Simple operation process of hexavalent chromium reagent

Author: 同奥科技

Abstract: 本文介绍了测试水样中六价铬浓度的简易操作流程。根据预判的浓度范围，选择相应的操作步骤：0-1 mg/L使用低量程步骤，1-5 mg/L使用高量程步骤，超过5 mg/L需稀释后测定，结果乘以稀释倍数。水样会显示紫红色，颜色深浅反映六价铬浓度。操作时需避免交叉污染，使用合适的移液工具，并定期校准移液枪以确保准确性。

Concentration prediction:Before testing the water sample, first predict the hexavalent chromium value of the water sample, and select the operation steps corresponding to the range, e.g., predict the hexavalent chromium concentration value0-1mg/L, you need to select the operation step of 0-1mg/L range; If the predicted concentration value is 1-5mg/L, the procedure of the 1-5mg/L range is selected.

1. When the predicted value is in the range of 0-1L mg/L

If hexavalent chromium is present, the water sample will appear purplish-red, and the darker the color, the higher the concentration value. Analytical procedure: Hexavalent chromium L; Watch out for overrange tips!

The simple operation process of hexavalent chromium reagent is shown in Figure 1

2. When the predicted value is in the range of 1-5L mg/L

The simple operation process of hexavalent chromium reagent is shown in Figure 2

3. When the predicted value exceeds 5 mg/L

The water sample needs to be diluted to the corresponding concentration value in sections 1-2 above, and then operated according to the corresponding range, and the determination result is multiplied by the dilution factor.

4. Test steps on the computer

The simple operation process of hexavalent chromium reagent is shown in Figure 3

5. Precautions

◆ If there is hexavalent chromium, the water sample shows purple red, and the darker the color, the higher the concentration value of the water sample. Watch out for overrange tips!

◆ Pay attention to cross-contamination, use different measuring utensils for different liquids (pay attention to changing the tip when using a pipette).

◆ Use appropriate pipetting tools to take liquids, and large range measuring tools cannot measure small volumes of water samples, such as: 5mL pipettes cannot be used to remove 2mL and below liquidsFor liquids less than or equal to 2mL, it is recommended to pipette twice with a 1mL pipette.

◆ When using a pipette, it is necessary to calibrate the pipette frequently (it is recommended to do so once a week), and pay attention to replacing the tip during use.

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