HJ 734-2014 English PDF (HJ734-2014)

Delivery: 3 seconds. Download true-PDF + Invoice.
Get QUOTATION in 1-minute: Click HJ 734-2014
Historical versions: HJ 734-2014
Preview True-PDF (Reload/Scroll if blank)

HJ 734-2014: Stationary source emission. Determination of volatile organic compounds. Sorbent adsorption and thermal desorption gas chromatography mass spectrometry method
HJ 734-2014
HJ
NATIONAL ENVIRONMENTAL PROTECTION STANDARD
OF THE PEOPLE'S REPUBLIC OF CHINA
Stationary source emission - Determination of volatile
organic compounds - Sorbent adsorption and thermal
desorption gas chromatography mass spectrometry
method
ISSUED ON: DECEMBER 31, 2014
IMPLEMENTED ON: FEBRUARY 01, 2015
Issued by: Ministry of Environmental Protection
Table of Contents
Foreword ... 4 
1 Scope of application ... 5 
2 Normative references ... 5 
3 Terms and definitions ... 6 
4 Principle of method ... 6 
5 Reagents and materials ... 6 
6 Instruments and equipment... 8 
7 Sample ... 9 
8 Analysis steps ... 11 
9 Result calculation and expression ... 14 
10 Precision and accuracy ... 16 
11 Quality assurance and quality control... 16 
Annex A (normative) Detection limit of target substance and lower limit of
determination ... 18 
Annex B (informative) Precision and accuracy ... 20 
Annex C (informative) Use and selection of adsorption tube ... 25 
Annex D (informative) Standard total ion diagram ... 28 
Annex E (informative) Other target volatile organic compounds ... 29 
Stationary source emission - Determination of volatile
organic compounds - Sorbent adsorption and thermal
desorption gas chromatography mass spectrometry
method
WARNING: Volatile organic compounds are flammable substances. Some
of them are toxic. Pay attention to safety when preparing standard
samples and storing. When sampling in potentially explosive
environments, pay special attention to the safety of sampling equipment
and operations.
1 Scope of application
This Standard specifies sorbent adsorption and thermal desorption gas
chromatography mass spectrometry method of determination of 24 volatile
organic compounds in stationary source emission.
This Standard is applicable to the determination of 24 volatile organic
compounds in stationary source emission. 24 volatile organic compounds
include: acetone, isopropanol, hexane, ethyl acetate, benzene,
hexamethyldisiloxane, 3-pentanone, heptane, toluene, cyclopentanone, ethyl
lactate, butyl acetate, PGEA, ethyl benzene, p-xylene / m-xylene, 2-heptanone,
styrene, o-xylene, anisole, benzaldehyde, 1-decene, 2-nonanone, 1-dodecene.
This method can also be used after other volatile organic compounds have
been verified.
When the sampling volume is 300 ml, the detection limit of the method in this
Standard is 0.001~0.01mg/m3; the lower limit of determination is
0.004~0.04mg/m3. See Annex A for the details.
2 Normative references
The provisions in following documents become the provisions of this Standard
through reference in this Standard. For undated references, the latest edition of
the referenced document applies.
HJ 639, Water quality - Determination of volatile organic compounds - Purge
and trap/gas chromatography-mass spectrometer
5.2 Internal standard solution: ρ=2000μg/ml or 2500μg/ml, commercially
available certified internal standard solution (for analysis of volatile organic
compounds).
5.3 BFB: ρ=50μg/ml.
For GC-MS performance inspection. Take an appropriate amount of
chromatographically-pure BFB and prepare it in a certain volume of methanol
(5.1).
5.4 Standard substance
The standard substance of volatile organic compounds can use gas standard
or liquid standard.
5.4.1 Gas standard
Standards for gas stored in high-pressure tanks must comply with national
standards or standards certified by international authorities and be used within
the validity period. It is recommended to use dynamic dilution method for
standard gas dilution.
5.4.2 Liquid standard stock solution: ρ=1000μg/ml.
Purchase chromatographically-pure target compounds. Take a certain volume
and use methanol (5.1) to dilute and prepare 1000μg/ml standard stock solution.
Commercially available certified mixed standard solutions can also be
purchased. The concentration is 2000μg/ml.
5.5 Substitute standard solution: ρ=2000μg/ml or 2500μg/ml, commercially
available certified substitute standard solution (for analysis of volatile organic
compounds). The chromatographically-pure deuterium in the target compound
can also be prepared with methanol (5.1).
5.6 Adsorbents: Tenax GR (specific surface area is 35m2/g), Carbopack B
(specific surface area is 100m2/g), Carbopack C (specific surface area is
10m2/g), Carboxen 1000 (specific surface area is 1200m2/g), or other
equivalent adsorbents such as domestic GDX-502 (specific surface area is
170m2/g), GDX-201 (specific surface area is 510m2/g), GDX-101 (specific
surface area is 330m2/g). The particle size of commonly used adsorbents is
generally 60~80 mesh.
5.7 Adsorption tube: stainless steel material; inner diameter is 5mm.
Combination 1 adsorption tube: built-in Tenax GR, Carbopack B; lengths are 30
mm and 25mm respectively.
6.7 Flow calibrator: be able to accurately measure the flow rate at 5~500ml/min;
flow accuracy is 2%; electronic mass flow meter shall be used.
6.8 Semiconductor refrigeration dehumidification device or ice bath small
impact moisture collector: for semiconductor refrigerator (current is 3A, voltage
is 12V, maximum temperature difference is 60°C), the material of the gas path
in the dehumidifier is made of stainless steel and PTFE tube; dehumidification
components are designed as replaceable components; when the sample gas
flow is < 3L/min, the inlet sample gas temperature is < 60°C (when it is the two-
way series connection, it is < 120°C), the outlet sample gas temperature is
1.5~4.0°C.
6.9 Micro syringe: 1.0, 5.0, 10.0, 25.0, 50.0, 100, 250 and 500μl.
6.10 Commonly used instruments and equipment in general laboratories.
7 Sample
7.1 Pre-investigation and pre-monitoring
Before testing the exhaust of volatile organic compounds in stationary source,
it shall pre-investigate the pollution source information, including company
name, raw materials, intermediates, products, by-products, production process,
position of sampling hole of exhaust cylinder, total organic carbon (or non-
methane total hydrocarbon) emission concentration, as well as common
organic pollutants listed in industry emission standards.
Use the combination 3 adsorption tube for sampling of pre-monitoring sample
collection. It can use thermal desorption gas chromatography mass
spectrometry method analysis. It can also use sampling tank sampling gas
chromatography-mass spectrometry analysis. Use pre-monitoring to determine
the components of volatile organic compounds in the exhaust gas of each
stationary source.
7.2 Preparation of adsorption sampling tube
Immediately use sealing cap to seal both ends of the aged adsorption sampling
tube. Store in an airtight sealed bag or box. The sealed bag or sealed box is
stored in a box containing activated carbon or in a desiccator. Store at 4°C. If
necessary, before sampling, in the aged adsorption tube, add a certain amount
of substitute standard (usually the middle concentration of the calibration curve).
For loading method, see 8.2.2.
7.3 Sample collection
7.3.1 Adsorption tube sampling
Figure 1 -- Exhaust gas sampling system
7.3.2 Air bag-adsorption tube sampling
Refer to HJ 732 for air bag sampling of volatile organic compounds in exhaust
gas from stationary source. Air bag adopts 3-liter Tedlar bag. Gather about 2
liters of gas. Connect the air bag to the adsorption sampling tube within 8 hours.
Use the sample collection device (6.6) ...