Determination Of Sulfur Dioxide Research Articles

Validation of a fast automated photometric method for the analysis of sulfur dioxide in wines

In this work a simple and rapid automated analytical method for the determination of sulfur dioxide in wines by employing a sequential automatic analyser was validated. The methodology is based on the reaction of sulfur dioxide with 5,5′-dithiobis-(2-nitrobenzoic acid) in an alkaline medium followed by photometric detection. The linearity of the calibration curve was excellent (R2 = 1.000) and the LOQ (2.00 mg L−1) was well suited for the monitoring of regulatory limits. The accuracy and precision were evaluated with reference materials, providing highly successful results (RSD% < 3.8 for precision and R2 = 0.99 of correlation between the obtained and declared values). The method was applied to the analysis of commercial samples of wines ensuring compliance with legislation. The results found were compared to those obtained with the spectrophotometric method recommended for beers, implemented in a flow system, showing that there are no statistical differences between them (α ≤ 0.05). When compared with conventional methods, the proposed methodology showed to be fast, with minimum handling of the sample and small sample and reagents volume requirement, which together with a minimum maintenance, involves a considerable reduction in laboratory costs.

Headspace single drop microextraction based visual colorimetry for highly sensitive, selective and matrix interference-resistant determination of sulfur dioxide in food samples.

Excessive intake of SO2, a widely-used food additive, is able to cause respiratory, cardiovascular and neurological disease. For effectively monitoring SO2 level, we have developed a headspace single drop microextraction based visual colorimetry for highly sensitive and selective sensing of SO2 with TMB (3,3',5,5'-tetramethylbenzidine) as a classic chromogenic reagent. A combination of single drop and headspace microextraction integrated merits of high extraction efficiency, low consumption of reagents and excellent matrix interference-resistant ability. The colorimetric principle was based on oxidation of TMB, and SO2 could compete with TMB to preferentially react with ·OH, resulting in the fading of color blue that could be easily read out by naked eye. LOD was calculated to be 0.53μM and 5μM by UV-vis and naked eye, respectively. The method was successfully utilized to analysis of food samples, and the experimental device was miniaturized and easy to construct, thus showing a promising potential in field analysis.

Determination of sulfur dioxide in food by liquid chromatography with pre-column derivatization

A derivatization method to determine the sulfur dioxide content in food was established. Under weakly acidic conditions, fluorescent 2H-isoindole-1-sulfonate was synthesized by a derivatization reaction using an ammonium salt and o-phthalaldehyde as the derivative reagent. High-performance liquid chromatography and a high-sensitivity fluorescence detector were used for detection, in which a fluorescence spectrophotometer was used to determine the maximum excitation wavelength and emission wavelength of2H-isoindole-1-sulfonate. When the excitation wavelength was 323 nm and the emission wavelength was 386 nm, the linear range of fluorescence intensity of the sulfur dioxide standard was 0–10 μg/mL, and the correlation coefficient was 0.996. The standard recoveries of six kinds of food were approximately 80–110%, the RSD was 0.2–2.89, the detection limit was 0.2 mg/kg, and the quantitative limit was 0.7 mg/kg. The results of this research indicate that this method is suitable for determining sulfur dioxide in food.

The method of determination for sulfur dioxide in the air of workplace by ion chromatography without derivatization

Objective: To establish a method for the determination of sulfur dioxide (SO2) in the air of workplace, which including the process of collection by absorption in triethanolamine aqueous solution and the process of analysis and detection by iron chromatography directly without derivatization. Methods: SO2 in the air of workplace was collected at a flow rate of 0.5 L/min for 15 min through 10 ml of 3% triethanolamine aqueous solution filled in a porous glass plate absorption tube. The absorption solution passed through IonPacAS14A analytical column (4 mm×250 mm) and IonPacAG14 protective column (4 mm×50 mm) at a column temperature of 30 ℃, using Na2CO3 (3.0 mmol/L) -NaHCO3 (1.0 mmol/L) as mobile phase with the flow rate of 1.2 ml/min, and was detected by conductivity detector. Results: It showed that SO2 in triethanolamine solution could be stored for at least 7 d at room temperature (25 ℃) and 37 ℃. There was a linear relationship within the determination range of 0-8.00 μg/ml, the linear correlation coefficient was 0.9999. The sampling absorption efficiency was 98.1%-100.0%, the detection limit of the method was 0.018 μg/ml, the minimum detection concentration was 0.024 mg/m3 (based on V0=7.5 L) . The recovery rate was 99.22%-101.69%, the intra batch precision was 0.41%-1.34%, and the inter batch precision was 0.73%-1.77%. Conclusion: The method has the advantages of simple operation, high sensitivity and good accuracy. It can prevent SO2 from being oxidized and realize the direct detection of SO2 in the air of workplace without derivation.

Determination of Air Pollutant Concentrations in Plant Species in Relation to Pollution Sources

Air quality has been a major health issue in urban areas in recent decades. Human activities release a large number of pollutants into the atmosphere which has a direct impact on plant health and leads to ecosystem degradation. The objective of this study is to contribute to a better evaluation of the impact of the air quality of the city of Togo on biological resources. The determination of pollutants was done on samples of plant species with a strong link with the source of pollution. The determination of Sulfur dioxide (SO2) was done by the ripper method. The determination of carbon and estimation of CO2 and CO by the colorimetric method. The determination of nitrogen was done by the Kjeldhal method. The results showed that at the industrial level the amount of CO2 in Alternanthera repens is high with a value of 53.3911 mg/ml. On the other hand, the quantity of CO in Senna occidentalis is 44.3619 mg/ml. In Pithecellobium dulce, the quantity of SO2 and NO2 are evaluated respectively to 0.1588 mg/ml and 0.3696 mg/ml. Regarding to the dumps, the quantity of CO2 in Newbouldia laevis is very high with a value of 65.8508 mg/ml. On the other hand the amount of CO in Senna occidentalis is 51.6106 mg/ml. The quantity of SO2 in Newbouldia laevis is 0.2101 mg/ml and NO2 in Ocimum canum is 0.2744 mg/ml. At the level of roads, the quantities of CO2 and CO in Eragrostis tenella are very high with values respectively equal to 74.4092 mg/ml and 62.2654 mg/ml. On the other hand, the amount of NO2 in Amaranthus sp is 0.2304 mg/ml and that of SO2 in Eragrostis Tenella is 0.1691 mg/ml. The use of a plant bioindicator sensitive to pollutants, allowed concluding that the air of the city of Lome is polluted. The concentration of carbon dioxide and carbon monoxide is much more evident in return when the health of plant species is threatened.

Determination of Sulfur Dioxide (SO2) Safe Duration in Residential Population Around the Fertilizer Industry X in Indonesia

People who have lived more than 22 years in settlements around the fertilizer industry X are at risk of being exposed to SO2 from the increase in exhaust emissions produced by the boilers and power generation equipment in the fertilizer industry. The purpose of this study was to determine the Risk Quotient (RQ) due to exposure to SO2 and to measure the duration of exposure to SO2 that is safe in the residential area around the fertilizer industry X. This research is a quantitative study with an environmental health risk analysis method, with a sample size of 297 adult population respondents in residential areas around the center of SO2 emissions in the fertilizer industry X area. Data analysis was done using manual data calculations to determine the intake of SO2 (non carcinogenic), risk level or risk quotient (RQ), and safe duration (Dt safe) exposure to SO2 in the population around the fertilizer industry X. The results showed that the average non-carcinogenic intake of SO2 in settlements around the fertilizer industry X was at 0.057427415mg/kg/day. While the average risk quotient is 1.788347507 (RQ> 1), from a total of 297 respondents as many as 197 respondents with RQ> 1 and 100 respondents with RQ 50 of the population in settlements around the fertilizer industry X have health risks resulting from exposure to SO2. The average safe duration of exposure to SO2 in the population in settlements around the fertilizer industry X is 23.47 years, depending on the food intake and body condition of the respondents. The recommendation that can be given is to increase the weight of respondents and the right diet pattern by consuming nutritional intake that can detoxify the main toxin to reduce sulfur dioxide levels in the body, one example is the provision of vitamins E and C which can reduce oxidative effects such as lipid peroxidation and membrane damage in erythrocytes due to exposure to sulfur dioxide2. Besides that, a related stakeholder policy is needed to periodically measure SO2 concentrations in community residential areas around the fertilizer industry X, so that the air quality of people exposed to SO2 can be monitored and is still within safe limits. The company holds a CSR program involving the surrounding community by conducting routine health checks, greening programs around the fertilizer industrial area6. © 2019, Indian Journal of Public Health Research and Development. All rights reserved.

Total Sulfur Dioxide Determination in Red Wine by Suppressed Ion Chromatography with In-Sample Oxidation and SPE

Suppressed ion chromatography (IC) based on in-sample oxidation and SPE is described for total sulfur dioxide determination in red wines. In this method, sulfur dioxide was converted to stable sulfate ion through a simple H2O2 oxidation step and then the impurities were removed with C-18 micro-column SPE pretreatment. Finally, the sulfate was determined by suppressed ion chromatography coupled with conductivity detection and the content of total sulfur dioxide could be obtained through sulfate content by blank deduction method. By using a mixture of NaHCO3 and Na2CO3 as mobile phase, the analysis of one sample with nine anions could be completed within 25 min. For sulfate detection, a linear calibration curve with correlation coefficient of 0.9993 was obtained from the peak area with low detection limit (0.45 mg L−1, 3σ) and excellent repeatability (RSD = 1.12%, n = 6). This method was applied to sulfur dioxide determination in real wine samples and compared with conventional iodometry.

Effects of Nitrogen Dioxide and Carbon Monoxide on the Determination of Sulfur Dioxide by Flue Gas Analyzer

Reference materials of SO2, NO2 and CO were used to study the effects of different concentrations of NO2 and CO on the determination value of SO2 by flue gas analyzer with electrochemical sensors and UV differential optical absorption spectroscopy (DOAS). Results showed that SO2 was affected more greatly by NO2 than CO using the method of electrochemical sensors. The electrolytic reaction of NO2 was the primary factor causing the lowerconcentration of SO2. SO2 with the concentration of 0–300 mg/m3 was affected greatly by NO2, and the determination value was unreliable. The determination error of SO2, with the concentration higher than 1500 mg/m3, was about 2%, and the test value was more accurate. The method of UV DOAS could improve the determination reliability of concentration of SO2 greatly when NO2 coexisted.

Detection of Sulfite Content in Agricultural Products Logistics Technology Research—Taking an Example of Mushroom

In today’s real life, from the perspective of the logistics quality of agricultural products, there are many problems are paid attention by social people, such as mushroom. Mushroom products in China’s exports have repeatedly been reported because of containing more sulfur dioxide in recent years. Also the dried mushroom exports were notified by nine times. Mushroom in the life is one of the people’s favorite foods, so food healthy problem is to let the consumer concern it. This article explores a new method by pararosaniline hydrochloric spectrophotometry for determination of sulfur dioxide in mushroom, in the instrument detection and method research. This experiment uses the colorimetric method that is in charge of the UV spectrophotometer instrument. Finally this article puts forward the feasibility of this method. In the determination of mushrooms, laboratory reagents are used with non-toxic mercury. It reaches the national standard and it has practical feasibility.

Simple spectrophotometry method for the determination of sulfur dioxide in an alcohol-thionyl chloride reaction

Thionyl chloride is often used to convert alcohols into more reactive alkyl chloride, which can be easily converted to many compounds that are not possible from alcohols directly. One important reaction of alkyl chloride is nucleophilic substitution, which is typically conducted under basic conditions. Sulfur dioxide, the by-product from alcohol-thionyl chloride reactions, often reacts with alkyl chloride to form a sulfonyl acid impurity, resulting in yield loss. Therefore, the alkyl chloride is typically isolated to remove the by-products including sulfur dioxide. However, in our laboratory, the alkyl chloride formed from alcohol and thionyl chloride was found to be a potential mutagenic impurity, and isolation of this compound would require extensive safety measures. As a result, a flow-through process was developed, and the sulfur dioxide was purged using a combination of vacuum degassing and nitrogen gas sweeping. An analytical method that can quickly and accurately quantitate residual levels of sulfur dioxide in the reaction mixture is desired for in-process monitoring. We report here a simple ultraviolet (UV) spectrophotometry method for this measurement.This method takes advantage of the dramatic change in the UV absorbance of sulfur dioxide with respect to pH, which allows for accurate quantitation of sulfur dioxide in the presence of the strong UV-absorbing matrix. Each sample solution was prepared using 2 different diluents: 1) 50 mM ammonium acetate in methanol +1% v/v hydrochloric acid, pH 1.3, and 2) 50 mM ammonium acetate in methanol +1% glacial acetic acid, pH 4.0. The buffer solutions were carefully selected so that the UV absorbance of the sample matrix (excluding sulfur dioxide) at 276 nm remains constant. In the pH 1.3 buffer system, sulfur dioxide shows strong UV absorbance at 276 nm. Therefore, the UV absorbance of sample solution is the sum of sulfur dioxide and sample matrix. While in the pH 4.0 buffer system, sulfur dioxide has negligible UV absorbance at 276 nm, and the UV absorbance is attributed only to sample matrix. Quantitation of sulfur dioxide is achieved by subtracting the UV absorbance of sample solution at pH 4.0 from that at pH 1.3. The method is simple but sensitive, with a limit of quantitation of 80 μg L−1. The method linearity was demonstrated from 2 mg L−1 to 40 mg L−1 with an R2 of 0.998, and the spiked recovery ranges from 94% to 105% within the same range. The results are comparable with those obtained using inductively coupled plasma–atomic emission spectrometry (ICP–AES) and gas chromatography–mass spectrometry (GC–MS), suggesting that this method is accurate.

Fast and sensitive determination of sulfur dioxide in herbal medicines by microchip-based field asymmetric-wave ion mobility spectrometry

This paper reports a new method for the direct determination of SO2in HMs using fast field asymmetric-wave ion mobility spectrometry (FAIMS) coupled with a headspace air bubbling method.

Headspace thin-film microextraction coupled with surface-enhanced Raman scattering as a facile method for reproducible and specific detection of sulfur dioxide in wine.

By coupling thin-film microextraction (TFME) with surface-enhanced Raman scattering (SERS), a facile method was developed for the determination of sulfur dioxide (SO2), the most effective food additive in winemaking technology. The TFME substrate was made by free settling of sea urchin-like ZnO nanomaterials on a glass sheet. The headspace sampling (HS) procedure for SO2 was performed in a simple homemade device, and then the SO2 was determined using SERS after uniformly dropping or spraying a SERS-active substrate (gold nanoparticles, AuNPs) onto the surface of the TFME substrate. A reproducible and strong SERS response of the SO2 absorbed onto the ZnO substrate was obtained. After condition optimization, the SERS signal intensity at a shift of 600 cm(-1) and the SO2 concentration showed a good linearity in the range of 1-200 μg/mL, and the linear correlation coefficient was 0.992. The detection limit for SO2 was found to be 0.1 μg/mL. The HS-TFME-SERS method was applied for the determination of SO2 in wine, and the results obtained agreed very well with those obtained using the traditional distillation and titration method. Analysis of variance and Student t test show that there is no significant difference between the two methods, indicating that the newly developed method is fast, convenient, sensitive and has selective characteristics in the determination of SO2 in wine.

Reliability of sulfur dioxide determination method documented in Chinese Pharmacopoeia for evaluating Paeoniae Radix Alba

The content of SO2 in Paeoniae Radix Alba (RPA) was determined by the method documented in Chinese Pharmacopoeia (CP) 2010 edition to validate the repeatability of the method for evaluating RPA, and the contents of paeoniflorin sulfonate in both the residual material and distilled solution of RPA were determined by HPLC to study the transformation of paeoniflorin sulfonate to SO2 by HCl. It was found that the repeatability of the method in CP for evaluating RPA is unacceptable, and paeoniflorin sulfonate was detectable in both the residual material and distilled solution of RPA even at "the end point" of SO2 determination, merely about 50% of paeoniflorin sulfonate was transformed to SO2 by HCl, indicating that the current SO2 determination method in CP is not able to accurately quantify SO2 in RPA. It is recommended that more special method for determining SO2 content in RPA should be developed regarding the chemical characteristics of sulfur-fumigated RPA.

Determination of the wine preservative sulphur dioxide with cyclic voltammetry using inkjet printed electrodes

During winemaking sulphur dioxide is added to prevent undesirable reactions. However, concerns over the harmful effects of sulphites have led to legal limits being placed upon such additives. There is thus a need for simple and selective determinations of sulphur dioxide in wine, especially during winemaking.The simultaneous detection of polyphenols and sulphur dioxide, using cyclic voltammetry at inert electrodes is challenging due to close oxidation potentials. In the present study, inkjet printed electrodes were developed with a suitable voltammetric signal on which the polyphenol oxidation is suppressed and the oxidation peak height for sulphur dioxide corresponds linearly to the concentration.Different types of working electrodes were printed. Electrodes consisting of gold nanoparticles mixed with silver showed the highest sensitivity towards sulphur dioxide.Low cost production of the sensor elements and ultra fast determination of sulphur dioxide by cyclic voltammetry makes this technique very promising for the wine industry.

Determination of sulfur dioxide in traditional Chinese medicine by derivative fluorometry

To establish a derivative fluorometry method for the determination of sulfur dioxide residues in traditional Chinese medicine. The optimal derivation condition was established. The fluorescence intensity was detected at excitation wavelength of 321 nm, and emission wavelength of 384 nm. A linear relationship was obtained between the fluorescence intensity and the addition of reference substance in the range of 0.999 7-17.99 nmol with a correlation coeffient of 0.999 9, and the average recovery was 102.3% with RSD 4.6%. This method is simple and sensitive with quick and correct result. It can provide a reference for the determination of sulfur dioxide residues in traditional Chinese medicine.

Determination of sulfur dioxide in wine using headspace gas chromatography and electron capture detection

Sulfites are routinely added as preservatives and antioxidants in wine production. By law, the total sulfur dioxide content in wine is restricted and therefore must be monitored. Currently, the method of choice for determining the total content of sulfur dioxide in wine is the optimised Monier–Williams method, which is time consuming and laborious. The headspace gas chromatographic method described in this study offers a fast and reliable alternative method for the detection and quantification of the sulfur dioxide content in wine. The analysis was performed using an automatic headspace injection sampler, coupled with a gas chromatograph and an electron capture detector. The method is based on the formation of gaseous sulfur dioxide subsequent to acidification and heating of the sample. In addition to free sulfur dioxide, reversibly bound sulfur dioxide in carbonyl compounds, such as acetaldehyde, was also measured with this method. A total of 20 wine samples produced using diverse grape varieties and vintages of varied provenance were analysed using the new method. For reference and comparison purposes, 10 of the results obtained by the proposed method were compared with those acquired by the optimised Monier–Williams method. Overall, the results from the headspace analysis showed good correlation (R = 0.9985) when compared with the conventional method. This new method requires minimal sample preparation and is simple to perform, and the analysis can also be completed within a short period of time.

Determination of sulfur dioxide in the air of workplace by ion chromatography

目的 建立一种准确测定工作场所空气中二氧化硫含量的新方法.方法 样品溶液中二氧化硫通过离子色谱分离后,与盐酸副玫瑰苯胺溶液反应,在575 nm波长处经紫外-可见检测器检测.结果 二氧化硫在0.5～5mg/L范围内线性关系良好,相关系数为0.9996；以3倍信噪比计算,本法的检出限为0.05 mg/L；若采集7.5 L空气进行测定,最低检出浓度为0.07 mg/m3;不同浓度二氧化硫的相对标准偏差为0.6％～1.2％,回收率为98.3％～108.8％.结论 该方法线性好,灵敏度高,专属性强,可应用于工作场所空气中二氧化硫含量的检测。

Determination of sulfur dioxide in traditional Chinese medicine by alkaline solution extraction and ion chromatography

An ion chromatographic method was developed to analyze sulfur dioxide in traditional Chinese medicine (TCM). The samples were extracted with alkaline solution and reacted with formaldehyde to form hydroxymethyl sulfonic acid. The extracts were cleaned by C18 column and SO3(2-) was determined with ion chromatography equipped with a conductance detector. In the method, AS11-HC chromatographic column was used and the mobile phase was 15 mmol x L(-1) KOH. The calibration curve was in good linearity in the range of 1 to 100 microg (r =0.9992). The detection limit was 0.53 mg x kg(-1) and the average recovery was 103.7%. The method is simple, sensitive, precise, short-time-consuming, and the random error is smaller, which is applicable to the testing of large quantity batches of TCM.

Development of a Gas Diffusion Multicommuted Flow Injection System for the Determination of Sulfur Dioxide in Wines, Comparing Malachite Green and Pararosaniline Chemistries

A flow system based on the multicommutation concept was developed for the determination of free and total sulfur dioxide in table wines, exploiting gas diffusion separation and spectrophotometric detection. The system allowed the comparison of malachite green and pararosaniline chemistries, using the same manifold configuration. Free and total SO(2) were determined within the ranges 1.00-40.0 and 25.0-250 mg L(-1), at determination throughputs of 25 and 23 h(-1), respectively. Employing the malachite green reaction, detection limits of 0.3 and 0.8 mg L(-1) were attained for free and total SO(2), respectively. Pararosaniline chemistry provided detection limits of 0.6 mg L(-1) for free SO(2) and 0.8 mg L(-1) for total SO(2). Relative standard deviations better than 1.8 and 1.4% were obtained by the malachite green and pararosaniline reactions, respectively. With regard to the two tested chemistries, 18 wines were analyzed and the results achieved by the pararosaniline reaction compared better with those furnished by the recommended procedure.

Simple spectrophotometric method for the determination of sulfur dioxide by its decolorizing effect on the peroxovanadate complex

A simple, rapid, and economical spectrophotometric method is developed for the determination of sulfur dioxide in sugar and air samples. The developed method is based on a red-brown peroxovanadate complex (λmax = 470 nm) produced in 2 M sulfuric acid when ammonium metavanadate is treated with hydrogen peroxide. Under fixed concentrations of hydrogen peroxide and ammonium metavanadate, when sodium metabisulfite (Na2S2O5 = 2SO2) is added, it preferentially reacts with hydrogen peroxide producing sulfuric acid, and the unreacted hydrogen peroxide then reacts with ammonium metavanadate; therefore, the concentration of sulfur dioxide is directly proportional to a decrease in the concentration of the peroxovanadate complex. The stoichiometric ratio between hydrogen peroxide and ammonium metavanadate as well as the stability constant of the complex are determined by the modified Job’s method and the respective values are found to be 1: 1 and 2.5 × 104 mol−1 L, respectively. The system obeys Lambert-Beer’s law in the concentration range 3.57–64.26 ppm of sulfur dioxide. The molar absorptivity, correlation coefficient, and Sandell’s sensitivity values are found to be 0.649 × 103 L mol−1 cm−1, 0.9908, and 0.1972 μg cm−2, respectively. The method is applied to the determination of sulfur dioxide present in commercial sugars and air samples. The results obtained are reproducible with a standard deviation of 0.02–0.05. For method validation, sulfur dioxide is also determined separately following the AOAC method for an air sample and the ICUMSA method for commercial sugars. The results obtained by the developed and official methods are in good agreement.