Identification of hazardous wastes, identification of leaching toxicity, inductively coupled plasma mass spectrometry (1)

(1) Scope of application

This method is suitable for solid waste and solid waste leachate in silver (Ag), aluminum (Al), arsenic (As), barium (Ba), beryllium (Be), cadmium (Cd), cobalt (Co), chromium (Cr), Copper (Cu), mercury (Hg), manganese (Mn), molybdenum (Mo), nickel (Ni), lead (Pb), antimony (Sb), selenium (Se), thorium (Th), thallium (Tl), The detection of uranium (U), vanadium (V), and zinc (Zn) can also be used for the analysis of other elements, but the accuracy and precision of the method should be given

Table 5-33 Method detection limits specified in GB5085.

(2) Method principle

The sample solution is introduced into the radio frequency plasma by pneumatic atomization.

It is necessary to fully understand the interference involved in this technology and correct it

(3) Reagents and materials

1.

Sulfuric acid , nitric acid , hydrochloric acid , hydrofluoric acid , perchloric acid : superior grade pure reagents that meet national standards

2.

The standard solution is commercially available or self-prepared, the mass concentration of the mixed standard stock solution is 1000 mg/L, and the mass concentration of the mixed standard use solution is 10 mg/L

When preparing multi-element stock standard solutions, attention must be paid to the compatibility and stability of the elements

In addition to Se and Hg, multi-element standard stock solutions A and B (1mL containing 10ug of standards) can be directly divided into 1mL of the single-element standard stock solution in Table 5-34, using reagent water containing 1% (volume fraction) of nitric acid Prepared by diluting to 100mL

Table 5-34 Grouping of element stock standard solutions

3.

Internal standard stock solution: 1mL contains 100ug of internal standard substance

Internal standard solution: 1mL containing 10ug of internal standard substance, take 10mL Sc, Y, In, Tb and Bi standard stock solution, dilute reagent water to 100mL, and store in FEP bottle

(4) Instruments and equipment

(1) Inductively coupled plasma mass spectrometer

(2) Argon gas source, high purity grade (99.

(3) Analytical balance, accurate to 0.
1mg; temperature-controlled electric heating plate, the temperature can be maintained at 95℃; centrifuge; gravity convection drying oven with temperature control system and other supporting equipment
.

(4) Commonly used instruments and equipment for experiments.
All conical flasks, volumetric flasks, pipettes and other glassware used in the experiment are soaked in (1+1) nitric acid overnight, rinsed with deionized water, and dried.

.

(5) Sample pretreatment

1.
Solid waste leachate

The solid waste leachate is in accordance with "Solid waste leaching toxicity leaching method: sulfuric acid and nitric acid method" (HJ/T299), "solid waste leaching toxicity leaching method acetic acid buffer solution method" (HJ/T300), "solid waste leaching toxicity leaching method horizontal oscillation method" (HJ557) to prepare
.

Extraction agent preparation: (take HJ/T299-2007 as an example) add a mixture of concentrated sulfuric acid and concentrated nitric acid with a mass ratio of 2:1 to pure water (about 2 drops of 1L water) to make pH=3.
20
.
After the sample is crushed and sieved, according to the water content of the sample, calculate and add the volume of the required extract at a liquid-to-solid ratio of 10:1 (L/kg), adjust the speed to 30r/min, and oscillate at 23°C for 18h
.
After the above steps are completed, filter
.
Digest according to the electric hot plate digestion method or microwave digestion method, and transfer it to a 25mL volumetric flask after cooling, dilute to the mark with pure water, and shake it well for testing
.

2.
Solid waste

Weigh 0.
5g of the sample (accurate to 0.
1mg) after passing the 100-day sieve in a polytetrafluoroethylene crucible or digestion tank
.
After moistening with a small amount of water, add appropriate amount of hydrochloric acid, nitric acid, hydrofluoric acid, perchloric acid according to the method requirements and order, and digest according to the electric hot plate digestion method or microwave digestion method.
After cooling, transfer to a 50mL volumetric flask, and use experimental water to make the volume constant.
To the marking line, shake well to be tested
.