Simple operation process of volatile phenol reagent

Concentration prediction:Before testing the water sample, first predict the volatile phenol value of the water sample, and select the operation steps corresponding to the range, for example: predicting the volatile phenol concentration value0-5mg/L, you need to select the operation step of 0-5mg/L range; If the volatile phenol concentration is predicted to be 5-10mg/L, the 5-10mg/L range is selectedSudden.

Notes:Before the volatile phenol measurement, the water sample must be pre-distilled! For details of sample pretreatment, please refer to HJ503-2009 "Water Quality - Determination of Volatile Phenols 4-Aminoantipyrine spectrophotometry.

Refer to the diagram below to connect the distillation unit

The simple operation process of volatile phenol reagent is shown in Figure 1

1. Take 250 ml of sample and pipette into a 500 ml all-glass still and add 25 ml of phenol-free water (i.e., steamDistilled water), add a few glass beads to prevent overboiling, and add a few drops of 0.5g/L methyl orange indicator solution, if testedIf the sample is not orange-red, it is necessary to continue to add (1+9) phosphoric acid solution, connect the condenser, and heat and steamDistill, collect 250 ml of distillate into a volumetric flask.

2. During the distillation process, if you find that the methyl orange-red color fades, it should be cooled after the distillation is completed, and then 1 is addedDrop 0.5g/L methyl orange indicator solution. If it is found that the residual liquid is not acidic after distillation, it should be resampled.Increase the amount of (1+9) phosphoric acid solution and distill.

Note 1: The distillation equipment used should not be mixed with the distillation equipment for the determination of industrial or domestic wastewater. every timeBefore and after the test, the entire distillation equipment should be cleaned.

Note 2: Do not use rubber stoppers or rubber tubes to connect the distillation flask to the condenser to prevent the assayInterference.

1. When the predicted value is in the range of 0 -5mg/L

If there is volatile phenol, the water sample will show orange-red, and the darker the color, the higher the concentration value of the water sample. Analytical procedure: Volatile phenol L; Watch out for overrange tips!

The simple operation process of volatile phenol reagent is shown in Figure 2

2. When the predicted value is in the range of 5 - 10mg/L

The simple operation process of volatile phenol reagent is shown in Figure 3

3. When the predicted value exceeds 10mg /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 volatile phenol reagent is shown in Figure 4

Author: 同奥科技