GB/T 15516-1995 English PDF (GBT15516-1995)

Delivery: 3 seconds. Download true-PDF + Invoice.
Get QUOTATION in 1-minute: Click GB/T 15516-1995
Historical versions: GB/T 15516-1995
Preview True-PDF (Reload/Scroll if blank)

GB/T 15516-1995: Air quality - Determination of formaldehyde - Acetylacetone spectrophotometric method
GB/T 15516-1995
UDC 628.512.543.062
Z 15
GB
National Standard
of the People’s Republic of China
Air quality - Determination of formaldehyde -
Acetylacetone spectrophotometric method
ISSUED ON. MARCH15, 1995
IMPLEMENTED ON. AUGUST 01, 1995
Issued by. National Environmental Protection Authority;
State Bureau of Technical Supervision.
Table of Contents
1 Subject content and application scope ... 3
2 Principle ... 3
3 Reagents ... 4
4 Instruments ... 6
5 Samples ... 7
6 Steps ... 8
7 Results and expression ... 9
8 Precautions ... 10
Additional Note... 11
Air quality - Determination of formaldehyde –
Acetylacetone spectrophotometric method
1 Subject content and application scope
1.1 Subject content
This Standard specifies the acetylacetone spectrophotometric method to measure
formaldehyde in industrial emissions and ambient air.
1.2 Application scope
1.2.1 This Standard applies to emissions in those industries such as resin
manufacturing, coatings, rayon, plastics, rubber, dye, pharmaceutical, plaint, and
tanning. And it also applies to determination of formaldehyde vapor produced when
conducting pharmaceutical disinfection, corrosion, and fumigation.
1.2.2 When the sampling volume is 0.5~10.0 L, the measuring range is 0.5~800
mg/m3.
1.2.3 When formaldehyde concentration is 20 µg/10 ml, coexist 8g of phenol (400
times), 10mg of acetaldehyde (500 times), 600mg of ammonium ion (30000 times)
without interference; coexist SO2, less than 20 µg, NO2 is less than 50 µg, the
recovery of formaldehyde shall not be less than 95％.
2 Principle
After formaldehyde gas is absorbed by water, then in the acetic acid-ammonium
acetate buffer solution of PH=6, it has chemical action with acetylacetone. Under the
condition of boiling water bath, it quickly generates stable yellow compound. Measure
it at wavelength of 413 nm. The response equation is as follows.
than 99％.
4.4 Colorimetric tube with stopper. With 10ml and 25ml scale, calibrated.
4.5 Spectrophotometer. Attached with 1cm absorption cell.
4.6 Standard Pitot tube. With correction factor.
4.7 Inclined micro-manometer.
4.8 Sampling lead pipe. Teflon tube. Inner diameter is 6~7mm, with glass fiber filter in
front of the lead pipe.
4.9 Aneroid barometer.
4.10 Mercury thermometers. 0~100°C.
4.11 pH acidity.
4.12 Water bath.
5 Samples
5.1 Sample collection
Sampling system is in-series consisted of sampling lead pipe (4.8), sampling
absorption tube (4.3), and air sampler (4.1). The volume of absorption tube is 50ml or
125ml. The volume of absorbing liquid (3.2) is 20ml or 50ml respectively. At flow rate
of 0.5~1.0L/min, sample the air for 5~20min.
5.2 Sample storage
Collected sample shall be stored up at 2~5°C. Complete the analysis in 2 days, so as
to prevent formaldehyde from oxidation.
5.3 Calibration of sample volume
5.3.1 Flow calibration
When sampling, the air sampler (4.1) shall be calibrated with soap film flowmeter
(4.2).
Calculate the sampling volume Vm(L) according to formula (3).
nQV r ×′=m ...(3)
In the formula. ′rQ - Flow after calibrating, L/min;
bA - Absorbance of blank test (6.3).
Calculate the formaldehyde content x in the test sample with formula (7).
1 )(x
VBayxor
ay
a ×−=×
= ...(7)
In the formula. 1V - Volume of constant volume, ml;
2V - Test sampling volume, ml.
Calculate the formaldehyde concentration c (mg/m3) in exhaust gas or ambient air
with formula (8).
ndV
=c ...(8)
In the formula. ndV - Standard state volume of sampled gas, (0°C, 101.325kPa) L.
7.2 Precision and accuracy
Analyzed by 6 laboratories, the 2 samples containing 2.96mg/L and 3.55mg/L of
formaldehyde are consistent. The repeatability standard deviations are 0.035mg/L
and 0.028mg/L. The repeatability relative standard deviations are 1.2％ and 0.79％.
The reproducibility standard deviations are 0.068mg/L and 0.13mg/L. The
reproducibility relative standard deviations are 2.3％ and 3.6％. Spiked recovery is
100.3％~100.8％. The spiked recoveries in 4 sample analysis are 95.3％~104.2％.
8 Precautions
Formaldehyde will be oxidized under the sunshine. Therefore, when sampling, it shall
use brown absorption tube. In the transport and storage process of sample, it shall
adopt the measures to avoid light.
Additional Note.
This Standard was proposed by Standard Planning Office of National Environmental
Protection Authority.
This Standard was drafted by Shanghai Environmental Monitoring Center.
The main drafters of this Standard. Ding Li, and Guo Qiuyun.
This standard shall be interpreted by National Environmental Monitoring Station.