Case Study

Mercury Determination for Coal

Sample Preparation
Boats should be pre-baked at 550°C for an hour or analyzed (without a sample) before loading a sample
Samples may be analyzed as air dried
Crush and grind to make the sample size ≤0.2mm

Instrument


Instrument Settings

Oxygen :Flow 300ml/min; purity ≥99.9%    Pressure :0.1 Mpa
Main Furnace
Drying Temp.:300℃                       Time:60s
Combustion Temp.:800℃            Time:180s
Catalyst Furnace Temp.:600℃
Purge Time: 60s
Nominal Sample Mass: 60mg~80mg
Analysis Time: 6minutes/per test

Calibration standard
SARM 20 (coal); GBW11159 (coal) or equivalent Certified Reference Materials.

Method Approval
GB 16659-2008 / ASTM D6722-11

Procedure
1. Prepare instrument as outlined in the operator’s instruction manual ; (check the Inlet pressure、Outlet2 pressure、Furnace temperature、Catalytic tube temperature and Voltage.)
2. Keep the instrument in “prepare” state for at least half an hour;
3. Do three blank samples test to reduce the blank level; (if the blank LC_peak is higher than 0.001, more blank sample is suggested)
4. Weigh one standard sample (70mg) in nickel boat, input the sample weight information in the software, press the “start” button to do test; (Make sure the sample position is correspond to crucible No. in the software)
5. If the standard sample is in the tolerated content range, go to step 6, or you should do two more stand sample test. If the two standard sample is still not in the tolerated content range, you need to built a new calibration curve.
6. weigh two coal sample (70mg) in nickel boat, input the sample weight information in the software, press the “start” button to do test; (Make sure the sample position is correspond to crucible No. in the software)
7. One standard sample to check the calibration after 10 duplicate sample analysis;
8. Repetition of point 6 to point 8 until all samples are processed;

Note
Do Calibrating refer to operator’s instruction manual for details.

Typical Results

CodeNameMass(g)Hg(μg/g)RangeAverage(μg/g)
1Coal0.06120.24510.180-0.2700.2494
2Coal0.06050.2516
3Coal0.06020.2537
4Coal0.05980.2473