T/SXSYSJSXH 0002-2024 Active

Scope: This standard specifies the atomic fluorescence spectrometry method for determining the effective mercury in soil using diethylenetriamine pentaacetic acid (DTPA) extraction. This standard is applicable to the determination of the effective mercury in soil; Main technical content: 4. Method principle: The effective mercury in soil is extracted using a DTPA-CaCl2-TEA buffer solution and determined by atomic fluorescence spectrometry. After pretreatment, the solution is introduced into the atomic fluorescence instrument. Under the reduction of potassium borohydride in an acidic environment, mercury atoms are generated, which are introduced into the quartz atomizer by carrier gas. Under the excitation of a special mercury hollow cathode lamp, atomic fluorescence is produced. Within a certain concentration range, the fluorescence intensity is proportional to the arsenic content in the solution. 5. Interference and elimination 5.1 Transition metals such as copper at a certain concentration may interfere with the determination. Under the experimental conditions of this standard, samples containing less than 100mg/L Cu2+, 50mg/L Fe3+, 1mg/L Co2+, 10mg/L Pb2+, and 150mg/L Mn2+ do not affect the determination. 5.2 Common anions do not interfere with the determination. 5.3 Elimination of physical interference: A double-layer quartz tube atomizer is selected, with both inner and outer layers filled with argon. The outer layer forms a protective layer to isolate the air, preventing the ground state atoms of the elements to be determined from colliding with oxygen and nitrogen in the air, thereby reducing the influence of fluorescence quenching on the determination. 6. Reagents and materials Unless otherwise specified, analytical pure reagents conforming to national standards are used for analysis, and the experimental water is newly prepared deionized water or water of equivalent purity. 6.1 Triethanolamine (C6H15NO3): TEA, analytical pure. 6.2 Diet