国产精品久久成人网站,在线乱码一卡二卡三卡,国产一区丝袜在线播放,中文字幕久无码免费久久

1. Preparation and preservation of samples
The sample preparation for veterinary drug residue detection, also known as sample pretreatment, mainly includes processes such as sample shredding, homogenization, mixing, centrifugation, filtration, and controlled degradation.
To avoid the degradation of drugs that may remain in the sample, the collected or prepared sample should generally be immediately frozen and stored below -20 ℃ to ensure that the sample does not deteriorate or be damaged.
2. Sample pretreatment
The main characteristics of veterinary drug residue detection and analysis are complex sample matrix, low drug content to be tested, and the need for tedious sample pretreatment processes.
The main purpose of sample pretreatment is to separate the drug to be tested from the sample matrix, remove interfering impurities from the sample, and convert the drug to a detectable form within the concentration range detectable by the instrument.
The pre-treatment process of animal drug residue detection samples mainly includes three steps: extraction, purification, and concentration. According to the presence status of the drug to be tested, it is sometimes necessary to perform enzymatic hydrolysis and other treatments on the sample before extraction. To adapt to instrument detection, it is sometimes necessary to perform derivatization and other treatments on the sample.
Please indicate the source when reprinting: www.kaidajj.com.cn