Mo Kaibin, Wei Chaoqun, Bai Mingyang, Long Xiangyang, Liu Xuezhen, Ding Huanzhong
Guangdong Key Laboratory for Veterinary Drug Development and Safety Evaluation, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China.
Front Vet Sci. 2024 Jul 23;11:1451904. doi: 10.3389/fvets.2024.1451904. eCollection 2024.
Dimetridazole (DMZ) is a broad-spectrum anti-anaerobic and antiprotozoal drug extensively used for the control of blackhead disease in poultry (especially turkeys). The presence of DMZ and its metabolites in animal food poses potential risks to human health. In this study, we developed a high-performance liquid chromatography tandem mass spectrometry (HPLC/MS-MS) method for the precise detection of DMZ and its metabolite 2-hydroxymethyl-1-methyl-5-nitroimidazole (HMMNI). Our results demonstrate a strong linear relationship (r > 0.99) between the concentrations of DMZ and HMMNI in tissues and egg within the range of 1~100 ng/g. The limits of detection (LOD) were determined to be 0.5 ng/g, with corresponding limits of quantification (LOQ) at 1.0 ng/g. Furthermore, average recoveries in tissues and egg fell within the range of 84.90% to 103.01%, with coefficients of variation below 15% for both intra-day and inter-day analyses. To investigate the residue elimination pattern of DMZ and HMMNI, diets containing 500 mg/kg DMZ were fed to healthy SanHuang chicken and Hy-line Gray laying hens for 10 consecutive days. The results indicated that the concentration of HMMNI consistently exceeded that of DMZ during the same period, in both broiler tissues and egg. Sebum showed the slowest elimination of DMZ and HMMNI, becoming undetectable after 168 h of withdrawal. In egg, residues of both substances peaked on the first day after drug withdrawal, followed by slow elimination with half-lives of 0.45 days for DMZ and 0.66 days for HMMNI. Based on these findings, WT1.4 software was used to calculate a withdrawal time of 11 days for broilers and an egg abandonment period of 14 days after withdrawal for laying hens, providing a scientific basis for the safe and rational use of DMZ in poultry farming.
二甲硝唑（DMZ）是一种广谱抗厌氧菌和抗原虫药物，广泛用于控制家禽（尤其是火鸡）的黑头病。动物食品中DMZ及其代谢物的存在对人类健康构成潜在风险。在本研究中，我们开发了一种高效液相色谱串联质谱法（HPLC/MS-MS），用于精确检测DMZ及其代谢物2-羟甲基-1-甲基-5-硝基咪唑（HMMNI）。我们的结果表明，在1~100 ng/g范围内，组织和鸡蛋中DMZ和HMMNI的浓度之间存在很强的线性关系（r＞0.99）。检测限（LOD）确定为0.5 ng/g，相应的定量限（LOQ）为1.0 ng/g。此外，组织和鸡蛋中的平均回收率在84.90%至103.01%之间，日内和日间分析的变异系数均低于15%。为了研究DMZ和HMMNI的残留消除模式，连续10天给健康的三黄鸡和海兰灰蛋鸡饲喂含500 mg/kg DMZ的日粮。结果表明，在同一时期，无论是肉鸡组织还是鸡蛋中，HMMNI的浓度始终超过DMZ。皮脂中DMZ和HMMNI的消除最慢，停药168小时后无法检测到。在鸡蛋中，两种物质的残留量在停药后的第一天达到峰值，随后缓慢消除，DMZ的半衰期为0.45天，HMMNI的半衰期为0.66天。基于这些发现，使用WT1.4软件计算出肉鸡的停药时间为11天，蛋鸡停药后的弃蛋期为14天，为家禽养殖中安全合理使用DMZ提供了科学依据。
