Soil heavy metal detector

1. Brief introduction of high-precision soil heavy metal detector:

The problem of soil heavy metal pollution is becoming increasingly serious, causing a large amount of heavy metals such as cadmium, copper, arsenic, chromium, mercury, iron, zinc, manganese, copper, nickel, aluminum, fluorine, titanium, and selenium in the soil cultivation layer. Accumulation has become one of the main environmental problems we are facing. Heavy metals in the soil enter the food chain by accumulating in crops, posing a serious threat to the health of humans and animals. The mining of non-ferrous metal mines, the discharge of industrial "three wastes", the accumulation of heavy metal wastes, sewage irrigation in agricultural production, and the irrational use of agricultural chemicals may cause harmful heavy metal elements to enter the soil directly or indirectly, resulting in serious excessive heavy metal content in soil, crops, fruits and vegetables, water quality, and aquatic products. However, the current heavy metal determination method is slow, the steps are cumbersome, and the instruments are expensive. Based on this situation, we have developed a rapid heavy metal determination method.

2. Test items:

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

3. 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).

4. Detection principle of soil heavy metal detector:

(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 ion forms. After adding relevant detection reagents, the color is developed. Within a certain concentration range, the depth of the solution color is proportional to the content of heavy metals, obeying the Lambert-Beer law. The content value is then 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. 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.

5. Functional features:

1. This instrument integrates various functions in one, and does not require users to equip accessories by themselves, and can be flexibly tested.

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

3. 6 detection channels (solid-state design), can quickly detect 6 samples at a time, greatly improve detection efficiency and reduce detection costs.

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

5. Built-in crop expert fertilization system, can calculate the recommended fertilizer amount for the target yield of more than 100 kinds of national agricultural economic crops, fruit trees, etc., and scientifically guide agricultural production based on fertilization formula. The results of soil testing and fertilization formula can be printed, and the printed content includes: crop type, fertilizer type, target yield, total demand, and recommended fertilization plan.

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

7. The instrument has a large built-in memory, which supports viewing all historical test records and transmitting all test data.

8. Equipped with a smart cloud agriculture platform, after the instrument is connected to the wireless network, the test data can be uploaded wirelessly selectively or in batches, which is convenient for users to conduct long-term data management and visual analysis.

9. The instrument also has a USB interface and an Ethernet interface, and the data can be copied out with a USB flash drive at any time.

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

11. Built-in plant nutrition diagnosis standard atlas, according to the pictures of nutritional deficiencies of various crops, leaf comparison is carried out to diagnose abundance and deficiency.

12. 4 wavelength professional test cold light source (red, blue, green, orange), the wavelength of the light source is stable, the light source has no temperature drift phenomenon when working continuously for a long time, the life span is up to 100,000 hours, the reproducibility is good, and the accuracy is high.

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

14. 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.

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

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

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

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

19. GPS function: can record longitude and latitude locations during field operations to meet the needs of special users.

20. Built-in low voltage prompt function, which can clearly indicate the power level during detection and avoid test data deviation. It also has power-off protection function, which automatically saves data when power is off to prevent data loss.

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

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

6. Technical parameters:

1. Power supply: AC 220±22V DC 12V+5V (built-in lithium battery can also be used as vehicle power supply)

2. Power: ≤5W

3. Range and resolution: 0.001-9999

4. Repeatability error: ≤0.03% (0.0003, 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

12. Display resolution: 1024*600

13. Earthquake resistance: IP65

14. Instrument size: 48×34.5×22cm

15. Net weight of host: 5.2kg

Product's Website：http://en.huoerd.com/trzjsjcy/1892.html