1、 Accurate positioning: the core technological fortress of source supervision

The agricultural and rural departments bear the responsibility of supervising the quality and safety of agricultural products, focusing on the agricultural production process and serving as a "gateway" for the full process supervision of food safety. The core mission of its food additive (and pesticide residue) testing laboratory is to supervise and standardize the use of agricultural inputs, identify source risks, and ensure the safety of primary agricultural products. Compared to testing in the market circulation process, the Agricultural and Rural Bureau laboratory focuses more on precise monitoring and law enforcement confirmation of pesticide residues and illegal additives in agricultural products, veterinary drug residues and prohibited compounds in livestock products, as well as heavy metal pollution caused by environmental migration in the production area. Therefore, its instrument and equipment configuration needs to have both rapid screening capability and legal confirmation capability, forming a clear, efficient and reliable detection technology system.

2、 Overview of Core Testing Tasks and Corresponding Instrument Configuration

The construction of laboratory testing capabilities should be closely centered around the following core tasks:

Detection of pesticide residues in agriculture and animal medicine: covering organophosphorus, organochlorine, pyrethroid, carbamate pesticides, as well as antibiotics, hormones, clenbuterol and other veterinary drugs.

Detection of illegal and abused additives: such as coloring agents, bleaching agents (such as white chips), preservatives (illegal use), clenbuterol (such as clenbuterol), etc.

Heavy metal pollution detection: mainly monitoring elements such as lead, cadmium, mercury, arsenic, chromium, etc. that cause pollution to the environment of agricultural product production areas.

Routine physical and chemical testing and rapid screening: used for on-site rapid investigation and initial screening of large quantities of samples.

The following will provide a detailed explanation of the key instruments and equipment that support the above tasks.

3、 Detailed description of core instruments and equipment

（1） Chromatography Mass Spectrometry System: The "Gold Standard" and Main Force for Confirming Analysis

This is the cornerstone of modern food safety testing laboratories, responsible for precise qualitative and quantitative analysis of the vast majority of agricultural and veterinary drug residues and organic additives.

Liquid chromatography tandem mass spectrometer:

Principles and Applications: High performance liquid chromatography separation, tandem mass spectrometry for highly selective and sensitive detection. Especially suitable for compounds with high polarity, difficult volatility, and thermal instability, it is currently the first choice and confirmation method for detecting antibiotics, clenbuterol, some pesticides, and their metabolites. Its multi reaction monitoring mode can effectively eliminate matrix interference, and the results are authoritative.

Laboratory positioning: Core verification equipment used for law enforcement spot checks, risk monitoring, dispute arbitration, and other scenarios that require the issuance of statutory reports.

Gas chromatography-mass spectrometer:

Principles and Applications: Gas Chromatography Separation, Mass Spectrometry Detection. I am particularly skilled in analyzing volatile and semi volatile organic compounds. It is the main instrument for detecting organophosphorus pesticides, organochlorine pesticides, some pyrethroid pesticides, some food additives (such as preservatives and antioxidants), and aroma components.

Laboratory positioning: Core validation equipment, complementary to LC-MS/MS capabilities, forming a complete technical platform for organic pollutant analysis.

（2） Spectral instruments: tools for heavy metal detection and rapid screening

Inductively Coupled Plasma Mass Spectrometer:

Principle and Application: Using high-temperature plasma to atomize and ionize the sample, and detecting it by mass spectrometry. It is currently the most powerful tool for multi-element trace heavy metal analysis, capable of rapidly determining dozens of elements simultaneously, with high sensitivity and a wide linear range.

Laboratory positioning: High end validation equipment suitable for precise monitoring and risk assessment of key heavy metal pollutants such as lead, cadmium, arsenic, mercury, etc. It is an ideal choice for heavy metal analysis of complex matrix samples (such as soil and aquatic products).

Atomic absorption spectrometer/atomic fluorescence spectrometer:

Principles and Applications: AAS (especially graphite furnace method) has high sensitivity for detecting specific single elements (such as cadmium and lead); AFS has unique advantages over elements such as mercury and arsenic. The technology is mature and the operating cost is relatively low compared to ICP-MS.

Laboratory positioning: Conventional confirmation equipment that can be used as a supplement to ICP-MS or independently for daily detection of key heavy metal projects.

UV visible spectrophotometer/fluorescence spectrophotometer:

Principle and Application: Quantitative analysis based on the absorption or emission fluorescence characteristics of substances towards specific wavelengths of light. Can be used to detect specific items such as nitrite, sulfur dioxide, formaldehyde, and some synthetic pigments. The method is classic, the equipment is popular, and the operation is simple.

Laboratory positioning: Conventional physical and chemical analysis equipment used for routine testing of certain additives and illegal additives specified in national standards.

（3） Preprocessing and rapid screening equipment: key steps to improve efficiency

Efficient sample pretreatment equipment:

Necessity: The accuracy of chromatography-mass spectrometry analysis results is highly dependent on sample pretreatment. The necessary equipment includes: high-speed homogenizer, high-speed centrifuge, nitrogen blower, vortex oscillator, solid phase extractor, QuEChERS automatic processing platform, etc. Especially SPE and QuEChERS devices, which can efficiently purify samples and enrich target substances, are key to ensuring the accuracy of complex agricultural product matrix detection.

Food Safety Rapid Detector:

Principles and Applications: Usually based on enzyme inhibition rate method (used for rapid screening of organophosphorus and carbamate pesticides), colloidal gold immunochromatography (used for rapid screening of specific veterinary drugs and toxins), spectrophotometry, etc. Can provide qualitative or semi quantitative results within minutes to tens of minutes.

Laboratory positioning: On site screening and initial screening tools. Suitable for rapid investigation of township grassroots stations, acquisition sites, and major event support, it can significantly improve regulatory coverage and problem sample discovery rate, providing targeted guidance for laboratory confirmation.

4、 Suggestions for laboratory grading configuration

Based on the size of the jurisdiction, regulatory tasks, and fiscal budget, it is recommended to allocate resources in a hierarchical manner

County level basic laboratory:

Core: Gas chromatograph (with ECD and FPD detectors), high-performance liquid chromatograph (with DAD and FLD detectors), atomic absorption spectrometer.

Supporting equipment: complete sample pretreatment equipment, UV spectrophotometer, various rapid detection instruments and fixtures.

Ability: Able to complete the national standard method testing for most conventional pesticides, additives, and heavy metals, as well as rapid screening.

City level/Key Area Comprehensive Laboratory:

Enhance at the county level by adding at least one gas chromatography-mass spectrometer and/or liquid chromatography-mass spectrometer, and upgrading to an inductively coupled plasma mass spectrometer.

Ability: Possess comprehensive verification and detection capabilities for agricultural and veterinary drug residues and illegal additives, capable of conducting unknown substance screening and non-standard method research, supporting risk monitoring and emergency response.

Provincial/Regional Central Laboratory:

Configuration: Multiple sets of LC-MS/MS and GC-MS, high-resolution mass spectrometer (such as Q-TOF), and ICP-MS should be available.

Ability: Possess strong abilities in unknown substance identification, non targeted screening, metabolomics analysis, and undertake tasks such as method development, standard setting, technical training, and regional review.

Conclusion

The equipment level of the Food Additive Testing Laboratory of the Agriculture and Rural Bureau directly determines its ability to curb food safety risks from the source. Building a three-dimensional detection system with chromatography-mass spectrometry technology as the core, atomic spectroscopy technology as the support, and rapid detection technology as the extension is a key technological guarantee for achieving equal emphasis on "production" and "management". With the development of precision agriculture and green agriculture, laboratories need to further evolve towards high throughput, intelligence, and informatization in the future. Through equipment upgrades and deep integration of data analysis, they will build a more robust and sensitive technological wall to safeguard the safety of the people's tongues and promote high-quality agricultural development.