In feed testing, the detection data of liquid chromatography is directly used as the basis for feed safety judgment. The standardization of its calibration and the timeliness of its maintenance are key to ensuring accurate data and extending equipment life. The feed matrix is complex and the detection indicators are mostly trace components,Feed detection liquid chromatographyEasy to be contaminated and prone to performance drift, it is necessary to establish a systematic calibration and maintenance system that is compatible with laboratory quality control standards such as GB/T 27404.

Calibration should focus on core performance indicators and conduct precise verification on a periodic basis. Calibration of detection accuracy is the core, and it is necessary to use standard substances (such as aflatoxin B1 standard) for linear verification every month to ensure that the correlation coefficient R ² is ≥ 0.999, and the detection limit and quantification limit meet the requirements of the national standard for feed testing. Flow accuracy calibration is conducted quarterly, using soap film flow meters to measure the flow rate of the infusion system. The error should be controlled within ± 1% to avoid retention time deviation caused by flow drift. Calibration of detectors requires different types of operations: UV detectors are calibrated for absorbance accuracy every six months using potassium dichromate solution, while fluorescence detectors are calibrated for sensitivity using anthraquinone standards to ensure stable response values. In addition, it is necessary to invite third-party organizations to conduct comprehensive calibration every year and issue calibration certificates to meet the requirements of laboratory qualification certification.

Daily maintenance should be based on the pollution characteristics of feed testing, and key components should be cleaned and protected. The chromatographic column is a key maintenance point, and it needs to be rinsed with methanol water (1:1) for 30 minutes after each test. After detecting high-fat feed samples, it needs to be rinsed with isopropanol first to avoid blocking the stationary phase; When not in use for a long time, pure methanol should be injected and sealed. If the column pressure rises abnormally, the protective column should be replaced in a timely manner. The injection system is susceptible to contamination by feed matrix. After each injection, rinse the injection needle and sample ring with mobile phase. Disassemble the injection valve and clean the rotor sealing gasket weekly to prevent cross contamination.

The maintenance of infusion and detection systems needs to take into account both details and cycles. The sealing ring of the infusion pump should be replaced every six months to avoid leakage of the mobile phase; The filter needs to be disassembled and cleaned monthly to prevent particle blockage. The circulation pool of the detector needs to be regularly soaked in dilute nitric acid (5%) to remove residual metal ions. When detecting fluorescent detectors, it is necessary to avoid direct sunlight on the photomultiplier tube. In addition, the laboratory needs to maintain a constant temperature (20-25 ℃) and humidity (40% -60%) environment to avoid temperature fluctuations affecting pump accuracy and detector response.

Fault warning and record management are important aspects of maintenance. Establish a device operation log to record in detail the sample type, flow matching ratio, and column pressure changes detected each time. When the column pressure suddenly increases by more than 10% or the retention time deviation exceeds 0.5 minutes, immediately stop the machine for troubleshooting. In common faults, baseline drift is often caused by impure mobile phase or detector contamination, requiring replacement of chromatographic reagents and cleaning of the flow cell; Peak shaped tailing may indicate column failure and require column efficiency testing or replacement with a new column.

　　Feed detection liquid chromatographyCalibration and maintenance require precise calibration and adherence to standards, as well as meticulous maintenance to prevent malfunctions. By establishing a full process system of "regular calibration+daily cleaning+periodic replacement+fault tracing", it can ensure the reliability of detection data for drug residues, toxins and other indicators in feed, and control the annual failure rate of equipment within 5%, providing stable support for feed safety testing.