Instructions for use

Product number: YC002K04H

1. Method Principle

Formaldehyde reacts with AHMT to form a purple compound. The color of the solution is proportional to the content of formaldehyde in the air.

2. Scope of application

This kit is suitable for the rapid detection of formaldehyde in the air.

3. Instruments and equipment

(1) Large bubble absorption bottle: The inner diameter of the air outlet is 1 mm, and the distance from the air outlet to the bottom of the tube is 5 mm.

(2) Constant current sampler: The flow range is 0.1-1 L/min, the flow rate is adjustable, and the flow error is less than 5% of the set value.

(3) Formaldehyde tachometer/spectrophotometer: 550 nm wavelength can be set, with a 1 cm cuvette, with water as a reference, to measure the absorbance (concentration) of the solution.

IV. Reagent preparation

(1) Absorption solution: Measure 5 mL of the absorption stock solution into a graduated cup, add water to 25 mL, which is the absorption solution, prepared before use. During the preparation process before sampling, the absorption solution reagent bottle needs to be rinsed 2-3 times.

(2) The water used in this method is purified water or deionized water.

V. Sampling operation

(1) Before sampling, calibrate the sampling flowmeter with a first-stage soap film flowmeter, with an error of 5%.
(2) point sampling, with 5 mL absorption liquid into the bubble absorption bottle, with 0.5L/min flow rate sampling, gas volume 10 L.
(3) record the temperature and atmospheric pressure of the sampling point at that time (need to participate in the result calculation), but also need to record (not limited to): humidity, pollution source, sampling date, time, location, distribution method, sampling number and sampling personnel, etc. for detailed records.

(4) After the sampling is completed, the sample liquid is retained for testing.

Five, analysis operation

(1) Take 2 colorimetric tubes as sample tubes and blank control tubes.

(2) Sample tube: Add 2mL of sample solution, reagent A 0.3mL (about 6 drops), reagent B 0.3mL (about 6 drops), shake well and let stand for 10 minutes;

blank control tube: Add 2mL of uncollected air absorption solution, reagent A 0.3mL (about 6 drops), reagent B 0.3mL (about 6 drops), shake well and let stand for 10 minutes.

(3) Continue to add reagent C 0.2mL (about 4 drops) to the sample tube/control tube respectively, shake well and let stand for 5 minutes before reading on the machine.

6. Results Analysis

(1) The formaldehyde tachymeter contains curves, and the result calculation can be read directly.

(2) When the spectrophotometer only shows the absorbance, it needs to be converted to obtain the formaldehyde concentration.
The gas recovery volume is converted into the sampling volume in the standard state or the sampling volume in the reference state.
The result is calculated according to the formula for calculating the formaldehyde concentration in the indoor air in the figure.

A--- the absorbance of the sample solution; A0---The absorbance of the reagent blank solution;

B---Calculation factor, derived from the inverse of the slope of the standard curve; V0---The sampling volume under the standard condition, L;

Seven, kit composition

Serial number

Specification

Composition 11727798400times/box

1

reagent A

1 bottles

2

reagent B

1 bottles

3

reagent C

1

4

bottle Absorption stock solution

1 bottles

5

graduated cup

1

6

colorimeter

1 package

Eight, storage conditions