Photodegradation kinetics and byproducts identification of the Aflatoxin B₁ in aqueous medium by ultra‐performance liquid chromatography–quadrupole time‐of‐flight mass spectrometry

Abstract

A photodegradation study of Aflatoxin B(1) (AFB(1)) in water solution was performed under UV irradiation at different AFB(1) initial concentrations and UV irradiation intensities. The effect of UV intensity on the AFB(1) photodegradation ratio is dominative, when compared with AFB(1) initial concentration. The photodegradation of AFB(1) was proved to follow first-order reaction kinetics (R(2) > or = 0.99). Three photodegradation products, i.e. P(1) (C(17)H(14)O(7)), P(2) (C(16)H(14)O(6)) and P(3) (C(16)H(12)O(7)), were identified on the basis of low mass error and high matching property by ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF MS), and the degradation pathway was proposed. This study first reports the appearance of these photodegradation products and the proposed degradation pathway in aqueous media.

Degradation of aflatoxin B1 by low-temperature radio frequency plasma and degradation product elucidation

“…The structures of the UV degradation products of AFB 1 have been elucidated, and the toxicity of the degradation products has been examined by the AMES test. It was found that exposure to UV caused the loss of double bond in the terminal furan ring [21] and the degradation products completely lost the mutagenic activity [26]. In this study, all the five degradation products lost their double bond in the terminal furan ring and product A even completely lost the entire ring.…”

“…Exposure to Co 60 gamma ray resulted in more than 20 degradation products [27], and ozonolysis of AFB 1 in acetonitrile and water yielded a total of 13 and 6 products, respectively [28,29]. Meanwhile, UV irradiation could also degrade AFB 1 , but only three products were resolved [21]. By comparing with these reports, it could be seen that the degradation products of AFB 1 by low-temperature RF plasma have never been reported before, implying that the plasma possibly exerted its degradation effect through different ways or different free radicals.…”

“…It could be seen that the degradation of AFB 1 initiated by low-temperature RF plasma started with an addition reaction that occurred in the C(8)-C(9) bond, resulting in the formation of an intermediate with m/z 331 (C 17 H 15 O 7 ). This compound has been identified as a major degradation product of AFB 1 caused by exposure to UV [21] and Co 60 gamma ray [27]. Besides, it could also be seen that the addition of OH and H to double bonds was the major fragmentation pathway of AFB 1 , followed by the loss of carbon monoxide.…”

“…In addition, many other methods, including ozonation [14][15][16][17], ionization [18], gamma ray irradiation [19], UV irradiation [20,21], and pulsed light exposure [22], have been reported capable of effectively degrading AFB 1 in artificial systems or real foods. Meanwhile, the structures of some physical degradation products have been elucidated by several authors, and their safety was assessed as well by either the AMES test or based on the structure-toxicity relationship [20,[23][24][25].…”

Detection of Aflatoxin M1 in Pasteurized Canned Milk and Using of UV Radiation for Detoxification

“…UV irradiation has been discovered for many years as an effective physical method to destroy aflatoxins for its photosensitive property [15] .Rate of degradation was a function of the film thickness and depth of penetration of the rays when operating conditions were held constant [16]. Because aflatoxins are photosensitive [15], our aim was to study the detection of aflatoxin M1 and detoxification of it in milk using ultraviolet (UV) energy at different distance between UV source and milk and different volumes of milk at different times.…”