SN/T 3365-2012Determination of lead, iron, titanium, copper, manganese, zinc, chromium, aluminium content in quartz sand. Inductively couple plasma atomic emission spectrometric method (English PDF)

4.4 Mercury standard stock solution (1000 µg/mL): use national certified standard

solution or prepare according to GB/T 602.

4.5 Mercury standard intermediate solution (100 µg/mL): accurately pipette 10 mL of

mercury standard stock solution (4.4) into a 100 mL volumetric flask. Add 5 mL of nitric acid (4.1). Add water to dilute to volume. Shake well.

4.6 Mercury standard working solution series 1: absorb mercury standard intermediate

solution (4.5) to prepare: 0 µg/mL, 0.020 µg/mL, 0.050 µg/mL, 0.100 µg/mL, 0.250

µg/mL, 0.500 µg/mL mercury standard working solution. The solvent is nitric acid (4.2).

Prepare when needed.

4.7 Mercury standard working solution series 2: absorb mercury standard intermediate

solution (4.5) to prepare: 0 µg/mL, 0.50 µg/mL, 1.00 µg/mL, 2.00 µg/mL, 5.00 µg/mL,

10.00 µg/mL mercury standard working solution. The solvent is nitric acid (4.2).

Prepare when needed.

5.1 Mercury analyzer: equipped with a powder direct sampling device, a thermal

decomposition device, an amalgamation device and an atomic absorption device (see

Annex A).

5.2 Analytical balance: division is 0.1 mg.

5.3 Volumetric flask: grade A, 100 mL.

5.4 Pipette tubes: grade A, 1.0 mL, 5.0 mL, 10.0 mL.

5.5 Pipette: 0 µL~100 µL.

5.6 Sample boat: made of quartz or nickel, suitable for instrument use. The volume is not less than 150 µL.

5.7 Agate mortar.

5.8 Standard sieve: 116 µm.

5.9 High purity oxygen: purity >=99.999%.

7.1 Blank test

Do a blank test along with the specimen.

7.2 Sample determination

Accurately weigh 0.09 g±0.01 g of the general analysis test coal sample. Weighing is accurate to 0.0001 g. Place in the sample boat. Refer to the working conditions in Annex

B for measurement.

7.3 Drawing of working curve

7.3.1 Working curve 1

Adjust the instrument conditions to appropriate working parameters according to the instrument instructions (see Annex B). In order from low concentration to high concentration, pipette 100 µL of mercury standard working solution series 1 (4.6) and add it to the sample boat for measurement. Draw the working curve 1 with the mercury content in the standard working solution as the abscissa and the absorbance as the ordinate.

7.3.2 Working curve 2

Determine the mercury standard working solution series 2 (4.7) according to steps 7.3.1.

Draw working curve 2.

7.4 Verification of standard curve

Measure the standard materials with similar contents at the upper and lower ends of each standard curve, respectively. If the measurement result is within the uncertainty range of the standard value, the standard curve is valid; otherwise, the cause should be found and the standard curve should be redrawn.