Formic acid for industrial use (4)

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Sodium carbonate is added to laboratory samples to make sulfates form sulfate , and barium chloride solution is added in the presence of hydrochloric acid to form barium sulfate , which is turbidity with the standard turbidity solution

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Visible spectrophotometer with 5cm cuvette

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Weigh 10g of laboratory sample, accurate to 0.

Note: According to the sulfate content in the sample, the sampling volume can be adjusted appropriately, and the volume of the standard solution in Table 3 can be adjusted in the same proportion

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According to the product specifications, take the sulfate (SO ₄ ) standard solutions of different volumes (see Table 3) into three 50 mL colorimetric tubes, and add 1 mL of hydrochloric acid solution as the sulfate standard turbidity solution
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Table 3 The volume of sulfate (SO ₄ ) standard solution in the standard turbidity solution of products of different specifications

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3 Visual method

In the above test solution and the sulfate standard turbidity solution, respectively add the seed solution, and add water to 25mL, shake it up, and leave it for 25 minutes.
The test melt and the sulfate standard turbidity solution are subjected to axial turbidity
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Determine the level of this indicator
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4 Spectrophotometry (Arbitration Law)

In the above test solution and sulfate standard turbidity solution, respectively add seed solution, add water to the well to 25mL, shake well, place for 25min, use water as a blank, and measure the absorbance at a wavelength of 420nm
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Compare the absorbance value of the test solution with the absorbance value of the sulfate standard turbidity solution corresponding to the corresponding specification to determine the level of this index
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Related links: Formic acid for industrial use (3)