High-performance liquid chromatography using diode array detector and fluorescence detector for hydrogen peroxide analysis in processed fishery foods (2024)

Reagents and equipment

Hydrogen peroxide (30%, w/v), coumarin, ferrous sulfate, formic acid, and ammonium metavanadate were purchased from Sigma-Aldrich (St. Louis, MO, USA). Water, methanol, acetonitrile, ethanol, and hexane (HPLC grade) were products of Honeywell Burdick & Jackson (Ulsan, Korea). A 1N H₂SO₄ solution (extra pure grade) was obtained from Samchun Chemicals (Pyeongtaek, Korea).

Agilent Technologies 1260 Infinity series (Agilent Technologies, Santa Clara, CA, USA), equipped with a binary pump VL (G1312C), degasser (G1322A), thermostatted column compartment (G1316A), automatic sampler (G1329A), 1260 fluorescence detector (FLD, G1321B), and 1260 diode array detector (DAD, G1315D), was used for the HPLC analysis of H₂O₂. Eclipse XDB–C18 (I.D. 4.6 × 250mm, particle size 5μm, Agilent Technologies, Santa Clara, CA, USA) was applied for this analysis. An Accela HPLC system (Thermo Fisher Scientific, San Jose, CA, USA) equipped with an LTQ–Velos pro LC-MSn (Thermo Fisher Scientific, San Jose, CA, USA) was used to verify 7-hydroxycoumarin, a derivative compound from Fenton reaction between H₂O₂ and coumarin.

Preparation of solutions

A stock solution (1000mg/L, 29.41mM) of H₂O₂ was prepared by the dilution of 30% H₂O₂ (w/t) with deionized water. It was then diluted with distilled water to make standard solutions with final concentrations in the range of 0.5–100mg/L (14.71–2941.17μM) for HPLC–DAD analysis and 5–400μg/L (0.15–11.76μM) for HPLC–FLD analysis. All H₂O₂ solutions were freshly prepared before analysis considering its high volatility.

Derivatization for hydrogen peroxide analysis

It is difficult to analyze pure H₂O₂ solution because of its volatile characteristics. In this study, two previously reported derivatization reactions (Perkowski et al., 2006; Zhang et al., 2013) for spectrophotometric analysis were applied to measure H₂O₂ levels with the HPLC system.

Vanadium(V) reacts quantitatively with H₂O₂ in acidic conditions, leading to the formation of vanadium(V)-peroxo complex with a red-brown color; metavanadate was applied for the formation of this complex (Zhang et al., 2013). Ammonium metavanadate was dissolved in 1N sulfuric acid solution to prepare 1% ammonium metavanadate solution (1%, v/v). The solution should be used 1week after preparation and may be used up to a month. The solution (0.1mL) was added to an aqueous solution (0.9mL) containing H₂O₂. The mixture was filtered through 0.45-μm PVDF syringe filter and then immediately used as a test solution for analysis using HPLC–DAD.

In Fenton reaction, iron(II) ions and H₂O₂ react together to generate hydroxyl radical (Perkowski et al., 2006). The latter can oxidize coumarin to produce 7-hydroxycoumarin (also known as umbelliferone), which has strong fluorescence (Guan et al., 2008; Ishibashi et al., 2000). Here, 0.67mM coumarin solution was prepared with HPLC grade to minimize any interference in HPLC analysis. Since coumarin does not solubilize in water, it was heated and stirred at 95°C for 1h. Thereafter, the solution was cooled at 4°C. Ferrous sulfate solution (12.5mM) was prepared in 0.5mM sulfuric acid; 1mL of the solution was added to the coumarin solution (30mL), and pH of the mixed solution was adjusted to 3 with 0.25N sulfuric acid solution (Abbas et al., 2010). The resulting solution (2mL) was then added to an aqueous solution (3mL) containing H₂O₂, and the mixture was retained for 7min after vigorous mixing using a vortex mixer. The prepared solution was filtered through 0.45-μm PVDF syringe filter before injection into the HPLC–FLD system.

HPLC analysis

An HPLC system equipped with DAD was used to analyze H₂O₂, derivatized as the vanadium(V)-peroxo complex, using Eclipse XDB-C18 analytical column (I.D. 4.6 × 250mm, particle size 5μm, Agilent Technologies, Santa Clara, CA, USA) at 30°C. Analysis was performed under isocratic condition at a flow rate of 0.8mL/min with water and methanol (75:25, v/v) as the mobile phase. Twenty microliters of the derivatized H₂O₂ were observed at 454nm.

An HPLC system equipped with FLD was used to analyze the H₂O₂ derivatized as hydroxycoumarin. The excitation and emission wavelengths were 330 and 460nm, respectively. Separation was carried out on an Eclipse XDB C18 column (I.D. 4.6 × 250mm, particle size 5μm) at 40°C with an injection volume of 50 μL. The mobile phase consisted of water and acetonitrile (50:50, v/v) containing 1% acetic acid, and flow rate was set at 1mL/min.

Identification of the 7-hydroxycoumarin derived from H₂O₂ with liquid chromatography with tandem mass spectrometry (LC–MS/MS)

LC–ESI–MS/MS was used to identify the 7-hydroxycoumarin derived from H₂O₂ by Fenton reaction. Analytical conditions of LC–ESI–MS/MS to identify 7-hydroxycoumarin are described in Table ​Table11.

Sample preparation

A total of 300 samples were analyzed with the 2 methods (150 samples each). The food samples were purchased between 2016 and 2022 from the market and online retailers in South Korea. The samples for each method were classified into 5 categories according to the Korea Food Code: processed fishery foods (n = 71), processed agricultural foods (n = 13), noodles (n = 27), milk products (n = 9), and beverage (n = 30). The products were randomly collected with or without labelling. Processed fishery food was selected the as representative food for analysis because H₂O₂ can be easily used for bleaching and preventing microbial contamination for this type of food. All samples were stored at −20°C until use.

Weighed food samples (3g) were cut into 10-mm pieces, and the analysis sample (3g or 3mL) was added in deionized water (30mL) at 4°C before the extraction step. The mixture was vortexed for 30s and centrifuged at 16,000×g for 10min at 4°C. In case of high-fat food samples, H₂O₂ was extracted after fat removal with hexane (Fig.1). The supernatant was collected after centrifugation and filtered through a Whatman PVDF syringe filter (pore size, 0.45μm) before HPLC injection.

Method validation

Both HPLC–DAD and HPLC–FLD methods were further validated using parameters such as linearity, limit of detection (LOD), limit of quantification (LOQ), accuracy, and precision, according to ICH Harmonised Tripartite Guideline (ICH Harmonised Tripartite, Guideline, 2005).

Calibration curves were constructed in the range of 0.5–100mg/L using HPLC–DAD and in the range of 5–400μg/L using HPLC–FLD. Linearity was estimated in terms of regression of the calibration curve. The LOD and LOQ were assessed using the signal-to-noise ratio, as reported by Ivanova et al. (2019). Precision was evaluated by 3 repeated measurements for various concentrations of H₂O₂ and was expressed as percent relative standard deviation (%RSD). The tested concentrations were included in the range of 5 to 100mg/L for HPLC–DAD method and 10 to 400μg/L for HPLC–FLD method. Recovery tests were performed to estimate accuracy according to the ICH guideline (ICH Harmonized Tripartite, Guideline, 2005) in the range of 10–100mg/L and 25–400μg/L for the HPLC–DAD and HPLC-FLD method, respectively. Three food categories (processed fishery products, dairy products, and noodles) were selected for testing, and a blank sample containing no H₂O₂ was used as a matrix for recovery testing.

HPLC analysis of standard solutions

Analysis of H₂O₂ with HPLC–DAD was based on the measurement of vanadium(V)-peroxo complex derived from the reaction of H₂O₂ with vanadium(V). As shown in Fig.2(A), vanadium(V)-peroxo complex was successfully detected at a retention time of 2.79min in this analysis system. The peak height of vanadium(V)-peroxo complex was proportional to the concentration of H₂O₂ present in the solution, and it correlated with the amount of ammonium metavanadate (NH₄VO₃) solution with the same H₂O₂ concentration. To observe linearity in the calibration curve, the ratio of H₂O₂ solution to 1% ammonium metavanadate solution was optimized as 1:9. Any increase of metavanadate over 9 in proportion did not increase the formation of vanadium(V)-peroxo complex further. A similar finding was reported by Zhang et al. (2013), in which a ratio of 2.2 (V₂O₅:H₂O₂ = 2.2:1) was applied for the ratio of vanadium pentoxide to H₂O₂ in spectrophotometric assay. Bortolini and Conte (2005) reported hydrogen peroxide to readily combine with vanadium(V), forming a number of peroxo-vanadates whose essence depended on pH and relative concentration of the reagents.

In HPLC–FLD analysis, H₂O₂ was detected based on the presence of 7-hydroxycoumarin derived from Fenton reaction. Fenton reaction is an oxidation process between an aqueous solution of H₂O₂ and a ferrous salt, and ferrous ions (Fe²⁺) strongly catalyze the process. The efficiency of oxidation is the highest at pH 2–5 (Perkowski et al., 2006). In this study, to increase the oxidation efficiency of Fenton reaction, the coumarin solution with ferrous sulfate was adjusted to pH 3 with 0.25N sulfuric acid solution. The 7-hydroxycoumarin produced from Fenton reaction showed strong fluorescence property, which was detected using HPLC–FLD. The compound was detected at 3min after the injection (Fig.2(B)). The newly developed method exhibited a good separation of 7-hydroxycoumarin with a symmetrical peak and a short running time (10min). The column used in HPLC–DAD analysis was applied in the HPLC–FLD method. A mixture of water and acetonitrile containing 1% acetic acid (50:50, v:v) was used as the mobile phase in isocratic elution conditions.

In 2019, a spectrophotometric method for the detection of trace H₂O₂, based on the oxidative coloration reaction of N,N′-diethyl-p-phenylenediamine (DPD) via Fenton reactions in aqueous water (Zou et al., 2019), was developed. The DPD·⁺ produced quantitatively by Fenton reaction was estimated using a spectrophotometer. In addition, the 7-hydroxycoumarin was detected using HPLC–DAD (320nm) with a C18 column and a gradient elution of water, methanol, and acetic acid (Killard et al., 1996).

Tarvin et al. (2010) reported methods for the analysis of H₂O₂, using HPLC–FLD and HPLC–electrochemical detection (ECD). An H₂SO₄ solution (1.00mM) with 0.10mM EDTA was used as the mobile phase in the HPLC–FLD method using an Acclaim 120 C-18 column. Whether addition of more acid to the mobile phase would affect the retention time or peak area was tested next; 1.00mM H₂SO₄ was found to show the greatest peak area, lowest %RSD of the peak area, and best peak symmetry for the H₂O₂ standard. H₂O₂ was eluted within 7min after the injection.

Method validation

A calibration curve was constructed with 6 dilutions of the H₂O₂ standard solution. Linearity was assessed in terms of regression of the calibration curve constructed. The regression of determination (R²) was 0.999 for HPLC–DAD method in the range of 0.5–100mg/L (14.71–2941.17μM) and 0.997 for HPLC–FLD method in the lower range of 5–400μg/L (0.15–11.76μM). Although the linear range was very narrow for HPLC–FLD method, it showed better LOD and LOQ than the HPLC–DAD method. Fenton reaction had been applied for the fluorometric determination of H₂O₂ in milk by Abbas et al. (2010). Their method presented linear responses between the fluorescence intensity and H₂O₂ concentration over a range of 20nM to 20μM. HPLC with fluorescence detection, based on the oxidation of p-hydroxyphenylacetic acid for H₂O₂ analysis, proposed by Tarvin et al. (2010), showed linearity over the range of 15–300μM.

Both LOD and LOQ of the analytical methods were determined by calculating the signal-to-noise ratios of 3 and 10, respectively. LOD and LOQ values were 0.30 and 0.91mg/L (8.82 and 26.76μM), respectively, for HPLC analysis using HPLC–DAD. For HPLC–FLD method, the values were much lower (0.001 and 0.003mg/L or 0.03 and 0.09μM, respectively).

In a study by Tarvin et al. (2010), two HPLC methods, namely HPLC–FLD (based on the oxidation of p-hydroxyphenylacetic acid) and HPLC–ECD, were developed to analyze H₂O₂. The LOD of H₂O₂ was reported to be 0.19μg/mL (6μM) by HPLC–FLD and 0.02μg/mL (0.6μM) by HPLC–ECD. Our HPLC–FLD method could detect much lower concentrations of H₂O₂ than those of Tarvin et al. (2010).

Repeatability represents intra-assay precision under the same operating conditions over a short interval of time (ICH Harmonised Tripartite, Guideline, 2005). Repeatability of HPLC–DAD and HPLC–FLD methods was expressed as %RSD. Accuracy represents the closeness of agreement between the values accepted as a reference value and the value obtained (ICH Harmonised Tripartite, Guideline, 2005). Recovery test was performed to evaluate the precision and accuracy of both the developed methods. Three food samples, namely marine products, dairy products, and other food, were fortified with three concentrations of H₂O₂ standard solution. Repeatability (%RSD) was observed in the range of 0.7 to 1.7 and 0.5 to 9.7 for the HPLC–DAD method and HPLC–FLD method, respectively (Table ​(Table2).2). Recovery test applying the HPLC–DAD method revealed a mean recovery rate of 94.3% for marine products, 88.4% for dairy products, and 90.6% for other food. In case of HPLC–FLD method, the mean recovery rates were estimated as 96.4%, 88.1%, and 84.4% for marine products, dairy products, and other food, respectively.

NIFDS (2003) studied the recovery of H₂O₂ in foods using HPLC–DAD. Results indicated the mean recovery rates to be 68.9% in dried seafood and 82.4% in beverages. Our study exhibited better recovery rates than a previous study performed by NIFDS (Table ​(Table2).2). Tarvin et al. (2010) had performed a recovery test for H₂O₂ by applying aliquots of 4.1mg of H₂O₂ to the surface of paint chips dried with a heat gun; the recoveries of H₂O₂ were in the range 89–150%. Hu et al. (2012) had developed a headspace gas chromatographic method for rapid determination of H₂O₂ in pulp bleaching effluents; the method demonstrated recovery ranging from 98 to 103%. The fluorometric determination of H₂O₂ in milk by Abbas et al. (2010) exhibited recoveries of H₂O₂ in the range of 93.8–106.3%, with the %RSD being less than 6.23%.

In titration methods officially used by many national institutions reproduced in our laboratory, the lowest concentration of H₂O₂ was 1,470µM and the low recovery was 20.9%, increasing from 8292µM to a maximum of 70% (data not shown). Compared to this conventional titration method our two new assays can reliably detect much lower concentrations with high reproducibility.

Verification with LC–MS/MS analysis

The vanadium(V)-peroxo complex detected in HPLC–DAD analysis could not be analyzed by LC–MS/MS, and its LC–MS analysis has not been reported previously. Contrary to the vanadium(V)-peroxo complex, the 7-hydroxycoumarin produced from Fenton reaction could be detected via LC–MS/MS analysis. The chemical formula of 7-hydroxycoumarin is C₉H₆O₃, and its precursor ion was detected as the deprotonated form (C₉H₅O₃⁻,161.1m/z) in negative ion mode. The extracted ion chromatogram (EIC) of 7-hydroxycoumarin is shown in Fig.2(C), and (D). In our study, the precursor ion of 7-hydroxycoumarin was found at 161.1m/z, detected at 3.37min. The product ions were observed at 73.08 and 133.01m/z in MS/MS spectrum. The product ion of 7-hydroxycoumarin, formed by the loss of CO, had been reported by Rodríguez-Medina et al. (2009). The product ion at 133m/z, observed in our study, would also be formed by the loss of CO. Tsamesidis et al. (2020) reported a precursor ion of 7-hydroxycoumarin that was detected in the deprotonated form [161.0244 (th)] in negative ion mode. In that study, an LC–MS analysis was performed using HPLC coupled with LTQ–Orbitrap XL ETD mass spectrometer. In other LC–ESI–MS conditions reported by Mercolini et al. (2013), a 7-hydroxycoumarin was observed as 163.1m/z in positive ion mode and its product ion was detected at 77.3m/z.

Sample analysis

Both HPLC–DAD and HPLC–FLD methods were applied to check the residual H₂O₂ in food samples. A total of 300 food samples (150 samples per each method)were collected from the Korean market over the period of 2016–2022, all of which were mainly classified as processed fishery products, milk products, or noodles. H₂O₂ was detected in 5 processed fishery products samples using the HPLC–DAD and HPLC-FLD analyses, as shown in Fig.3(A). The level of residual H₂O₂ was in the range of 15.4 to 258.1mg/kg, and the mean value was 72.96mg/kg (Table ​(Table3).3). The five samples with residual H₂O₂ were processed fishery products and the peaks in HPLC analysis were verified by LC–MS analysis. EIC and MS/MS spectra of the positive samples are shown in Fig.3(B). The precursor ion was found at 161m/z, and the product ions (73 and 133m/z) were verified via the MS/MS spectrum.

Detection of H₂O₂ residues in food items has been reported occasionally. Takahashi et al. (1999) had reported the presence of H₂O₂ (73.8μM) in instant coffee. Abbas et al. (2010) reported detecting trace amounts of H₂O₂ (mean, 0.41μM) in 4 milk samples using a fluorometric method. Su et al. (2001) reported that 8 noodle samples sourced from traditional markets in Taipei contained H₂O₂ residues at concentrations ranging from 50 to 1240ppm. Another study reported detecting residual H₂O₂ in fruit samples, such as banana, peach, orange, and strawberry (0.5–1.9ppm), and in vegetables, such as pepper, onion, cucumber, burdock, and egg plants (0.4–0.9ppm) (Lee et al., 2002). H₂O₂ concentrations detected in food samples in our study using both the HPLC methods were higher than those reported in other studies. Furthermore, residual H₂O₂ was detected in only processed fishery samples containing dried squid, which can be attributed to the use of H₂O₂ in the bleaching step. Therefore, managing the bleaching process during the processing fish products is necessary. In contrast, no residual H₂O₂ was detected when the same processed fish products were analyzed using the conventional titration method. These results imply that both the newly developed HPLC methods can detect residual H₂O₂ at concentrations unmeasurable by titration methods, and these methods will provide an academic basis for precise control of H₂O₂ contamination in the future.

Conflict of interest

The authors declare that they have no conflicts of interest.

Chemical compounds studied in this article Hydrogen peroxide (PubChem CID: 784), Ammonium metavanadate (PubChem CID: 516859), 7-Hydroxycoumarin (PubChem CID: 5281426), Coumarin (PubChem CID: 323), Ferrous sulfate (PubChem CID: 24393).

Publisher's Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

• Abbas M, Luo W, Zhu L, Zou J, Tang H. Fluorometric determination of hydrogen peroxide in milk by using a Fenton reaction system. Food Chemistry. 2010;120:327–331. doi:10.1016/j.foodchem.2009.10.024. [CrossRef] [Google Scholar]
• Alpat Ş, Alpat SK, Dursun Z, Telefoncu A. Development of a new biosensor for mediatorless voltammetric determination of hydrogen peroxide and its application in milk samples. Journal of Applied Electrochemistry. 2009;39:971–977. doi:10.1007/s10800-009-9776-7. [CrossRef] [Google Scholar]
• Bilotta JJ, Waye JD. The “snow white” sign. Gastrointestinal Endoscopy. 1989;35:428–430. doi:10.1016/S0016-5107(89)72849-2. [PubMed] [CrossRef] [Google Scholar]
• Bortolini O, Conte V. Vanadium (V) peroxocomplexes: Structure, chemistry and biological implications. Journal of Inorganic Biochemistry. 2005;99:1549–1557. doi:10.1016/j.jinorgbio.2005.04.003. [PubMed] [CrossRef] [Google Scholar]
• Burns RA, Schmidt SM. Portal venous gas emboli after accidental ingestion of concentrated hydrogen peroxide. The Journal of Emergency Medicine. 2013;45:345–347. doi:10.1016/j.jemermed.2013.02.001. [PubMed] [CrossRef] [Google Scholar]
• Code of Federal Regulations. Direct food substances affirmed as generally recognized as safe. Sec. 184.1366 Hydrogen peroxide. CFR – Code of Federal Regulations Title 21, 3, 21CFR184.1366. Available from: https://www.ecfr.gov/cgi-bin/text-idx?node=se21.3.184_11366&rgn=div8. Accessed June. 2, 2021.
• Farrokhnia M, Karimi S, Momeni S, Khalililaghab S. Colorimetric sensor assay for detection of hydrogen peroxide using green synthesis of silver chloride nanoparticles: Experimental and theoretical evidence. Sensors and Actuators B: Chemical. 2017;246:979–987. doi:10.1016/j.snb.2017.02.066. [CrossRef] [Google Scholar]
• Guan H, Zhu L, Zhou H, Tang H. Rapid probing of photocatalytic activity on titania-based self-cleaning materials using 7-hydroxycoumarin fluorescent probe. Analytica Chimica Acta. 2008;608:73–78. doi:10.1016/j.aca.2007.12.009. [PubMed] [CrossRef] [Google Scholar]
• Hendriksen SM, Menth NL, Westgard BC, Cole JB, Walter JW, Masters TC, Logue CJ. Hyperbaric oxygen therapy for the prevention of arterial gas embolism in food grade hydrogen peroxide ingestion. The American Journal of Emergency Medicine. 2017;35:809. doi:10.1016/j.ajem.2016.12.027. [PubMed] [CrossRef] [Google Scholar]
• Hu H-C, Jin H-J, Chai X-S. Rapid determination of hydrogen peroxide in pulp bleaching effluents by headspace gas chromatography. Journal of Chromatography A. 2012;1235:182–184. doi:10.1016/j.chroma.2012.02.069. [PubMed] [CrossRef] [Google Scholar]
• ICH Harmonised Tripartite Guideline. Validation of Analytical Procedures: Text and Methodology Q2(R1). Available from https://database.ich.org/sites/default/files/Q2%28R1%29%20Guideline.pdf. Accessed Jul. 27, 2022.
• Ishibashi K-I, Fujishima A, Watanabe T, Hashimoto K. Detection of active oxidative species in TiO₂ photocatalysis using the fluorescence technique. Electrochemistry Communications. 2000;2:207–210. doi:10.1016/S1388-2481(00)00006-0. [CrossRef] [Google Scholar]
• Ivanova AS, Merkuleva AD, Andreev SV, Sakharov KA. Method for determination of hydrogen peroxide in adulterated milk using high performance liquid chromatography. Food Chemistry. 2019;283:431–436. doi:10.1016/j.foodchem.2019.01.051. [PubMed] [CrossRef] [Google Scholar]
• JECFA. Evaluation of certain food additives: sixty-third report of the Joint FAO/WHO Expert Committee on Food Additives. World Health Organization (2005)
• Killard AJ, O'Kennedy R, Bogan DP. Analysis of the glucuronidation of 7-hydroxycoumarin by HPLC. Journal of Pharmaceutical and Biomedical Analysis. 1996;14:1585–1590. doi:10.1016/0731-7085(96)01801-8. [PubMed] [CrossRef] [Google Scholar]
• Kogularasu S, Govindasamy M, Chen S-M, Akilarasan M, Mani V. 3D graphene oxide-cobalt oxide polyhedrons for highly sensitive non-enzymatic electrochemical determination of hydrogen peroxide. Sensors and Actuators B: Chemical. 2017;253:773–783. doi:10.1016/j.snb.2017.06.172. [CrossRef] [Google Scholar]
• Lee T-S, Lee Y-J, Park J-S, Kwon Y-K, Hwang J-Y, Lee J-Y, Lee C-W. Studies on the determination method of hydrogen peroxide in foods. Korean Journal of Food Science and Technology. 2002;34:998–1001. [Google Scholar]
• Mercolini L, Mandrioli R, Ferranti A, Sorella V, Protti M, Epifano F, Curini M, Raggi MA. Quantitative evaluation of auraptene and umbelliferone, chemopreventive coumarins in citrus fruits, by HPLC-UV-FL-MS. Journal of Agricultural and Food Chemistry. 2013;61:1694–1701. doi:10.1021/jf303060b. [PubMed] [CrossRef] [Google Scholar]
• Ministry of Food and Drug Safety Regulation #2021-19. Food Additives Code. Available from: https://www.mfds.go.kr/eng/brd/m_15/view.do?seq=72436&srchFr=&srchTo=&srchWord=&srchTp=&itm_seq_1=0&itm_seq_2=0&multi_itm_seq=0&company_cd=&company_nm=&page=1. Accessed Jul. 28, 2022
• NIFDS, Establishment of analytical methods for hydrogen 524 peroxide and sodium hypochlorite in foods. National Institute of Food and Drug Safety Evaluation, Cheong-Ju, Korea. (2003)
• Özkan M. Degradation of anthocyanins in sour cherry and pomegranate juices by hydrogen peroxide in the presence of added ascorbic acid. Food Chemistry. 2002;78:499–504. doi:10.1016/S0308-8146(02)00165-6. [CrossRef] [Google Scholar]
• Papafragkou S, Gasparyan A, Batista R, Scott P. Treatment of portal venous gas embolism with hyperbaric oxygen after accidental ingestion of hydrogen peroxide: A case report and review of the literature. The Journal of Emergency Medicine. 2012;43:e21–e23. doi:10.1016/j.jemermed.2009.07.043. [PubMed] [CrossRef] [Google Scholar]
• Patella B, Inguanta R, Piazza S, Sunseri C. A nanostructured sensor of hydrogen peroxide. Sensors and Actuators B: Chemical. 2017;245:44–54. doi:10.1016/j.snb.2017.01.106. [CrossRef] [Google Scholar]
• Perkowski J, Jozwiak W, Kos L, Stajszczyk P. Application of Fenton’s reagent in detergent separation in highly concentrated water solutions. Fibres & Textiles in Eastern Europe. 2006;14:114–119. [Google Scholar]
• Rodríguez-Medina IC, Beltrán-Debón R, Molina VM, Alonso-Villaverde C, Joven J, Menéndez JA, Segura-Carretero A, Fernández-Gutiérrez A. Direct characterization of aqueous extract of Hibiscus sabdariffa using HPLC with diode array detection coupled to ESI and ion trap MS. Journal of Separation Science. 2009;32:3441–3448. doi:10.1002/jssc.200900298. [PubMed] [CrossRef] [Google Scholar]
• Shen C-L, Su L-X, Zang J-H, Li X-J, Lou Q, Shan C-X. Carbon nanodots as dual-mode nanosensors for selective detection of hydrogen peroxide. Nanoscale Research Letters. 2017;12:1–10. doi:10.1186/s11671-017-2214-6. [PMC free article] [PubMed] [CrossRef] [Google Scholar]
• Steinberg SM. High-performance liquid chromatography method for determination of hydrogen peroxide in aqueous solution and application to simulated Martian soil and related materials. Environmental Monitoring and Assessment. 2013;185:3749–3757. doi:10.1007/s10661-012-2825-4. [PubMed] [CrossRef] [Google Scholar]
• Su S-C, Chou S-S, Chang P-C, Hwang D-F. Identification of hydrogen peroxide as a causative agent in noodles implicated in food poisoning. Journal of Food and Drug Analysis. 2001;9:220–223. [Google Scholar]
• Takahashi A, Hashimoto K, Kumazawa S, Nakayama T. Determination of hydrogen peroxide by high-performance liquid chromatography with a cation-exchange resin gel column and electrochemical detector. Analytical Sciences. 1999;15:481–483. doi:10.2116/analsci.15.481. [CrossRef] [Google Scholar]
• Tarvin M, McCord B, Mount K, Sherlach K, Miller ML. Optimization of two methods for the analysis of hydrogen peroxide: high performance liquid chromatography with fluorescence detection and high performance liquid chromatography with electrochemical detection in direct current mode. Journal of Chromatography A. 2010;1217:7564–7572. doi:10.1016/j.chroma.2010.10.022. [PubMed] [CrossRef] [Google Scholar]
• Tsamesidis I, Egwu CO, Pério P, Augereau J-M, Benoit-Vical F, Reybier K. An LC–MS assay to measure superoxide radicals and hydrogen peroxide in the blood system. Metabolites. 2020;10:175. doi:10.3390/metabo10050175. [PMC free article] [PubMed] [CrossRef] [Google Scholar]
• Walsh LJ. Safety issues relating to the use of hydrogen peroxide in dentistry. Australian Dental Journal. 2000;45:257–269. doi:10.1111/j.1834-7819.2000.tb00261.x. [PubMed] [CrossRef] [Google Scholar]
• Zaribafan A, Haghbeen K, Fazli M, Akhondali A. Spectrophotometric method for hydrogen peroxide determination through oxidation of organic dyes. Environmental Studies of Persian Gulf. 2014;1:93–101. [Google Scholar]
• Zhang Q, Fu S, Li H, Liu Y. A novel method for the determination of hydrogen peroxide in bleaching effluents by spectroscopy. BioResources. 2013;8:3699–3705. doi:10.15376/biores.8.3.3699-3705. [CrossRef] [Google Scholar]
• Zou J, Cai H, Wang D, Xiao J, Zhou Z, Yuan B. Spectrophotometric determination of trace hydrogen peroxide via the oxidative coloration of DPD using a Fenton system. Chemosphere. 2019;224:646–652. doi:10.1016/j.chemosphere.2019.03.005. [PubMed] [CrossRef] [Google Scholar]