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Shanghai Shang Shaft Bearing Quality Inspection Institute Co., Ltd.

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Address: 301 Shangxue Road, Jiading District, Shanghai

How to do method validation

2020-12-29 09:46

4.5.14 Selection, verification and validation of methods 

The inspection and testing organization shall establish and maintain control procedures for inspection and testing methods. Inspection and testing methods include standard methods and non-standard methods (including self-made methods). Priority should be given to using standard methods and ensuring that a valid version of the standard is used. Before using the standard method, it should be confirmed. Before using non-standard methods (including self-made methods), should be confirmed. The inspection and testing institution shall track the change of the method and confirm or confirm it again. When necessary, the inspection and testing institution shall formulate operation instructions. If the method deviation is really required, it should be documented, subject to technical judgment and approval, and with the consent of the customer. The customer should be notified when the method suggested by the customer is not suitable or has expired.

The use of non-standard methods (including self-made methods) should obtain the customer's prior consent and inform the customer of the possible risks of the relevant methods. When necessary, the inspection and testing agency shall establish and maintain control procedures for the development of self-made methods, which shall be confirmed.


Interpretation of provisions

1, the organization should establish and maintain inspection and testing methods control procedures. The institution shall use appropriate methods (including sampling methods) for inspection and testing, which shall meet the needs of the customer and shall be the method by which the institution obtains the qualification approval.

2, inspection and testing methods include standard methods and non-standard methods, non-standard methods include self-made methods.

3. When the method specified by the customer is the method of the enterprise, it cannot be directly used as the method of qualification certification. Only after the organization has converted to its own method and confirmed, can it apply for qualification certification.

4. Before the organization uses the standard methods for the first time, it should prove that it can correctly apply these standard methods. If the standard method is changed, it should be confirmed again and relevant supporting materials should be provided.

5. Institutions should confirm before using non-standard methods to ensure that the method is suitable for the intended use and provide relevant supporting materials. If the method is changed, it should be confirmed again and relevant supporting materials should be provided.

6. If standards, specifications and methods cannot be directly used by operators, or the contents are not easy to understand, the provisions are not concise enough or lack sufficient information, or there are optional steps in the methods, which will vary from person to person when applying the methods and may affect the correctness of inspection data and results, operation instructions (including detailed rules or supplementary documents) shall be formulated.

7, deviation refers to a certain allowable range, a certain number and a certain period of time under the conditions of written permission. The agency should establish a documented provision that allows for deviations from the methodology. Non-standard methods should not be treated as method deviations.

8. When the method suggested by the customer is not suitable or has expired, the customer should be notified. If the client insists on using a method that is not suitable or has expired, the institution shall explain it in the entrustment contract and the result report, and shall clarify the qualification of the method in the result report.

9. The organization shall formulate procedures to standardize the design and development, resource allocation, personnel, responsibilities and authority, input and output of the inspection and testing methods formulated by itself. The methods formulated by itself must be used after confirmation. In the process of method development, regular reviews are required to verify that the customer's needs can be met. When using self-made methods to complete customer tasks, it is necessary to obtain the customer's consent in advance and inform the customer of possible risks.


Key points of method review

The focus of the method review is on the applicability and proper implementation of the method. The first step in the review should be to distinguish between standard and non-standard methods.

For standard methods, the review should review the effectiveness of the method verification. It is mainly required that before introducing standard methods, inspection and testing institutions should prove that they have the ability to meet the requirements of standard methods in carrying out inspection and testing activities from the aspects of "people", "machine", "material", "method", "ring" and "test". For non-standard methods, the validation of the method, the validity of the validation and whether it can be implemented correctly should be reviewed.

Object confirmed by the method

Non-standard, out-of-scope use of standard methods, methods developed by other laboratories, expanded and modified standard methods


How to confirm the method

(1) Determine the analysis requirements: investigate the problems to be solved by the customer, investigate the reasons for the analysis, find out the purpose that the customer hopes to achieve through the analysis work, and judge which performance parameters of the method are related to the work and which target values are necessary;(2) design a set of experiments;(3) conduct experiments;(4) use data to evaluate applicability;(5) make confirmation instructions, it is a positive affirmation of the applicability of the method;(6) It can also be more widely confirmed within the scope of the method study to illustrate the applicability of the method to various substrate types, analytes, concentration levels, precision and accuracy.



What are the performance parameters of the method

(1) Identity confirmation (selectivity/specificity);(2) Accuracy (deviation, recovery) is important for calculating the absolute value of analytes or characteristics;(3) Precision (repeatability, reproducibility) is very important in level ratio research;(4) Working range is very important in most cases;(5) Durability/anti-interference, which can indicate which parameters to control, in order to maintain the performance of the method;(6) sensitivity, medical and clinical chemists use it as a parameter that can replace the detection limit.

What are the tools for method validation (not limited to the following):(1) Use reference standards or reference materials (reference materials) for testing;(2) Compare results with other methods;(3) Interlaboratory comparison;(4) Systematic review of factors affecting results;(5) Based on scientific understanding of the theoretical principles and practical experience of the method, an assessment of the uncertainty of the results obtained.