NY/T 1121.12-2006Soil Testing. Part 12: Method for determination of soil total chrome (English PDF)

Foreword

NY/T 1121 Soil testing is a standard series, which include the following parts.

- Part 1.Soil sampling, processing, and reposition;

- Part 2.Method for determination of soil pH;

- Part 3.Method for determination of soil mechanical composition;

- Part 4.Method for determination of soil bulk density;

- Part 5.Method for determination of soil cation exchange capacity in

calcareous soil;

- Part 6.Method for determination of soil organic matter;

- Part 7.Method for determination of available phosphorous in acid soil;

- Part 8.Method for determination of soil available boron;

- Part 9.Method for determination of soil available molybdenum;

- Part 10.Method for determination of soil total hydrargyrum;

- Part 11.Method for determination of soil total arsenic;

- Part 12.Method for determination of soil total chrome;

- Part 13.Method for determination of soil exchangeable calcium and

magnesium;

- Part 14.Method for determination of soil available sulphur;

- Part 15.Method for determination of soil available silicon;

- Part 16.Method for determination of total water-soluble salt;

- Part 17.Method for determination of soil chloride ion content;

- Part 18.Method for determination of soil sulphate content;

...

This part is part 12 of NY/T 1121.

This part was proposed by AND shall be under the jurisdiction of Ministry of

Agriculture of the People's Republic of China.

Soil testing -

Part 12.Method for determination of soil total chrome

1 Scope of application

This part is applicable to the determination of chrome in various soils.

2 Method summary

After sulphuric acid, nitric acid, and phosphoric acid digestion, chromium

compounds in the soil are converted into soluble substance; USE potassium

permanganate to oxidize chromium into hexavalent chromium; USE sodium

azide to reduce and eliminate the excessive potassium permanganate; under

acidic conditions, hexavalent chromium reacts with diphenylcarbazide (DPC) to

form a purple-red compound, which is measured spectrophotometrically at a

wavelength of 540 nm.

3 Instruments and equipment

4 Reagents and solutions

The reagents and water used in this test method, unless otherwise stated, refer

to analytical grade reagents and grade 1 water as specified in GB/T 6682.The

solution, if not specified, is an aqueous solution.