Soil heavy metal detector

Overview:

The problem of heavy metal pollution in soil is becoming increasingly serious, causing a large accumulation of heavy metals such as cadmium, copper, arsenic, chromium, mercury, iron, zinc, manganese, copper, nickel, aluminum, fluorine, titanium, selenium, etc. in the soil cultivation layer, which has become one of the main environmental problems currently faced. Heavy metals in soil accumulate in crops and enter the food chain, posing a serious threat to human and animal health. The mining of non-ferrous metal mines, the discharge of industrial “three wastes”, the accumulation of heavy metal waste, sewage irrigation in agricultural production, and the unreasonable use of agricultural chemicals may all lead to the direct or indirect entry of harmful heavy metal elements into the soil, resulting in serious excessive heavy metal content in soil, crops, fruits and vegetables, water quality, aquatic products, and other heavy metals. However, the current heavy metal determination methods have slow measurement speed, cumbersome steps, and expensive instruments. Based on this situation, we have developed a rapid determination method for heavy metals.

Testing items:

It can quickly and jointly determine arsenic, lead, cadmium, chromium, mercury, nickel, aluminum, fluorine, titanium, selenium, iron, aluminum, zinc, manganese, copper, etc. in samples such as soil, fertilizers, crops, vegetables, fruits, water quality, and food.

Detection speed:

About 60 minutes for lead, arsenic, chromium, cadmium, mercury, and five other tests (including soil sample pretreatment and reagent preparation)

Single detection of iron, zinc, manganese, copper, and aluminum for about 30 minutes (including soil sample pretreatment and reagent preparation)

Detection principle:

（1） After digestion of the sample, 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. 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, following the Lambert Beer law. The content value is then determined through instrument measurement, and compared with the national standard for agricultural product safety quality, pollution-free vegetable safety requirements, and allowable limit standards to determine the heavy metal content of vegetable samples.

（2） The detection principles and standards for various heavy metals

1. The detection principle and adopted standards of heavy metal arsenic

The national standard (GB/T5009.11-2003) borohydride reduction colorimetric method is adopted. After digestion of the sample, 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, forming arsine that is introduced into the absorption solution and turns yellow. The arsenic content is detected by the instrument.

2. The detection principle and standards for heavy metal lead

The national standard (GB/T5009.12-2003) dithizone colorimetric method is adopted, which means that after digestion of the sample, under weak alkaline conditions, lead ions and dithizone form a red complex, which is dissolved in trichloromethane and then determined by colorimetry.

3. The detection principle and adopted standards of heavy metal chromium

After digestion, in the presence of divalent manganese, chromium ions react with diphenylcarbazide to form a purple red complex. The color of the complex is directly proportional to the content of hexavalent chromium, and colorimetric determination can determine the chromium content.

4. The detection principle and adopted standards of heavy metal cadmium

The national standard (GB/T5009.15-2003) colorimetric method is adopted, which means that after digestion of the sample, under alkaline conditions, cadmium ions and 6-bromophenyl propionazole azonaphthol form a red complex, which is dissolved in trichloromethane for colorimetric determination.

5. The detection principle and adopted standards of heavy metal mercury

The national standard (GB/T5009.17-2003) dithizone colorimetric method is adopted, which means that after digestion of the sample, under acidic conditions, mercury ions and dithizone form an orange red complex, which is dissolved in trichloromethane for colorimetric determination.

Functional features:

1. This instrument combines various functions in one, without the need for user provided accessories, and can flexibly flow for detection.

2. The Android operating system adopts ARM Cortex-A7 as the main control chip, RK3288/4-core processor, with a main frequency of 1.88GHz, which runs faster and has stronger stability.

3. Six detection channels (solid-state design) can quickly detect six samples at once, greatly improving detection efficiency and reducing detection costs.

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

5. The built-in crop expert fertilization system can calculate the recommended fertilization amount for over a hundred national agricultural economic crops, fruit trees, and other target yields, and scientifically guide agricultural production based on fertilization formulas. The soil testing formula fertilization results can be printed, including crop types, fertilizer types, target yield, total demand, and recommended fertilization plans.

6. The instrument comes standard with WiFi wireless upload, 4G network transmission, and GPRS wireless remote transmission function, allowing for quick data upload.

7. The instrument is equipped with a large capacity memory, which supports viewing all historical detection records and transmitting all detection data.

8. Equipped with a smart cloud agriculture platform, the instrument can selectively or in bulk upload detection data wirelessly after being connected to the wireless network, facilitating long-term data management and visual analysis for users.

9. The instrument has both USB and Ethernet interfaces, and can copy data from a USB drive at any time.

10. You can log in to the cloud platform anytime with your mobile phone and view historical data online

11. Built in plant nutrition diagnostic standard map, based on images of nutrient deficiencies in various crops, leaf comparison is performed to diagnose abundance and deficiency.

12. 4 wavelength professional testing cold light source (red, blue, green, orange), stable light source wavelength, long-term continuous operation without temperature drift phenomenon, with a lifespan of up to 100000 hours, good reproducibility, and high accuracy.

13. The colorimetric cell adopts a standard 1cm cuvette, which has no mechanical displacement or wear. The optical path is tested and positioned to effectively shield external light interference and ensure that the detection results are better than the national standard requirements.

14. The instrument system comes with sample pre-treatment operation videos, and various sample detection methods can be viewed by clicking on the video module. Testing personnel do not need to self-study the manual, making teaching and guidance convenient and fast for beginners to operate quickly.

15. Equipped with a new generation of high-speed thermal printer (without ribbon), the printed content includes information such as testing unit, testing personnel, testing items, channel number, absorbance, nutrient content (mg/kg), testing time, and QR code

16. A highly sensitive 7-inch true color touch screen with more efficient and user-friendly operation, high-definition and interactive display, greatly reducing the tedious operation and errors of traditional instruments.

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

18. Multiple account passwords can be set for login, with an efficient UI interaction interface. Different users can freely add, edit, and detect information. After saving, it can be used for a long time.

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

20. Equipped with a built-in low voltage prompt function, it can clearly indicate the battery level during detection, avoiding test data deviation. At the same time, it has a power-off protection function, which automatically saves data during power-off to prevent data loss.

21. The AC/DC dual-purpose power supply mode is equipped with a large capacity rechargeable lithium battery, which can work continuously for more than 10 hours when fully charged. At the same time, it can be connected to an external vehicle power source for energy storage.

22. The instrument has a Chinese English switching function, which can meet export requirements.

23. High strength PVC engineering plastic suitcase design, sturdy and durable, easy to carry.

Technical parameters:

1. Power supply: AC 220 ± 22V DC 12V+5V (the instrument has a built-in lithium battery and can also be used as a 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: Display digital drift free within one hour (transmittance measurement); Digital drift within two hours shall not exceed 0.3% (0.003 for transmittance measurement) and 0.001 for 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. Seismic grade: IP65

14. Instrument size: 48 x 34.5 x 22cm

15. Net weight of the host: 5.2kg