Which testing instruments are better, domestic or imported? أداة الاختبار –

Which testing instruments are better, domestic or imported?

In this announcement, five experts on government procurement of imported products gave the following opinions. They not only introduced the use of purchased instruments, but also carried out a detailed comparison of the differences between domestic and imported products.
　
　 (1) The liquid chromatograph that Mianyang Municipal Public Security Bureau plans to purchase is mainly used for the detection of pesticides, drugs and other articles in criminal cases.

Buyer requirements: The flow accuracy of the infusion pump is ≤±1%, the flow accuracy is ≤0.072% RSD, and the detector uses a UV detector. Among them, the solvent delivery system (pump) of liquid chromatography is the core component of liquid chromatography. Its stability directly affects repeatability and precisiontest results. The above index requirements can ensure that the infusion pump provides sufficient pre-column, safe and accurate. To control the flow rate of the mobile phase, the purchasing requirements are reasonable. The diode array detector has extraordinary sensitivity across the full spectrum range from ultraviolet to visible light and is extremely easy to use. It is the most developed and versatile detector for liquid chromatography. Since this unit is an important national statutory testing technology institution in Mianyang City, it is expected to provide strong technical support for complex substances in criminal cases. Equipping such detectors can improve detection efficiency and better adapt to the increasing detection requirements of government surveillance. In summary, the above index requirements meet the actual needs of work et the buyer\'s purchasing needs are reasonable.
　
At present, there is an obvious gap between domestic equipment and imported products in the following aspects: 1. The flow accuracy of the infusion pump of imported products can reach ±1 %, while the infusion pump flow accuracy of imported products can reach ±1%.equipment is generally 2.0%-4.0%; 2. The flow accuracy of imported products can reach ≤0.072% RSD, while domestic equipment is generally 0.1%; 3. The maximum working pressure of imported product pumps can reach 60Mpa, while domestic equipment is generally around 40Mpa; 5. Collection of UV detector data from imported equipment. The frequency can reach 80 Hz and the baseline noise can be <2.5 AU/cm. The data collection frequency of home equipment is generally around 70 Hz and the brThe basic rate is generally 10 AU/cm. Therefore, imported products fully meet the actual needs of buyers, while domestic products currently cannot fully meet the technical requirements of public procurement.
　
　 (2) The gas chromatograph to be purchased by Mianyang Public Security Bureau is mainly used for quantitative analysis of drugs.

Buyer Requirements: 1. Electronic gas flow/pressure control accuracy can reach 0.001 psi; 2. Reproducibility of retention time <0.008%; 3. FID detector acquisition rate: 500 Hz; 4. Minimum detection limit of ECD detector: <4.4fg/mL Lindane; 5. It has an air pressure sensor that can compensate for changes in altitude or ambient temperature. Effect on gas line pressure. Since this unit is an important national institution statusIn addition to testing technology, it must provide strong technical support for drug testing work. In order to better adapt to the constantly improving testing requirements, the above index requirements can meet its actual working needs and the buyer\'s purchasing needs. is reasonable.
　
At present: 1. The pressure control accuracy of imported products can reach 0.001 psi, while the pressure control accuracy of domestic products can only reach 0.1-0 .01 psi; 2. The retention time reproducibility of imported equipment is <0.008%. Household equipment generally does not have this indicator description; 3. Collection rate of FID detector: 500Hz, the collection rate of FID detector for home equipment is generally less than 300Hz; 4. Minimum ECD detection limit of imported products: <4.4fg/mL lindane, while domestic products are generalement <40fg/mL lindane; 5. Imported products have an atmospheric pressure sensor, which can compensate for the impact of changes in altitude or ambient temperature on gas line pressure and improve the reproducibility of chromatographic analysis, unlike domestic products .
　
　 (3) Mianyang Municipal Public Security Bureau plans to purchase a triple quadrupole GC-MS instrument, mainly used for qualitative and quantitative analysis of drugs.
　
In the current situation, due to the complex matrix and low detection limit in the analysis of drug metabolites in tissues and urine, the sensitivity of quadrupole mass spectrometry single-stage cannot meet the requirements, mainly quadrupole mass spectrometry. Mass spectrometry cannot effectively eliminate matrix interference, so the sensitivity cannot be pIf this is achieved, some components may be missed, or false positives may occur. In addition, due to the large amount of samples to be analyzed and the variety of target analysis components, single quadrupole mass spectrometry cannot meet the needs of high-throughput analysis. Triple quadrupole mass spectrometry, focusing on the detection of target substances, can completely solve these problems. The triple quadrupole GC-MS instrument has high sensitivity and can effectively eliminate matrix interference through secondary mass spectrometry and eliminate false positives in test results, thereby ensuring the reliability of analysis results. This instrument is currently a necessary instrument for high-throughput testing in most industrial testing laboratories for qualitative and quantitative analysis and research, and has a high utilization rate. As an important lMianyang City Government Laboratory, the buyer is responsible for the city\'s drug detection and analysis tasks. It is urgently necessary to equip it with this equipment, and the purchase request is reasonable.
　
At present, domestic equipment cannot meet the requirements of detection reproducibility, reliability, detection sensitivity and durability. This is mainly reflected in the following aspects: 1. In terms of gas chromatography, the gas circuit of imported products The pressure control accuracy can reach 0.001 psi, while the pressure accuracy of domestic products can only reach than 0.1-0.01 psi. The precision of high pressure control can guarantee better retention time reproducibility. Domestic equipment cannot currently offer better reproducibility; 2. Sensitivity of imported products: 1fg OFNfull scan S/N ≥5000:1, while the sensitivity of domestic products is generally 800:1. When analyzing complex array traces, the sensitivity cannot meet the detection requirements; 3. Imported productsThe maximum scanning rate can reach 500MRM/s, which cannot be achieved by domestic products. Because the faster the scanning speed, the higher the number of scans per unit time, the collected data information is rich enough, and at the same time, it can meet the requirements of narrow peak shapes in the analysis on capillary gas chromatography column. If data collection is insufficient, it may affect the chromatogram or total ion quantification. Therefore, domestic products cannot meet the buyer\'s working requirements in terms of instrument stability, sensitivity, detection limit, reproductibility, etc., while imported products can meet buyer\'s working requirements.

As we all know, foreign companies are commendable in terms of the quality of their products and services. Domestic instrumentation companies can only speak with their strength, work hard on product quality and service systems, and strictly control technical details. control, thereby paving the way for favorable opportunities for the domestic instrument procurement market.

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