SORBENT TRAP ANALYSIS PROCEDURE - Ohio Lumex Co.

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2. ANALYTICAL METHOD DETAILSThe sorbent trap tube end cap is removed; the glass wool plug closest to the appropriatecarbon bed is carefully removed and separated from the carbon fraction. The sorbent istransferred into a quartz ladle and then covered with anhydrous sodium carbonate. The ladleis inserted into the heated analyzer thermo catalytic conversion chamber. As a result,mercury is converted from a bound state to the atomic state by thermal decomposition in thefurnace and is then detected by atomic absorption with Zeeman correction. The mercuryconcentration is measured and recorded using an automated data acquisition system. Boththe glass wool plug and the sorbent of each bed are analyzed for the trap and the finalmercury mass is the sum of the measurements.The procedure for the trap analysis is described here step by step,a. Instrument start-upb. Preliminary determination of mercury mass in the traps,c. Analyzer calibration,d. Trap analysis,e. Verification of calibration during testing and postcalibration,f. Data saving and results reporting.2.1 Instrument Start-up2.1.1 Set up the connections among RA-915+ analyzer, RP-M324 attachment, mercuryfilter and laptop computer.2.1.2 Connect power cord to RA-915+, RP-M324 and laptop computer.2.1.3 Complete setup with heat shield.2.1.4 Turn on computer.2.1.5 Turn on RA-915+ power toggle switch and ignite mercury lamp by pressing andholding lamp ignition button for 3 seconds.2.1.6 Turn on the RP-M234 power supply. Adjust the carrier pump flow to be adesired one. Flow rate 2 liters/min is for profile 1, 4.5 liters/min for profile 2 and3. Please note the EZ zone controller does automatic flow selection based onprofile number. For SD series controllers Flow setting is manual and usuallysame for Prof 1 and 2 and equal to 4 LPM.2.1.7 Start the RA-915 software from the Windows main screen by double click theicon . The RA-915+ Main menu screen will appear.2.1.8 Select “Complex” on RA-915+’s main menu screen, a table window (“Table.Complex analysis”) and a graph window (“Complex Sample analysis Graph”)4
ecome activ. Click on the window headers to alternate between the twoscreens.2.1.9 Click the “run” icon from graph window to see the running signals.2.1.10 Enter information in table window, Name and Save folder in My Documents.2.1.11 Allow the system to be heated at 680/650C for at least 60 minutes beforecalibration.2.1.12 Click the icon to view the average baseline value and the baseline RSD.After 20 mins system running, if the RSD is larger than 5, shut off the furnaceand clean the detector windows (see Reference 1 for maintenance).2.1.13 Click the icon (baseline check) and allow the baseline to adjust for 10seconds. After 10 seconds click on again, to turn off the baselineadjustment and complete the baseline correction. Repeat this step until theaverage baseline is near zero and the RSD is less than 4. After the initial start-upof the instrument, baseline drift will be maximum and minimized with heating.2.2 Preliminary Determination of Mercury MassThe expected mercury mass is an estimate of the total mercury collected in section 1 of asorbent trap. The determination for this amount is very important to decide the calibrationrange and what profile should be used to perform the analysis.Knowledge of estimated stack mercury concentrations and total sample volume may berequired prior to analysis. Information may be received from the stack testers. However, ananalyst should always evaluate the traps based on the information shown in the “Chain ofCustody”. Sampling duration, flow rate, dust temperature, meter temperature and dry gasvolume are necessary for the evaluation. A proper testing profile can be chosen after trapevaluation.Table 1 and Table 2 show the most current, up to date profiles used in the Ohio Lumex RA-915+ with M324 attachment, EZ-Zone controller or SD controller.Table 1. Profiles and Applications (EZ-Zone Controller)Profiles Flow Rate Test Range Test Time Trap Performance(L/min) (ng)(second)1 2 1-2,000 100 Not Ramping 0.5-2 hours sampling(RATA)2 4.5 10-10,000 150 Not Ramping Up to 5 days sampling (wet5
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SORBENT TRAP ANALYSIS PROCEDURE - Ohio Lumex Co.

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