Antibiotic-resistant bacteria have become a serious problem worldwide, caused in part by the excessive use and discharge of antibiotics into the environment. Ampicillin (ABPC) is a widely used antibiotic. However, this chemical rapidly decomposes in water containing divalent cations like Ca2+ and Mg2+, thus, detection of ABPC in environmental water is difficult. This study was carried out to evaluate the presence of 2-hydroxy-3-phenylpyrazine (HPP), one of the degradation products of ABPC and β-lactam antibiotics with an ABPC substructure, in environmental water. An analytical method for HPP monitoring in environmental water was developed using liquid chromatography/tandem mass spectrometry. The analyte was extracted from water samples and enriched using a solid-phase extraction cartridge. The quantification limit was 1 ng L-1. The HPP recovery rates from spiked water samples of 25 and 125 ng L-1 were 84.1 and 86.1%, respectively. The method was then used to determine HPP residue levels in 98 environmental water samples from rivers, household ponds, and aquacultural ponds in Vietnam. HPP residues were detected in 60 samples. The HPP detection rates in rivers and household ponds were 42 and 79%, respectively. HPP was not detected in aquacultural ponds. HPP residue concentrations in the samples ranged from 1.3 to 413.3 ng L-1. The residue levels in rivers flowing through city centres were higher than levels in other sampling locations. The findings of this study suggest that HPP is a promising marker for assessing the discharge of ABPC and β-lactam antibiotics with an ABPC substructure into the environment around sampling sites.

中文翻译：

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越南环境水中的2-羟基-3-苯基吡嗪（某些β-内酰胺抗生素的降解产物）的残留量。

耐药性细菌已成为全球范围内的严重问题，部分原因是抗生素的过度使用和向环境中的排放。氨苄西林（ABPC）是一种广泛使用的抗生素。但是，这种化学物质在含有二价阳离子如Ca2 +和Mg2 +的水中会迅速分解，因此很难检测环境水中的ABPC。这项研究旨在评估环境水中是否存在2-羟基-3-苯基吡嗪（HPP），这是ABPC和具有ABPC亚结构的β-内酰胺抗生素的降解产物之一。开发了一种使用液相色谱/串联质谱法监测环境水中HPP的分析方法。从水样品中提取分析物，并使用固相萃取柱进行富集。定量限为1 ng L-1。从25和125 ng L-1的加标水样品中的HPP回收率分别为84.1％和86.1％。然后，该方法用于测定越南河流，家庭池塘和水产养殖池塘的98种环境水样品中的HPP残留水平。在60个样品中检测到HPP残留。河流和家庭池塘中HPP的检出率分别为42％和79％。在水产养殖池塘中未检测到HPP。样品中HPP残留浓度的范围为1.3到413.3 ng L-1。流经市中心的河流中的残留水平高于其他采样地点的水平。这项研究的发现表明，HPP是评估ABPC和带有ABPC亚结构的β-内酰胺类抗生素向采样点周围环境的排放的有前途的标志物。