HJ 636-2012Water quality - Determination of total nitrogen - Alkaline potassium persulfate digestion UV spectrophotometric method (English PDF)

Foreword

This Standard is specified so as to implement Environmental Protection Law of

the People 's Republic of China, Water Pollution Control Act of the People 's

Republic of China, to protect environment, to protect human health, to

standardize the determination method for total nitrogen in water.

This Standard specifies determination of total nitrogen in surface water,

groundwater, industrial wastewater and domestic sewage - Alkaline potassium

persulfate digestion UV spectrophotometric method.

This Standard is the modification of Water quality - Determination of total

nitrogen - Alkaline potassium persulfate digestion - UV spectro photometric

method (GB 11894-89).

This Standard was issued in 1989 for the first time. The original drafting

organization was Shanghai Environmental Monitoring Center. This is the first

revision. The main content of revision is as follows.

- expanded the scope of standard application;

- added nitrogen content requirements of sodium hydroxide and potassium

persulfate and method for determination of nitrogen content;

- added quality assurance and quality control provisions;

- added terms and conditions on precautions.

Since the date of implementation of this Standard, the national environmental

protection standard. Water quality - Determination of total nitrogen - Alkaline

potassium persulfate digestion - UV spectro photometric method (GB 11894-

89) approved and issued by former China State Environmental Protection

Administration on December 25, 1989 shall be abolished.

Annex A of this Standard is informative.

This Standard is organized and made by Department of Science and

Technology Standards, Ministry of Environmental Protection.

Main drafting organization of this Standard. Dalian Environmental Monitoring

Center.

The verification organizations of this Standard. Tianjin Environmental

Monitoring Center, Liaoning Provincial Environmental Monitoring Experimental

Center, Shenyang Environmental Monitoring Center Station, Anshan

Environmental Monitoring Center Station, Jinzhou Environmental Monitoring

Center Station, Yingkou Environmental Monitoring Center Station.

Water quality - Determination of total nitrogen -

Alkaline potassium persulfate digestion UV

spectrophotometric method

1 Application scope

This Standard specifies water quality - determination of total nitrogen - alkaline

potassium persulfate digestion UV spectrophotometric method.

This Standard is applicable to the determination of total nitrogen in surface

water, groundwater, industrial wastewater and domestic sewage.

When the amount of sample is 10 ml, the detection limit of this method shall be

2 Normative references

The following standards contain the provisions which, through reference in this

Standard, constitute the provisions of this Standard. For undated reference

documents, the latest versions apply to this Standard.

HJ/T 91 Technical specifications requirements for monitoring of surface

water and waste water

HJ/T 164 Technical specifications for environmental monitoring

3 Terms and definitions

For the purposes of this document, the following terms and definitions apply.

total nitrogen (TN)

under the conditions specified by this Standard, total nitrogen in dissolved

nitrogen and suspended solids of samples which can be determined, including

nitrogen in nitrite nitrogen, nitrate nitrogen, inorganic ammonium salt, dissolved

ammonia and most of the organic nitrogen compounds

Dry it at 105 ~ 110°C for 2h. Cool it to room temperature in dryer.

7 Apparatus