Tekran 2537 Manual Injections

 

Purpose:  Follow the steps below to perform Tekran 2537 Manual Injections, also referred to as Primary Standard Additions.

 

Required Equipment:    2505 Mercury Vapor Calibration Unit

                                              Calibrated Hamilton Digital Syringe

                                              2537 Injection Port

                                              2537 6mm Injection Port Silicone Septum

                                              2505 10mm Teflon® backed Silicone Septum

                                              2505 Septum Removal Tool

                                                                                               

Reference:        

 

1.       Ensure the Tekran Model 2505 Mercury Vapor Calibration Unit is turned on and allowed to equilibrate for at least 24 hours prior to its anticipated use.

2.       Insert the Hamilton digital syringe into the Model 2505 unit once the flask temperature is stable and cycle the plunger up and down two times leaving the plunger up with the syringe fully loaded with mercury saturated vapor to equilibrate overnight but at minimum for two to three hours.  Conditioning the syringe overnight is preferred and will help ensure best syringe operation.

CAUTION

If the Model 2505 is moved, bumped, or otherwise disturbed it will be necessary to change the septum and clean the support collar with a cotton swab to prevent small mercury beads from contacting the syringe needle.

CAUTION

Never insert the Hamilton digital syringe into the Model 2505 unit unless the flask temperature is at 15 degrees C. If the flask temperature is warmer than the syringe body, then mercury vapor will condense in and ruin the syringe.

 

3.       Down the Tekran channel, stop the instrument, and initiate a perm tube calibration.

4.       After the perm tube calibration has finished, start the Tekran in run mode, and flip the zero air switch on and the pump flow switch to desorb.  It is also a good idea at this time to turn all heater switches off in case the injections run past the adsorption cycle into the desorption cycle.  If the denuder and RPF heaters are left on, injection results will be unreliable.  Injections performed during the desorption cycle are the same as during the adsorption cycle except that for injections during the desorption cycle, the current scaling factor in the 2537 must be recorded in the Tekran spreadsheet.  

5.       When the run concentrations on zero air are close to or equal to zero, conduct one standard addition injection on Trap A and one injection on Trap B as follows:

a.       On the 2537 front panel keypad, press the4button until the Timing display is shown to see the current operation being performed on Trap A and Trap B as well as the total duration and time remaining for that step. 

b.      When the Timing display shows the status of the desired trap to be injected is CONT-M and there is at least 180 seconds of time remaining, turn on the digital syringe and ensure the display reads 0.00 when the plunger is fully depressed.

c.       Cycle plunger slowly up and down two times.

d.      Slowly pull the syringe up to approximately 17 µl and make note of the HgSrc temperature displayed on the Model 2505 unit.

e.      Quickly remove the syringe and position yourself in front of the 2537 analyzer.

f.        Using the thumb screw, smoothly decrease the syringe volume to 15 µl.

g.       Fully insert the syringe needle into the 2537 injection port.

h.      Pull the syringe needle back out slightly and then fully depress the plunger to inject all mercury saturated vapor.

i.         Remove the syringe needle from the injection port.

6.       Insert the Hamilton syringe back into the Model 2505 unit and pull the plunger up and leave the syringe fully loaded with mercury saturated vapor.

7.       Record preliminary injection information into the Tekran spreadsheet and then read the Hg concentration ng m-3 displayed in the data logging program for the trap that was injected and record results in the spreadsheet to calculate the difference between actual and calculated mercury. 

a.        If the concentration on the previous trap was not at zero before the injection, then the decision to subtract this value from the peak area for the trap that was injected should be made by the individual performing the injections.  If concentration was not at zero with zero air on, and the reading is thought to be caused by low level, constant, residual contamination within the sampling line, filters, or instrument, then it would be appropriate to subtract out this value.

b.      In all such situations described above, individual injection results in the spreadsheet should be annotated to indicate any corrections that were made.

8.       If the difference of the second injection is ≤ 5% then no further action is required.

9.       If the difference of the second injection is ≥ 5% then perform two more injections.

10.   If the difference of the fourth injection is still ≥ 5% then a full perm rate calibration is required.  Contact Plano for assistance.

11.   When finished with the injections, stop the instrument, replace the 2537 injection port septum and restart the instrument in run mode.  Ensure you turn the zero air switch, pump switch, and all heater switches back to auto.  Note: replacing the 2537 injection port septum while the Tekran is in run mode will cause shelter air to be drawn in through the injection port.

12.   Remove the syringe from the 2505 unit and store the syringe in its protective case.

13.   Turn the 2505 unit off, remove the old septum using the septum removal tool, and install a new septum with the Teflon® side facing down.

14.   Record injection results in the Tekran spreadsheet, attach the document to the SM ticket, and upload it to Sharepoint.