SN/T 5446-2022 in English

1. Pretreatment optimization

Using ultrasonic cleaner and 1% acetic acid solution for double extraction, the extraction efficiency of copper complex in complex matrix samples such as tomatoes reached more than 92%. The composite purification system of PSA and C18 can effectively remove pigments (purification rate> 85%) and lipid interferences.

2. Instrument parameter settings

The mass spectrometer uses 146.07/118.05 as the quantitative ion pair, and the signal-to-noise ratio is best when the collision energy is 22.28eV. The acetonitrile ratio is increased to 30% at 5 minutes in the chromatographic gradient program, which can shorten the analysis time to 10 minutes/sample.

1. Key points of quality control

• Standard solutions must be prepared and used immediately (valid for 3 weeks)
• Matrix matching standard curves must be made for each batch of samples
• Retention time deviations must be controlled within ±2.5%

2. Abnormal handling plan

When the recovery rate exceeds the range of 80-120%, check whether the centrifuge speed reaches 12000r/min, or replace the PSA adsorbent batch.