The impact of the various chemical and physical factors on the degradation rate of bronopol

A rapid method for detecting bronopol in fresh fish, shrimp, crab, and shellfish samples using liquid chromatography-tandem mass spectrometry

Fish farming plays a vital role in providing food, nutrition, and employment globally. However, this industry faces security challenges, necessitating the use of fungicides and preservatives, such as bronopol, to increase product yields. Bronopol (2‑bromo-2-nitropropan-1,3-diol; CAS:52-51-7) is widely used in various fields, including food production, cosmetics, and, more recently, aquaculture. Currently, there is a limited number of techniques available for detecting bronopol in aquaculture products. This is primarily due to bronopol's instability, susceptibility to degradation, and tendency to form precipitates that pose challenges in extraction from aquaculture products. For this issue, this study presents a comprehensive method for detecting bronopol content in aquaculture tissues using liquid chromatography-tandem mass spectrometry (LC‒MS/MS). The methodology was optimized, involving extraction with Cu-Zn precipitant, cleanup using a small HLB column, separation on a T3 column, and gradient elution with water and acetonitrile mobile phases. The quantitative approach was employed without the use of an internal standard, following the external standard method. The spiked recoveries at 3 fortification levels (0.1, 0.2, and 1 mg/kg) ranged from 87.1 % to 108.1 % with relative standard deviations RSD ≤ 9.0 %. By applying this method to fresh fish, shrimp, crab, and shellfish samples from a local supermarket, no residues of bronopol were detected, ensuring the reliability of the results. The simplicity, rapidity, and high sensitivity of the method make it a suitable alternative to conventional techniques for bronopol detection. Moreover, the successful validation of the method's recovery and precision supports its potential application in monitoring and preventing the misuse of bronopol in aquaculture, thereby safeguarding aquaculture product quality and protecting public health.

Development and validation of an analytical method for determination of bronopol and kathon preservative in milk

The bronopol and kathon are chemical preservative which prevent degradation of milk samples and maintain authenticity in analysis. The detection is based on HPLC-UV-Vis spectroscopy, in which C₁₈ column (250 mm × 4.6 mm, 5 µm) was used for chromatographic separations, with a mobile phase comprising 0.1% phosphoric acid in water: Methanol: 0.1% phosphoric acid in acetonitrile (80:10:10) at a flow rate 0.8 ml/min at ambient temperature and with the UV detection at 250 nm for bronopol and 274 nm for kathon. The retention time of bronopol, kathon (MI 2-methyl-4-isothiazolin-3-one) and kathon (CMI 5-chloro-2-methyl-4-isothiazolin-3-one) was 4.52 min, 3.98 min and 6.68 min respectively with a total run time of 10 min. The linearity of the method was satisfactory with regression coefficient (R²) = 0.99. The limit of quantification was 72, 240, 390 mg L^-1 for bronopol, kathon (MI) and kathon (CMI) respectively. Five spiked levels (62.5, 125, 250, 500 and 1000 mg L^-1) were used to determine the recovery of bronopol, kathon (MI) and kathon (CMI) which was found to be 95.41 ± 11.84, 95.75 ± 8.21 and 92.22 ± 14.64% respectively, with relative standard deviations in the range 5.9-14.6%. The standardized analytical method was successfully used to rapidly detect bronopol and kathon in milk samples.

Electrocoagulation: Simply a Phase Separation Technology? The Case of Bronopol Compared to Its Treatment by EAOPs

Electrocoagulation (EC) has long been considered a phase separation process, well suited for industrial wastewater treatment since it causes a quick, drastic decay of organic matter content. This research demonstrates that EC also behaves, at least for some molecules like the industrial preservative bronopol, as an effective transformation technology able to yield several breakdown products. This finding has relevant environmental implications, pointing to EC as a greener process than described in literature. A thorough optimization of EC was performed with solutions of bronopol in a simulated water matrix, yielding the complete disappearance of the parent molecule within 20 min at 200 mA (∼20 mA/cm(2)), using Fe as the anode and cathode. A 25% of total organic carbon (TOC) abatement was attained as maximum, with bronopol being converted into bromonitromethane, bromochloromethane, formaldehyde and formic acid. N atoms were accumulated as NO3(-), whereas Br(-) was stable once released. This suggests that mediated oxidation by active chlorine, as well as by hydroxyl radicals resulting from its reaction with iron ions, is the main transformation mechanism. Aiming to enhance the mineralization, a sequential combination of EC with electro-Fenton (EF) as post-treatment process was proposed. EF with boron-doped diamond (BDD) anode ensured the gradual TOC removal under the action of (•)OH and BDD((•)OH), also transforming Br(-) into BrO3(-).