Soil heavy metal rapid tester

Brief description:

The current heavy metal determination method is slow, the steps are complicated and the instruments are expensive. Based on this situation, we have developed a rapid heavy metal determination method.

Test items:

It can perform rapid joint determination of arsenic, lead, cadmium, chromium, mercury, nickel, aluminum, fluorine, titanium, selenium, iron, zinc, manganese, copper, etc. in samples such as soil, fertilizer, crops, vegetables, fruits, water quality, and food.

Detection speed:

The five tests of lead, arsenic, chromium, cadmium and mercury take about 60 minutes in total (including soil sample pretreatment and reagent preparation)

The single test of iron, zinc, manganese, copper and aluminum takes about 30 minutes (including soil sample pretreatment and reagent preparation)

Detection principle:

(i) After the sample is digested, all forms of heavy metals (including arsenic, lead, cadmium, chromium, mercury, nickel, aluminum, fluorine, titanium, selenium, iron, zinc, manganese, copper, etc.) are converted into ionic forms, and the color is developed after adding relevant detection reagents. Within a certain concentration range, the depth of the solution color is proportional to the content of heavy metals, obeying the Lambert-Beer law, and then the content value is measured by the instrument, and compared with the national standard for agricultural product safety quality and pollution-free vegetable safety requirements to determine the heavy metal content of vegetable samples.

(II) Detection principles and standards for various heavy metals

1. Detection principles and standards for heavy metal arsenic

The national standard (GB/T5009.11-2003) borohydride reduction colorimetric method is used, that is, after the sample is digested, potassium iodide-thiourea is added and heated to reduce pentavalent arsenic to trivalent arsenic. Under acidic conditions, potassium borohydride reduces trivalent arsenic to negative trivalent arsenic, forming arsenic hydrogen, which is introduced into the absorption liquid and turns yellow. The arsenic content is obtained by instrument detection.

2. Detection principles and standards for heavy metal lead

The national standard (GB/T5009.12-2003) disulfide hydrazone colorimetric method is used, that is, after the sample is digested, under weak alkaline conditions, lead ions and disulfide hydrazone form a red complex, which is dissolved in chloroform and then colorimetrically determined.

3. Detection principle and adoption standard of heavy metal chromium

After the sample is digested, in the presence of divalent manganese, chromium ions react with diphenylcarbazide to form a purple-red complex. The color depth of the complex is proportional to the hexavalent chromium content, and the chromium content can be obtained by colorimetric determination.

4. Detection principle and adoption standard of heavy metal cadmium

The national standard (GB/T5009.15-2003) colorimetric method is adopted, that is, after the sample is digested, under alkaline conditions, cadmium ions react with 6-bromobenzothiazole azonaphthol to form a red complex, which is dissolved in chloroform and then colorimetrically determined.

5. Detection principle and adoption standard of heavy metal mercury

The national standard (GB/T5009.17-2003) disulfide hydrazone colorimetric method is adopted, that is, after the sample is digested, under acidic conditions, mercury ions react with disulfide hydrazone to form an orange-red complex, which is dissolved in chloroform and then colorimetrically determined.

Features:

1. Android smart operating system, the main control chip uses ARM Cortex-A7, RK3288/4-core processor, main frequency 1.88Ghz, faster operation speed and stronger stability.

2. Adopting precision rotating colorimetric cell design, the consistency of light source is more accurate, ensuring detection accuracy.

3. 12 rotating detection channels, 12 samples can be quickly detected at one time, greatly improving detection efficiency and reducing detection costs.

4. Adopting high-precision filter technology independent patent analysis method (patent number: ZL 2018 2 1777724.7), authoritative certification.

5. Built-in calibration function during the detection process, intelligent constant current voltage regulation, automatic light intensity calibration to ensure detection accuracy.

6. The instrument is equipped with wifi wireless upload, 4G network transmission, GPRS wireless remote transmission, and fast data upload.

7. Equipped with a cloud platform, after the instrument is connected to the wireless network, the detection data can be selectively or batch wirelessly uploaded, which is convenient for users to conduct long-term data management and visual analysis.

8. The instrument is equipped with both USB and Ethernet interfaces, built-in large-capacity memory, and can copy data with a USB flash drive at any time.

9. You can use your mobile phone to log in to the cloud platform at any time to view historical data online

10. 4 wavelengths of professional testing cold light sources (red, blue, green, and orange), the wavelength of the light source is stable, the light source has no temperature drift for a long time, the life span is up to 100,000 hours, the reproducibility is good, and the accuracy is high.

11. The colorimetric cell uses a standard 1cm colorimetric dish, without mechanical displacement and wear, the optical path test positioning is accurate, and external light interference is effectively shielded, ensuring that the test results are better than the national standard requirements.

12. The instrument system is equipped with a sample pre-treatment operation video. Various sample detection methods can be viewed by clicking on the video module. The test personnel do not need to self-study the manual. The guidance and teaching are convenient and fast, which is convenient for novices to operate quickly.

13. Built-in new generation high-speed thermal printer (no ribbon required), the printed content includes: testing unit, testing personnel, testing items, channel number, absorbance, content (mg/kg), testing time, and QR code and other information

14. Highly sensitive 7-inch true color touch screen, adopts more efficient and humanized operation, high-definition and high-interactive display, greatly reducing the cumbersome operation and errors of traditional instruments.

15. Built-in clock function, convenient operation time recording, long-term historical tracing.

16. Multiple account passwords can be set to log in, efficient UI interactive interface, different users can freely add and edit test information, and can be used for a long time after saving.

17. GPS function: can record longitude and latitude locations during field operations to meet special user needs.

18. Built-in low voltage prompt function, can clarify the power during detection to avoid test data deviation, and has power-off protection function, automatically saves data when power is off to prevent data loss.

19. AC and DC dual-use power supply mode, built-in large-capacity rechargeable lithium battery, can work continuously for more than 10 hours when fully charged, and can be connected to an external vehicle power supply for storage.

20. The instrument has the function of switching between Chinese and English, which can meet export requirements.

21. High-strength PVC engineering plastic suitcase design, durable and easy to carry.

Technical parameters:

1. Power supply: AC 220±22V DC 12V+5V (the instrument has built-in lithium battery and can also use vehicle power supply)

2. Power: ≤5W

3. Range and resolution: 0.001-9999

4. Repeatability error: ≤0.02% (0.0002, potassium dichromate solution)

5. Instrument stability: No digital drift within one hour (transmittance measurement); digital drift within two hours does not exceed 0.3% (0.003, transmittance measurement), 0.001 (absorbance measurement).

6. Linear error: ≤0.1% (0.001, copper sulfate detection)

7. Sensitivity: red light ≥4.5 ×10-5 blue light ≥3.17×10-3 green light ≥2.35×10-3 orange light ≥2.13×10-3

8. Wavelength range: red light: 680±2nm; blue light: 420±2nm; green light: 510±2nm; orange light: 590±4nm

9. Display resolution: 1024*600

10. Anti-seismic level: IP65

11. Instrument size: 48×34.5×22cm

12. Main unit net weight: 5.2kg