coupling a GD unit to the FI system. The method involves monitoring a decrease in absorbance of the reagent solution that is used as an acceptor solution. When a standard solution or sample solution was injected into an acidic donor stream, the liberated sulfur dioxide diffuses through a gas-permeable membrane of the GD unit into the acceptor solution, causing color fading of the reagent. A linear analytical curve in the range of 5–100 mg L−1 was obtained with a detection limit of 2 mg·L−1. Relative standard deviations of 0.9%, 0.6%, and 0.6% were obtained for the determination of 30, 70, and 100 mg·L−1 SO32- (n = 11). The developed method was applied to wine samples, giving results that agreed with those obtained with the Ripper titrimetric method. The proposed method offers advantages of simplicity, cost-effectiveness, and being environmentally friendly such as reduced chemical consumption and less waste generation.

Gas Diffusion-Flow Injection Determination of Free and Total Sulfur Dioxide in Wines by Conductometry

1998 ◽  
Vol 63 (6) ◽  
pp. 770-782 ◽  
Author(s):  
Petr Kubáň ◽  
Pavel Janoš ◽  
Vlastimil Kubáň
Keyword(s):  
Sulfuric Acid ◽  
Detection Limit ◽  
Sulfur Dioxide ◽  
Flow Injection ◽  
Gas Diffusion ◽  
Total Sulfur ◽  
Diffusion Flow ◽  
Pvdf Membrane ◽  
Relative Standard

Sensitive flow injection analysis methods for the determination of free and total sulfur dioxide in wines are presented. The bound S(IV) was liberated by alkaline hydrolysis with 4 mol/l NaOH. All forms of S(IV) were liberated from the sample zone by sulfuric acid and subsequently transported through a microporous PVDF membrane. The penetrated gases were collected in water for preselected period and determined by conductometry with detection limit 1 mg/l and relative standard deviations 0.8 and 0.6% at 10 and 150 mg/l (n = 10) for free and total S(IV), respectively. The results are comparable with those obtained by standard titrimetric procedures with visual (Czech State Standard) and/or potentiometric indication.

scholarly journals Potentiometric determination of total nitrogen in soils by flow injection analysis with a gas-diffusion unit

Soil Research ◽  
1996 ◽  
Vol 34 (4) ◽  
pp. 503 ◽  
Author(s):  
AMR Ferreira ◽  
J Lima ◽  
A Rangel
Keyword(s):  
Total Nitrogen ◽  
Flow Injection ◽  
Flow Injection Analysis ◽  
Sampling Rate ◽  
Gas Diffusion ◽  
Ammonium Ion ◽  
Selective Electrode ◽  
Buffer Solution ◽  
Permeable Membrane

A flow injection analysis (FIA) system incorporating a gas-diffusion unit and a potentiometric detector was developed for the determination of total nitrogen in soil digests. The solutions obtained from the Kjeldahl digestion of the soil samples were injected in the FIA system where ammonium was converted into ammonia. This gas diffused through a gas-permeable membrane to a buffer acceptor stream, allowing the separation of the gas from the rest of the sample. Once in contact with the buffer solution, ammonia was reconverted into ammonium and finally led to a tubular ammonium ion-selective electrode constructed for this purpose. The potentiometric detector is a PVC tubular selective electrode without inner reference solution, and with the sensor system composed of monactin in Tris (2-ethylhexyl) phosphate. Good agreement was obtained between the results provided with the developed FIA system and those from the classical Kjeldahl distillation/titration step, with relative deviations between the 2 methods always < 5%. A sampling rate of 80 determinations/h was achieved with good reproducibility for consecutive injections of soil digests (coefficients of variation < 3%).

Flow-injection photometric determination of trace copper in natural waters

2000 ◽  
Vol 55 (1) ◽  
pp. 34-36 ◽  
Author(s):  
L. N. Moskvin ◽  
G. L. Grigor’ev ◽  
A. L. Moskvin ◽  
O. A. Pisareva ◽  
N. M. Yakimova ◽  
...  
Keyword(s):  
Flow Injection ◽  
Natural Waters ◽  
Photometric Determination

scholarly journals Automation of flow injection gas diffusion-ion chromatography for the nanomolar determination of methylamines and ammonia in seawater and atmospheric samples

1995 ◽  
Vol 17 (6) ◽  
pp. 205-212 ◽  
Author(s):  
Stuart W. Gibb ◽  
John W. Wood ◽  
R. Fauzi ◽  
C. Mantoura
Keyword(s):  
Ion Chromatography ◽  
Flow Injection ◽  
Aqueous Media ◽  
Control Unit ◽  
Gas Diffusion ◽  
Aqueous Sample ◽  
In Series ◽  
And Performance ◽  
Improved Design

The automation and improved design and performance of Flow Injection Gas Diffusion-Ion Chromatography (FIGD-IC), a novel technique for the simultaneous analysis of trace ammonia (NH3) and methylamines (MAs) in aqueous media, is presented. Automated Flow Injection Gas Diffusion (FIGD) promotes the selective transmembrane diffusion of MAs and NH3from aqueous sample under strongly alkaline (pH > 12, NaOH), chelated (EDTA) conditions into a recycled acidic acceptor stream. The acceptor is then injected onto an ion chromatograph where NH3and the MAs are fully resolved as their cations and detected conductimetrically. A versatile PC interfaced control unit and data capture unit (DCU) are employed in series to direct the selonoid valve switching sequence, IC operation and collection of data. Automation, together with other modifications improved both linearily (R2> 0.99 MAs 0-100 nM, NH30-1000 nM) and precision (<8%) of FIGD-IC at nanomolar concentrations, compared with the manual procedure. The system was successfully applied to the determination of MAs and NH3in seawater and in trapped particulate and gaseous atmospheric samples during an oceanographic research cruise.

scholarly journals Spectrophotometric flow injection procedure to indirect determination of paracetamol in pharmaceutical formulations using o-tolidine as reagent

2018 ◽  
Vol 33 (2) ◽  
pp. 47
Author(s):  
Orlando Fatibello-Filho ◽  
Heberth Juliano Vieira
Keyword(s):  
Standard Deviation ◽  
Detection Limit ◽  
Flow Injection ◽  
Pharmaceutical Formulations ◽  
Injection Method ◽  
Indirect Determination ◽  
Analytical Curve ◽  
Relative Standard ◽  
Injection Procedure

A spectrophotometric flow injection method for the determination of paracetamol in pharmaceutical formulations is proposed. The procedure was based on the oxidation of paracetamol by sodium hypochloride and the determination of the excess of this oxidant using o-tolidine dichloride as chromogenic reagent at 430 nm. The analytical curve was linear in the paracetamol concentration range from 8.50 x 10-6 to 2.51 x 10-4 mol L-1 with a detection limit of 5.0 x 10-6 mol L-1. The relative standard deviation was smaller than 1.2% for 1.20 x 10-4 mol L-1 paracetamol solution (n = 10). The results obtained for paracetamol in pharmaceutical formulations using the proposed flow injection method and those obtained using a USP Pharmacopoeia method are in agreement at the 95% confidence level.

Rapid Determination of Sulfite by Flow Injection Analysis Based on Fuchsin′s Addition

2013 ◽  
Vol 295-298 ◽  
pp. 950-953 ◽  
Author(s):  
Dong Yuan ◽  
Da You Fu ◽  
Wen Yuan Tan
Keyword(s):  
Flow Injection ◽  
Addition Reaction ◽  
Rapid Determination ◽  
Sampling Rate ◽  
Optimum Conditions ◽  
Linear Calibration ◽  
Relative Standard ◽  
Replicate Measurements ◽  
Good Agreement

A rapid spectrophotometric method for flow injection determination of sulfite in tan wastewater is described. The proposed method was based on the addition reaction of sulfite with fuchsin in Na2B4O7-NaOH medium. The optimum conditions allow a linear calibration range of 0.01-1.20 μg ml-1 SO32-. The detection limit is 0.0023μg ml-1 (S/N=3), and the relative standard deviation for night replicate measurements is 1.1% for 0.5μg ml-1 of sulfite. The sampling rate is 60 samples h-1. The procedure has been applied to the determination of sulfite in tan wastewater. The results were in good agreement with those obtained by pararosaniline method.

scholarly journals Determination of Sulfate in Natural and Residual Waters by Turbidimetric Flow-Injection Analysis

2001 ◽  
Vol 84 (1) ◽  
pp. 59-64 ◽  
Author(s):  
Inês P A Morais ◽  
António O S S Rangel ◽  
M Renata S Souto
Keyword(s):  
Detection Limit ◽  
Flow Injection ◽  
Reference Method ◽  
Previous Treatment ◽  
Barium Chloride ◽  
Sulfate Solution ◽  
Injection System ◽  
Residual Water ◽  
Relative Standard

Abstract A turbidimetric flow-injection system was developed for the determination of sulfate in natural and residual water samples, with no previous treatment, using spectrophotometric detection. The precipitating agent, 7.0% (w/v) barium chloride solution prepared in 0.10% (w/v) polyvinyl alcohol, was added by using the merging-zones approach. A 100 mg/L sulfate solution in 0.07M nitric acid was mixed with the sample before it entered the injection loop to improve the detection limit, provide in-line pH adjustment, and prevent the interference of some anionic species. The relative standard deviations of the results were between 1.4 and 3.0% and were in agreement with results obtained by the reference method. Samples within a linear concentration range of 10–120 mg SO42−/L can be analyzed at a rate of 40/h. The detection limit is 5 mg SO42−/L.

Automated multiple flow-injection analysis in clinical chemistry: determination of albumin with bromcresol green.

1980 ◽  
Vol 26 (2) ◽  
pp. 331-334 ◽  
Author(s):  
B W Renoe ◽  
K K Stewart ◽  
G R Beecher ◽  
M R Wills ◽  
J Savory
Keyword(s):  
Standard Deviation ◽  
Relative Standard Deviation ◽  
Flow Injection ◽  
Flow Injection Analysis ◽  
Clinical Chemistry ◽  
Analytical Results ◽  
Relative Standard ◽  
Clinical Chemical ◽  
Bromcresol Green

Abstract We describe an adaptation of automated multiple flow-injection analysis instrumentation to an analysis for albumin in serum. The bromcresol green reaction was used to test the utility of the system. The approach yielded albumin results with excellent sensitivity, no measurable carryover, a relative standard deviation of less than 1%, good correlations with published procedures, and no measurable interferences. The simplicity and flexibility of the instrumentation and its performance integrity, as indicated by the analytical results, make this a viable clinical chemical tool.

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