Use Of Sodium Thiosulfate Research Articles

Engineering Escherichia coli for efficient glutathione production

Glutathione is a tripeptide of excellent value in the pharmaceutical, food, and cosmetic industries that is currently produced during yeast fermentation. In this case, glutathione accumulates intracellularly, which hinders high production. Here, we engineered Escherichia coli for the efficient production of glutathione. A total of 4.3 g/L glutathione was produced by overexpressing gshA and gshB, which encode cysteine glutamate ligase and glutathione synthetase, respectively, and most of the glutathione was excreted into the culture medium. Further improvements were achieved by inhibiting degradation (Δggt and ΔpepT); deleting gor (Δgor), which encodes glutathione oxide reductase; attenuating glutathione uptake (ΔyliABCD); and enhancing cysteine production (PompF-cysE). The engineered strain KG06 produced 19.6 g/L glutathione after 48 h of fed-batch fermentation with continuous addition of ammonium sulfate as the sulfur source. We also found that continuous feeding of glycine had a crucial role for effective glutathione production. The results of metabolic flux and metabolomic analyses suggested that the conversion of O-acetylserine to cysteine is the rate-limiting step in glutathione production by KG06. The use of sodium thiosulfate largely overcame this limitation, increasing the glutathione titer to 22.0 g/L, which is, to our knowledge, the highest titer reported to date in the literature. This study is the first report of glutathione fermentation without adding cysteine in E. coli. Our findings provide a great potential of E. coli fermentation process for the industrial production of glutathione.

Use of Sodium Thiosulfate as an Otoprotectant in Patients With Cancer Treated With Platinum Compounds: A Review of the Literature.

Hearing loss occurs in 50%-70% of children treated with cisplatin. Scientific efforts have led to the recent approval of a pediatric formula of intravenous sodium thiosulfate (STS) for otoprotection by the US Food and Drug Administration, the European Medicines Agency, and the Medicines and Health Regulatory Authority in the United Kingdom. To inform stakeholders regarding the clinical utility of STS, the current review summarizes available literature on the efficacy, pharmacokinetics (PK), and safety of systemic STS to minimize cisplatin-induced hearing loss (CIHL). A comprehensive narrative review is presented. Thirty-one articles were summarized. Overall, systemic STS effectively reduces CIHL in the preclinical and controlled clinical study settings, in both adults and children with cancer. The extent of CIHL reduction depends on the timing and dosing of STS in relation to cisplatin. Both preclinical and clinical data suggest that systemic STS may affect plasma platinum levels, but studies are inconclusive. Delayed systemic administration of STS, at 6 hours after the cisplatin infusion, does not affect cisplatin-induced inhibition of tumor growth or cellular cytotoxicity in the preclinical setting, nor affect cisplatin efficacy and survival in children with localized disease in the clinical setting. Systemic administration of STS effectively reduces the development and degree of CIHL in both the preclinical and clinical settings. More studies are needed on the PK of STS and cisplatin drug combinations, the efficacy and safety of STS in patients with disseminated disease, and the ability of STS to prevent further deterioration of pre-established hearing loss.

HIPEC morbidity and implications for post-surgical treatment. A medical oncologist advice

The fear that the medical oncologist may have is that HIPEC integrated into a multidisciplinary care pathway will negatively impact the treatments that will follow. This fear is largely related to the side effects, which are themselves dependent on the medication used. Cisplatin, most frequently used for epithelial ovarian cancers, has essentially renal toxicity, which can be avoided by the use of sodium thiosulfate. Oxaliplatin induces more severe toxicities post surgery than mitomycin C in colorectal cancers. However, the data from randomized trials are reassuring for the medical oncologist concerning the course of postoperative treatment, as long as HIPEC is performed according to a standardized protocol, within trained teams, and after multidisciplinary discussion concerning its modalities.

Effect of calcium hypochlorite and sodium thiosulfate on the bond strength to pulp chamber dentin: A laboratory investigation.

This study aimed to compare the effect of sodium hypochlorite (NaOCl) and calcium hypochlorite [Ca(OCl)2 ] on the bond strength to pulp chamber dentin when followed or not by the use of sodium thiosulfate (Na2 S2 O3 ). The pulp chamber of fifty human molars were divided into five groups (n=10) according to the immersion protocol: 2.5% NaOCl; 2.5% NaOCl + 5% Na2 S2 O3 ; 2.5% Ca(OCl)2 ; 2.5% Ca(OCl)2 + 5% Na2 S2 O3 ; and 0.9% sodium chloride (NaCl; control). Subsequently, the samples were restored with resin composite. Three sticks each were obtained and subjected to microtensile testing. SEM/EDS analyses of the pulp chamber roof (n=8) were carried out for mineral quantification. Elemental analysis data were investigated via one-way ANOVA and Tukey's post hoc, and bond strength data by post hoc pairwise comparisons using the Kruskal-Wallis test. Use of 2.5% NaOCl was associated with the lowest value of bond strength, while 2.5% Ca(OCl)2 had similar bond strength to that of the 0.9% NaCl control. Using 5% Na2 S2 O3 was able to increase the bond strength after 2.5% NaOCl, but not after 2.5% Ca(OCl)2 . The group treated only with 2.5% Ca(OCl)2 had a higher Ca/P ratio on the dentin surface. Dentin treated with Ca(OCl)2 was not affected by Na2 S2 O3 and showed bond strength similar to the 0.9% NaCl.

The use of sodium thiosulfate in the treatment of hemorrhoids

Hemorrhoidal disease is one ofthe most common pathologies ofthe anorectal region, its specific weight in the structure of diseases ofthe colon is about 40%. Hemorrhoids are a socially significant disease, most often found in the able-bodied population. The reason for the development of hemorrhoids, on the one hand, is a violation of blood circulation in the cavernous corpuscles, due to which they increase and nodes form, and on the other hand, dystrophic changes in the ligamentous apparatus of hemorrhoids, in connection with which they gradually shift down and begin to fall out of the anal canal. One of the factors provoking the development of hemorrhoidal disease may be the presence of dissinergia of the pelvic floor muscles, which, in accordance with the Roman criteria IV, is part of the functional constipation syndrome. Not only dissinergia, but also high basal pressure in the anal canal (increased tone of the internal anal sphincter) can lead to stool retention. High rates of basal anal pressure can occur as a result of damage to the mucous membrane of the anal canal during straining, which leads to reflex spasm of the anal sphincter (anal continuity reflex). Thus, a vicious circle can form and thereby exacerbate constipation and the course of hemorrhoidal disease. Also, the relationship between dysenergic defecation and hemorrhoidal disease can be justified by the fact that physiotherapy aimed at correcting the work of the pelvic floor muscles contributes to better control over the manifestations of hemorrhoidal disease in complex therapy. The return of symptoms or, in other words, the recurrence of the disease in patients after surgery for hemorrhoids more often occurs with concomitant constipation. In accordance with clinical recommendations for the treatment of hemorrhoids, the use of an adequate amount of fluid and the intake of dietary fiber (fiber preparations) is indicated to normalize the activity of the gastrointestinal tract and eliminate constipation as part of complex therapy. If it is impossible to take dietary fiber, laxatives come to the fore of constipation therapy. This article presents clinical examples of the efficacy and safety of using sodium picosulfate.

Clinical features and outcomes of calciphylaxis in Chinese patients with chronic kidney disease.

Calciphylaxis is a rare disease, predominantly in chronic kidney disease (CKD), characterized by high morbidity and mortality. Data from the Chinese population have been an invaluable resource for a better understanding of natural history, optimal treatments and outcomes of calciphylaxis. A retrospective study was conducted in 51 Chinese patients diagnosed with calciphylaxis at Zhong Da Hospital affiliated to Southeast University from December 2015 to September 2020. Between 2015 and 2020, 51 cases of calciphylaxis were registered in The China Calciphylaxis Registry (http://www.calciphylaxis.com.cn), which was developed by Zhong Da Hospital. The mean age of the cohort was 52.02 ± 14.09 years, and 37.3% were female. Forty-three patients (84.3%) were on haemodialysis, with a median dialysis vintage of 88 months. Eighteen patients (35.3%) had a resolution of calciphylaxis and 20 patients (39.2%) died. Patients in later stages had higher overall mortality than those in earlier stages. Delay from skin lesions onset to diagnosis and calciphylaxis-related infections were risk factors in both early and overall mortality. Additionally, dialysis vintage and infections were significant risk factors in calciphylaxis-specific mortality. Among therapeutic strategies, only the use of sodium thiosulfate (STS) ≥3 courses (14 injections) was significantly associated with decreased hazard of death in both early and overall mortality. For Chinese patients with calciphylaxis, delay from skin lesions onset to diagnosis and infections secondary to wounds are risk factors for the prognosis of patients with calciphylaxis. Additionally, patients in earlier stages have better survival and early continuous use of STS is highly suggested.

33641 Treatments of calcinosis cutis in autoimmune connective tissue diseases

Calcinosis cutis is often seen in the setting of autoimmune connective tissue disease (ACTD). Treatment for calcinosis cutis is often difficult and unsuccessful. We sought to evaluate outcomes at our institution of treatments for calcinosis cutis. A search in the patient data registry was conducted to select patients with the diagnosis of calcinosis cutis and ACTD at Massachusetts General Hospital and Brigham Women’s Hospital. Out of 220 charts, 43 patients were identified with adequate documentation to assess outcomes and the diagnosis of calcinosis cutis in provider notes with underlying ACTD. 86.0% of patients had some form of medical intervention and 39.5% of patients underwent surgical excision. 44.2% of patients had no response or resolution of their calcinosis in response to treatments. 39.5% of patients indicated partial resolution of calcinosis cutis. Only 25% of patients with a documented partial response was due to medical therapy. There was often no physical examination documentation from the provider demonstrating a reduction from the previous examination. In our case-series we found that results are few and far between. Complete resolution was only seen through surgical excision of nodules or through the use of sodium thiosulfate on small lesions (<3 mm). Additionally, many of the patients that were categorized as a partial reduction was largely due to self-reported improvement. In future, accurate documentation of calcinosis lesion sizes and locations by text or photographs would provide more rigorous data, rather than depending on patient self-reported improvement, which could be influenced by a placebo effect.

Sodium Thiosulfate Reduces Acute Kidney Injury in Patients Undergoing Cytoreductive Surgery Plus Hyperthermic Intraperitoneal Chemotherapy with Cisplatin: A Single-Center Observational Study

BackgroundCytoreductive surgery (CRS) in combination with hyperthermic intraperitoneal chemotherapy (HIPEC) represents a multimodal treatment concept for patients with peritoneal surface malignancies. The use of intraperitoneal cisplatin (CDDP) is associated with a risk of acute kidney injury (AKI). The aim of this study is to evaluate the protective effect of perioperative sodium thiosulfate (STS) administration on kidney function in patients undergoing CRS and CDDP-based HIPEC.Patients and MethodsWe retrospectively analyzed clinical data of all patients who underwent CRS and CDDP-based HIPEC at our hospital between March 2017 and August 2020. Patients were stratified according to the use of sodium thiosulfate (STS vs. no STS). We compared kidney function and clinical outcome parameters between both groups and determined risk factors for postoperative AKI on univariate and multivariate analysis. AKI was classified according to acute kidney injury network (AKIN) criteria.ResultsOf 238 patients who underwent CRS and CDDP-based HIPEC, 46 patients received STS and 192 patients did not. There were no significant differences in baseline characteristics. In patients who received STS, a lower incidence (6.5% vs. 30.7%; p = 0.001) and severity of AKI (p = 0.009) were observed. On multivariate analysis, the use of STS (OR 0.089, p = 0.001) remained an independent kidney-protective factor, while arterial hypertension (OR 5.283, p < 0.001) and elevated preoperative urea serum level (OR 5.278, p = 0.032) were predictors for postoperative AKI.ConclusionsThe present data suggest that STS protects patients from AKI caused by CRS and CDDP-based HIPEC. Further prospective studies are needed to validate the benefit of STS among kidney-protective strategies.

Effect of Sodium Thiosulfate on Interfacial Adaptation and Penetration of an Epoxy Resin-Based Root Canal Sealer.

Our study evaluated the impact of sodium thiosulfate (ST) irrigation, subsequent to sodium hypochlorite (NaOCl) and just before root canal filling, on the filling quality (interfacial adaptation and penetration segment) of an epoxy resin-based root canal sealer. Twenty single-rooted human teeth were prepared with the ProTaper system. The specimens were then divided into the following groups: 5.25% NaOCl irrigation (NaOCl group) and 5.25% NaOCl irrigation+0.5% sodium thiosulfate (NaOCl+ST group). The root canals were filled using single-cone technique with ProTaper F3 cones and AH-Plus sealer, labeled with rhodamine B dye to allow analysis under a confocal laser scanning microscopy (CLSM). All samples were sectioned at 2, 4, and 6 mm from the apex and prepared for CLSM analysis. The percentage of voids, gaps and dentinal sealer penetration segment of the canal were calculated at the apical, middle and coronal thirds. The non-parametric Mann-Whitney statistical test was used at 5% significance level. Higher percentage of gaps and voids were observed at all root thirds of the NaOCl group when compared to the NaOCl+ST group (P<0.05). There was a significant increase in the penetration segment of NaOCl+ST group at the coronal and middle root third when compared to the NaOCl group (P<0.05). Our in vitro results showed that the use of ST as an antioxidant agent after NaOCl irrigation promoted a better interfacial adaptation and penetration of epoxy resin-based root canal fillings.

The para-chloroaniline prevention after the use of sodium thiosulfate as an intermediary irrigator between sodium hypochlorite and chlorhexidine

Objective: Evaluating the neutralization of sodium hypochlorite (NaOCl) by sodium thiosulfate in vitro, in different concentrations, in the prevention of para-chloroaniline (PCA) formation when in contact with CHX. Material and methods: It were collected 2 mL of NaOCl solution to 2.5% and to 6%, divided in eight groups according to the sodium thiosulfate concentration (1.0; 2.5; 5.0; 10%) (TSF). The tests were done in duplicate and in each plate, it was poured 2mL of TFS and the reaction was observed for 5 minutes. After, 2 mL of 2% Chlorhexidine (CHX) were pouring on the plates to verify the formation of PCA. The infrared spectroscopy with Fourier transform was used to verify the presence of PCA, and, in each solution, the pH was verified with universal strip. Results: All analyzed samples presented presence of water and deuterium water, and there was not identification of the PCA presence. The pH result of the solutions was between 8 and 9. It was verified that in the increasing of the concentration of the TFS there was gradual formation of precipitated compound and increase of the turbidity of the final sample. Conclusion: TFS can be used as an intermediate irrigation solution to prevent the formation of para-chloroaniline in the combined use of NaOCl and CHX.

Assaying the use of sodium thiosulphate as a biostimulant and its effect on cadmium accumulation and tolerance in Brassica oleracea plants.

An optimal uptake of mineral elements is crucial to ensure both crop yield and quality. The use of biostimulants is taking relevance to improve the nutrition of crops. Sulphur (S) is one of the elements with great potential within biostimulants. Furthermore, soil contamination by heavy metals such as cadmium (Cd) has become a serious environmental problem. Different studies have suggested the use of thiosulphate (TS) as a biostimulant and to increase the phytoremediation capacity of plants. Therefore, in the present study, we use a crop plant with high S requirements such as Brassica oleracea, to test whether TS serves as a biostimulant and whether affects Cd accumulation and tolerance. B. oleracea plants were grown with two different TS doses (2mM and 4mM), under Cd toxicity, and with the combination of Cd toxicity and both TS doses. Parameters of biomass, mineral elements accumulation, and stress tolerance were analyzed. The results showed that TS reduced biomass of B. oleracea plants. The application of 2mMTS increased Cd accumulation whereas the 4mM dose reduced it. On the other hand, TS incremented micronutrient accumulation on plants subjected to Cd toxicity and increased Zn contents. Besides, the application of 2mM to Cd-stressed plants enhanced photosynthesis performance and reduced oxidative stress. Finally, TS increased the antioxidant capacity of B. oleracea plants. Briefly, although TS can not be used as a biostimulant it could be used for Cd phytoremediation purposes and to enhance Zn accumulation in B. oleracea plants.

An improved process methodology for extracting cobalt from zinc plant residues

Zinc plant residue contains valuable metals that can be reused as a source for obtaining these metals. This paper describes the use of sodium thiosulfate (Na2S2O3) in leaching of Co and Mn from zinc plant residue, and purifying the leach solution in order to obtain a pure solution of Co(II). After dissolution of zinc using sulfuric acid, Co and Mn were dissolved in H2SO4 in the presence of a reducing agent. The effects of temperature, acid percentage, type and concentration of reducing agent on dissolution were studied. The results for sodium thiosulfate showed the dissolution of 90.7% and 87.6% Co and Mn, respectively at 65 °C, with an acid concentration of 5% and sodium thiosulfate concentration of 6 g/L. The corresponding results in the presence of H2O2 as a reducing agent are 94.7% Co, 96.3% Mn at 50 °C with the same acid and reagent concentration. An analysis of variation (ANOVA) on the corresponding data was performed. A new correlation as a function of reducing agent yielding the recovery for Co and Mn was derived. Moreover, the purification process of metals was investigated which was a combination of the precipitation method for removing iron, and the solvent extraction for separating Co(II) and Mn(II). The factors influencing solvent extraction i.e., pH, organic concentration, and organic/aqueous ratio were optimized. Finally, two processes for extracting Co and Mn from the hot filter cake (HFC) were proposed and compared.

Medical interventions for the prevention of platinum-induced hearing loss in children with cancer.

Medical interventions for the prevention of platinum-induced hearing loss in children with cancer.

Sustainable supercapacitor electrodes produced by the activation of biomass with sodium thiosulfate

High-surface area carbons are produced from biomass-based products (wood sawdust and tannic acid) by means of an environmentally friendly process based on the use of sodium thiosulfate as activating agent and an inert salt (KCl) that serves as a confinement medium for the activation reaction. These porous carbons have high BET surface areas of up to 2650 m2 g-1, large pore volumes of up to 2.3 cm3 g-1 and a porosity that combines micro- and mesopores in different amounts depending on the quantity of activating agent employed. Such carbons have two additional remarkable properties: a) they are S-doped (2–6 wt% S) and b) they have good electrical conductivities in the 2.5–4.5 S cm-1 range. The above properties make these carbon materials highly attractive as supercapacitor electrodes. Indeed, when tested in a variety of electrolytes (H2SO4, TEABF4/AN and EMImTFSI) using commercial-level mass loadings, they show high specific capacitances (up to 200 F g-1, 140 F g-1 and 160 F g-1 in aqueous, organic and ionic liquid electrolytes, respectively) and high capacitance retention at high rates in all the electrolytes in combination with a good stability under cycling and floating modes.

Calciphylaxis in a renal transplant recipient with normal graft function: A case report and review of literature

Calciphylaxis, also known as calcific uremic arteriolopathy, is a rare, life-threatening complication of end-stage renal disease. However, it may also occur in patients without renal failure, the nonuremic calciphylaxis. Most patients present with painful skin ulcers. Delayed diagnosis can lead to sepsis-related morbidity and mortality. Aberrations in calcium, phosphate, and parathyroid hormone physiology are common and biopsy is diagnostic. Early diagnosis and correction of vascular and metabolic aberrations may assist in healing as may the use of sodium thiosulfate and hyperbaric oxygen therapy. We report on successful treatment of a case of calciphylaxis in a renal transplant recipient with normal allograft function.

A Green Route to High-Surface Area Carbons by Chemical Activation of Biomass-Based Products with Sodium Thiosulfate

A simple, sustainable, and affordable approach for the synthesis of highly porous carbons is presented. The procedure is based on the use of sodium thiosulfate as an activating agent and a variety of biomass-based products (glucose, sucrose, and gelatine) as carbon precursors. The synthesis scheme involves three steps: (a) mixing the reactants by grinding, (b) heat treatment at temperatures in the 800–900 °C range, and (c) extracting the carbon material from the carbonized solid by simple washing with water. The generation of the pore structure is based on the redox reaction between the carbonaceous matter and sodium thiosulfate acting as an oxidant. In this way, porous carbons with high BET surface areas in the ∼2000–2700 m2 g–1 range and large pore volumes of up to 2.4 cm3 g–1 are obtained. The porosity of these carbons consists of two pore systems made up of narrow micropores of 0.8 nm and larger pores of up to 5 nm. These porous carbons have a certain amount of sulfur (∼2–3%) that is incorporated into...

Dissolving calcium hydroxylapatite filler with the use of sodium thiosulfate: A proof-of-concept clinical study

Dissolving calcium hydroxylapatite filler with the use of sodium thiosulfate: A proof-of-concept clinical study

Physico-Chemical Stability of Sodium Thiosulfate Infusion Solutions in Polyolefin Bags at Room Temperature over a Period of 24 Hours

Abstract Background Many publications described sodium thiosulfate used to prevent the renal toxicity induced by cisplatin hyperthermic intraperitoneal chemotherapy. After around 60 or 90 minutes of hyperthermic chemotherapy, cisplatin was drained and then, sodium thiosulfate was infused by intravenous route. Sodium thiosulfate is used in two steps: a first step, at 9 g/m2 in 250 mL of 0.9 % sodium chloride over 10 minutes followed by a second step, at 12 g/m2 in 1000 mL of 0.9 % sodium chloride over 6 hours. The purpose of this work was to study the stability of sodium thiosulfate at 16 mg/mL in 0.9 % sodium chloride polyolefin bags 1000 mL and at 72 mg/mL in 0.9 % sodium chloride polyolefin bags 250 mL, at 25 °C, protected or unprotected from light. Methods Chemical stability was analysed by high performance liquid chromatography (HPLC) coupled to a photodiode array detector after preparation and after 6-hour or 24-hour storage. The method was validated according to the International Conference on Harmonisation (ICH). Physical stability was evaluated by visual and subvisual inspection (turbidimetry by UV spectrophotometry at 550 nm). Three bags for each condition were prepared. On each time of the analysis, three samples were prepared for each bag and analysed by HPLC. pH values were evaluated on each moment of the analysis. Results Sodium thiosulfate solutions diluted in 0.9 % sodium chloride at 16 and 72 mg/mL retained more than 95 % of the initial concentration during 24 hours. Concerning pH measurements, the maximum variation was 0.24 pH unit. No visual modification such as colour change, precipitation or gas formation was observed. The absorbance at 550 nm obtained for each sample was less than 0.010 AU. Conclusions Sodium thiosulfate solutions at 16 mg/mL in 1000 mL 0.9 % sodium chloride and at 72 mg/mL in 250 mL 0.9 % sodium chloride are stable physically and chemically over a period of 24 hours at 25 °C, with or without protection from light. This stability study allows the use of sodium thiosulfate in renal protection protocols during cisplatin hyperthermic intraperitoneal chemotherapy.

Effect of irrigant neutralizing reducing agents on the compromised dislocation resistance of an epoxy resin and a methacrylate resin-based root canal sealer in vitro

ObjectivesTo determine the effect of two reducing agents (sodium ascorbate and sodium thiosulfate) on the dislocation resistance of a methacrylate and an epoxy resin based root canal sealer to sodium hypochlorite (NaOCl) treated root canal dentin. Materials and methodsSingle rooted teeth (n = 60) were instrumented with rotary instruments with an irrigation protocol of 3% NaOCl, 17% EDTA and 3% NaOCl in a sequence. Samples were randomly divided into three groups (n = 20) based on the final treatment: group 1 (saline), group 2 (5% sodium thiosulfate), group 3 (10% sodium ascorbate). Samples were then randomly divided into two subgroups (n = 10) based on the root canal sealer: A (a methacrylate resin sealer; EndoREZ); B (an epoxy resin sealer; AH Plus). The dislocation resistance was assessed using the push out bond strength test. The data were statistically analyzed by three-way ANOVA and a pair-wise comparison was done using the Bonferroni adjustment (P = 0.05). ResultsThere was a significant interaction between the root thirds and the final treatment protocol for EndoREZ (P < 0.001) but not AH Plus (P > 0.05). The two experimental protocols significantly improved the adhesion (bond) strength of EndoREZ compared to saline (P < 0.05) with sodium thiosulfate producing significantly higher values than sodium ascorbate (P < 0.05). Both reducing agents did not improve the adhesion strength of AH Plus significantly when compared to the control (P > 0.05). ConclusionsThe bond strength of the methacrylate resin sealer EndoREZ is improved by the use of sodium thiosulfate and sodium ascorbate after irrigation with NaOCl, but these reducing agents do not improve the bond strength of the epoxy resin sealer AH Plus. Root canal sealers are differentially influenced by irrigant neutralizing (reducing) agents.

Use of Sodium Thiosulfate to Quench Hypochlorite Solutions Prior to Chlorate Analysis

Sodium thiosulfate is a commonly used quenching agent for sodium hypochlorite and has previously been deemed acceptable when quenching hypochlorite solutions before conducting chlorate analysis. However, using thiosulfate to quench hypochlorite solutions with compositions similar to those produced by electrolytic onsite generation process (OSG; free available chlorine content of 0.8% with a pH range of 8–10) can result in artificially low chlorate measurements. Reactions between thiosulfate and hypochlorite can result in a substantial decrease in pH that in turn causes the production of bisulfite ions from thiosulfate. In turn, these ions react with chlorate ions, resulting in artificially decreased measurements of chlorate in the initial hypochlorite solutions. Malonic acid does not cause a similar effect when used as a hypochlorite quenching agent and should therefore be used in place of thiosulfate when conducting chlorate analysis of hypochlorite solutions produced through electrolytic OSG processes.