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Green Giant Research Technology Trading (Shanghai) Co., Ltd
ada@getc.com.cn
Room 609, 6th Floor, Hongmei Business Building, 8075 Humin Road, Xuhui District, Shanghai
How to determine the control effect of matrix effect?
To prove the accuracy of the test results in the detection of veterinary drug residues, it is necessary to verify the control effect of matrix effects through systematic methods, which can be explained through the following five dimensions:
1、 Methodology validation (core basis)
1. Selective verification
oUse at leastSix different sources of blank matrix (such as pig, chicken, and cow muscle) were used to detect the target substance and endogenous interferents, ensuring that the response value interference was less than 20% of the lower limit of quantification (LLOQ) response and less than 5% of the internal standard response.
oVerify metabolite conversion interference and cross reactivity with co administered drugs.
2. Recovery rate and precision
oLow, medium, and high concentrations of target veterinary drugs (covering the quantitative range) should be added to the blank matrix, and the recovery rate should reach80%-120%；
oWithin the batch/The relative standard deviation (RSD) of inter batch precision is ≤ 15%.
3. Quantification of matrix effects
ocomputational method：ME (%)=(substrate curve slope/solvent curve slope -1) × 100
§|ME | ≤ 20%: acceptable (weak effect)
§20%<| ME |<50%: Optimization required (moderate effect)
§|ME | ≥ 50%: Invalid method (strong effect)
oAt least verification is requiredConsistency of ME values for three different source matrices (such as pig liver, chicken, and milk).
2、 Matrix effect control technology
method |
Key Operating Points |
validation metrics |
Matrix matching calibration |
Prepare standard curves using the same type of blank matrix (such as using pig muscle matrix for detecting pork) |
The ME value is approaching 0, and the recovery rate meets the standard |
Isotope internal standard method |
Add deuterated internal standard (such asD³⁷-Chloramphenicol) compensates for fluctuations in ionization efficiency |
Internal standard recovery rateRSD≤5% |
Purification optimization |
Adopting a hybrid typeSPE column (such as C18+PSA) removes phospholipids/fatty acids; Dilute the sample to reduce matrix concentration |
ME reduced to within 20% |
key points: Electric spray ion source（ESI needs to extend the retention time to ≥ 3 minutes to avoid early co effluent interference.
3、 Stability and reproducibility
1. Sample stabilityVerify the target substance in the matrix extraction solution and storage conditions（-Stability at 80 ℃, deviation ≤ 15% 17;
2. System reproducibilityThe same sample is tested between different batches, instruments, and operators,RSD≤15%。
4、 Compliance comparison
·Using standard substances (such as national veterinary drug standards) for calibration to ensure the integrity of the traceability chain;
·Conduct confirmation experiments on positive samples (such asComparison of LC-MS/MS and Immunoassay Results.
Conclusion
The accuracy of the test results must meet the following requirements:
① ME value ≤ 20% and recovery rate 80% -120%;
② Consistent validation data for multiple matrices/concentrations;
③ The method complies with the requirements of the Guiding Principles for the Elimination of Veterinary Drug Residues.
If all the above conditions are met, it can be determined that the matrix effect is controlled and the results are accurate and reliable.