According to GB/T 4927, beer is a type of alcoholic beverage made primarily from malt and water, with hops added and fermented by yeast. Finished beer is composed of rich substances, including esters, alcohols, phenols, amino acids, etc. Among them, phenolic compounds play an important role in beer. Specifically, during the stages of production, transportation, storage, and use, phenolic substances may come into contact with chlorine containing water, containers, and air, undergo chemical reactions, and produce chlorinated phenolic substances with special flavors, causing beer to produce disinfectant, odor, and other odors, resulting in changes in beer taste; At the same time, chlorophenols themselves also have certain toxicity and are carcinogenic and teratogenic to humans [1]. Therefore, close monitoring of chlorophenols in beer throughout the entire process is crucial to ensure the quality and safety of beer.

Chlorophenol compounds are a class of phenol derivatives containing chlorine, including up to a dozen compounds depending on the position and number of substituents of the chlorine element on the benzene ring. The commonly detected chlorinated phenol compounds include o-chlorophenol, 2,4-dichlorophenol, 2,6-dichlorophenol, 2,4,6-trichlorophenol, and 2,3,4,6-tetrachlorophenol. The available analytical methods mainly include liquid chromatography [2,3] and liquid chromatography-mass spectrometry, gas chromatography, and gas chromatography-mass spectrometry. Due to the high polarity and difficulty in ionization of chlorophenols, when using gas chromatography and gas chromatography-mass spectrometry for analysis, it is generally necessary to derive the target compound during sample pretreatment, which makes the analysis difficult. Liquid chromatography and liquid chromatography-mass spectrometry are currently the main analytical techniques for chlorophenols, which simplify the sample pretreatment process, improve analysis efficiency, and achieve accurate qualitative and quantitative analysis.

There are currently no relevant literature reports on the determination of the five chlorophenols in beer by liquid chromatography. However, the traditional high-performance liquid chromatography (HPLC) method is generally used for the determination of chlorophenols, which has low separation efficiency and ability, and is not conducive to rapid analysis. This article uses Agilent 1290 II UHPLC combined with Poroshell 120 Bonus RP chromatographic column to develop a rapid analysis method for five chlorophenols, which can accurately separate the five chlorophenols in beer. After preliminary methodological validation, this method is suitable for accurately determining five chlorophenols in beer.