LS/T 6152-2025 in English

Standard Development Background and Technological Evolution

LS/T 6152-2025, "Grain and Oil Inspection - Determination of T-2/HT-2 Toxins in Grains - Colloidal Gold Rapid Quantitative Method," is a key technical standard for mycotoxin testing in my country's grain industry. T-2 and HT-2 toxins, representatives of the trichothecenes family of mycotoxins, exhibit potent cytotoxic and immunosuppressive effects, posing a serious threat to food safety and human health. Traditional detection methods, such as liquid chromatography-mass spectrometry, while highly accurate, are expensive, complex, and require long testing cycles, making them inadequate for rapid on-site screening.

This standard, based on colloidal gold immunochromatography technology and combined with modern reader equipment, enables rapid, quantitative detection of T-2/HT-2 toxins. This technological evolution reflects the shift from precise laboratory analysis to rapid on-site testing, and from qualitative screening to quantitative determination, fully meeting the practical needs of grain quality and safety regulation.

Test Principle and Technical Features

The colloidal gold rapid quantitative method used in this standard is based on the principle of competitive immunochromatography. T-2/HT-2 toxin in the sample extract specifically binds to the colloidal gold-labeled antibody in the test strip. Changes in color intensity between the test and control lines establish a quantitative relationship between toxin content and color depth.

Requirements for key instruments and equipment

The standard puts forward clear technical requirements for the key instruments and equipment used in the testing process:

Pulverizer: After being crushed, all samples must pass through a 20-mesh sieve to ensure sample uniformity and representativeness.

Balance: Sensitivity 0.01g, ensure weighing accuracy, which directly affects extraction efficiency.

Oscillator: Frequency ≥2500 r/min, ensures sufficient toxin extraction.

Centrifuge: Speed ≥4000 r/min, for rapid separation of sample extracts.

T-2/HT-2 Toxin Colloidal Gold Rapid Quantitative Test Strips: Requires refrigerated storage (2°C-8°C), technical requirements meet the requirements of Appendix A.

Incubator: Incubate at a constant temperature of 45°C, with a temperature control accuracy of ±1°C, to ensure consistent reaction conditions.

Reader: A dedicated device that accurately measures the color intensity of the test strips and automatically calculates the results.

Sample preparation and measurement process

The sample preparation process is strictly carried out in accordance with the standard requirements to ensure the accuracy and reliability of the test results:

Special precautions during the assay: After removing the test strip from the refrigerator, return it to room temperature. The incubation temperature must be strictly controlled at 45°C for an exact 10 minutes. Reading should be completed within 2 minutes of the end of incubation to ensure the timeliness of the test results.

Analysis of Performance Evaluation Requirements

Appendix A proposes strict evaluation requirements for the performance of T-2/HT-2 toxin colloidal gold rapid quantitative detection strips:

These performance indicators ensure the reliability and stability of the detection method in practical applications, providing technical support for grain quality and safety supervision.

Practical Application Case Analysis

Taking wheat sample testing as an example, the practical application of the standard method is explained in detail: During incoming inspection, a grain storage enterprise discovered that some wheat samples were suspected of being moldy and adopted this standard method for rapid screening. Accurately weigh 10.00g of crushed sample, add 20mL of 70% methanol solution, extract by shaking, filter, take 100μL of filtrate and add 1mL of dilution buffer to mix. Use a preheated incubator to incubate at 45℃ for 10 minutes, and the reader shows the test result as 18.25μg/kg. The repeated measurement result is 17.89μg/kg, and the absolute difference is 0.36μg/kg, which is less than 15% of the arithmetic mean and meets the precision requirements.

This case demonstrates the advantages of this standard method in practical application: fast, simple, accurate, and able to complete the screening of a large number of samples in a short time, providing timely technical support for grain storage and quality supervision.

Recommendations for Standard Implementation

To ensure the effective implementation of the LS/T 6152-2025 standard, the following recommendations are made:

Equipment Configuration Recommendations: Testing institutions should be equipped with a full set of equipment that meets the requirements of the standard. In particular, readers and incubators must be calibrated regularly to ensure the accuracy of test results.

Personnel Training Requirements: Operators must undergo professional training and be proficient in key technical aspects such as sample preparation, test strip use, and reader operation.

Quality Control Measures: Establish a comprehensive quality control system, including regular verification using reference materials, participating in proficiency testing activities, and establishing test process records.

Test Strip Management: Strictly adhere to the storage conditions and usage requirements of test strips, establish an inventory management system, and ensure that test strips are used within their validity period.

Result confirmation mechanism: For test results close to the limit value, it is recommended to use the national standard method for confirmation to ensure the reliability of the test results.

The implementation of this standard will significantly enhance my country's ability to detect T-2/HT-2 toxins in grain, provide strong technical support for grain quality and safety supervision, and promote the healthy development of the grain industry.