Below are notes written by Louise Bolge (July, 2009)

 

Axiom Lab rules

 

1.      No food or drink.

2.      No sandals, open toed shoes, or bare feet.

3.      Safety glasses must always be worn when working with solutions (no matter how dilute or small they are).

4.      Gloves must always be worn when working with chemicals especially when working with HF no matter how dilute.

5.      All solutions must be properly labeled. This includes the chemical names, the date it was made and the person who made it.

6.      Copy all your data off the computer at the end of your run.

7.      No one is to do anything on the instrument computer while someone else is running samples. This can cause the computer to crash.

8.      All solutions and equipment used in the lab must be put away before you go home. This includes throwing away used kimiwipes and gloves. There should be no trace of you left in the lab.

 

Cone Cleaning

 

Cones should be cleaned before being put into the instrument. Dirty cones result in poor sensitivity.

 

Cones should first be scrubbed with polaris polishing powder, both the front and back of each cone. Be sure to gently scrub around the orifice of the cone. This is where sample build up occurs. When polishing the back of the cone, hold the cone in your hand. Never rest the cone upside down. If you damage the cone’s orifice, the cone will no longer work properly.

 

After polishing the cones thoroughly rinse them off with water. Use a squirt bottle to make sure the holes in the cones are not blocked.

Place cones in citranox solution and sonicate for 5-10 minutes.

 

Rinse all citranox solution from the cones. Once again use a squirt bottle to make sure the holes are clear.

 

Dry cones with kimiwipe before storing them or installing them into the instrument

 

Torch Glassware cleaning

 

All glassware should be cleaned in 8N HNO3. If is not needed immediately it can be left to soak in the 8N HNO3 for several days. If it is needed immediately the solution should be placed on a hotplate (in a hood) for 1 hour at sub-boiling.

 

If stains persist on the glassware from the Pt shield, the glassware can be cleaned in Aqua Regia. (Any work with Aqua Regia must be done in hood. Also Aqua Regia is very exothermic so never close a container with Aqua Regia in it.)

 

Rinse all acid off the glassware with clean water.

 

Let glassware dry completely. If you are in a rush to dry the glassware, you can place it in a drying oven. Make sure that the glassware does not get dirty from the oven. Never put a wet torch into the instrument. It will melt.

 

Aridus Cleaning

 

The Aridus should be cleaned after each usage. When cleaning the Aridus you should be wearing safety glasses, gloves and a lab coat. To clean the Aridus well all acids used should be warm. You can either heat up the acids used or you can clean the Aridus immediately after it has been turned off, so it is still warm.

 

Before any cleaning can occur:

The Aridus must be turned off and the unplugged.

All gas lines going into the Aridus must be closed.

 

All cleaning tubes must be connected to their properly labeled outlets. The stop plug that is normally screwed into the rinse when the Aridus is in use should be placed into the drain outlet. Be sure to have the waste tubing going into a waste container.

 

Fill squirt bottle with solution. Squeeze solution into the tubing. Once you get solution into the tubing you can open the cap to the squeeze bottle and let the acid siphon until the bottle is empty. After bottle is empty squeeze air through the bottle to push as much of the acid back out of the Aridus.

Repeat this procedure with the following acids.

1.      10% HNO3 + 5%HF

2.      10% HCl

3.      10% HNO3

4.      DI  or DD water

After cleaning is done, pull out the spray chamber and shake out any liquid in it. Put the spray chamber back in the Aridus. Place both the waste tubing and the bottle tubing into a waste container. Reconnect the drain tubing. Turn on the Aridus and open up the gas lines. Turn the gas flow up to 3-4L/min. Leave it on for a minimum of 30 minutes to push out any remaining solution in the Aridus. You may need to tilt the Aridus repeatedly to help get all the solution out.

 

The sensitivity will be low for a couple of days right after the cleaning as the tubings dry out. Leaving the aridus on with Neb gas turned high could help the dry down process.

 

Pre-lighting checklist

 

CONES

1.      Make sure you use the proper set of cones and that they are clean.

2.      To move the torch out of position go to the Instrument Control window, open the Source Tuning window and click on Retract Torch. Be sure to disconnect any tubing that doesn’t have enough slack to move with the torch.

3.      Before inserting the skimmer (little) cone check that the o-ring is in place

4.      Using the cone tool rotate the skimmer cone until it is hand tight. The threads on the skimmer cone are stripped, consequently it may be hard to screw the skimmer cone in place. If the skimmer cone does not make more than a full rotation, it is not really screwed in.

5.      Before inserting the sampler (big) cone make sure the graphite gasket is in place.

6.      With a gloved hand hold the sampler cone in place against the graphite gasket and then screw the holder in place over it. Do not let go of the sampler cone until the holder has secured it. Using the cone tool turn the holder so it is hand tight.

7.      Return torch to original position by clicking Position Torch in the Source Tuning window.

 

GLASSWARE

1.      All glassware should be in good condition. If the glassware has any cracks, devitrification, or buildup, it should be replaced.

2.      The torch should be lined up so the injector is 3-5mm behind the load coil. The Pt shield should be lined up with the load coil. The connection on the shield should be under the torch and pointing down towards the back of the torch. The bonnet should be covering the shield and be flush with the end of the torch.

3.      Make sure the gas lines to the torch are tight. The cool gas goes into the outer torch tube and the auxilary goes into the injector torch tube. The cool gas has the tesla connection attached to it. This is what sparks to start the plasma.

4.      If using the Aridus be sure the tubing from the Aridus is attached to the torch. Also the water lines for the spray chamber should have tubing looping them together. These are the water lines labeled SPRAY.

5.      If using a spray chamber, make sure the spray chamber in attached to the torch. Make sure the in and out spray chamber water lines are also attached. The water in should be connected to the bottlom of the spray chamber and the out to the top. This way air bubbles will not build up. These are the water lines labeled SPRAY.

6.      Make sure all waste containers are not going to overflow.

7.      Make sure all sample and waste tubing is in good condition. If not it must be replaced. Make sure all tubing is connected, especially the waste tubing. Make sure the waste tubing is pumping out into a waste container, and sample tubing is pumping into the nebulizer.

 

ARGON (and other gases used)

1.      Make sure the Argon dewar has enough Argon to run for the day. You don’t want the Axiom to turn off in the middle of a run. For the large liquid dewars, if you can shake/tip the tank, the Argon is getting low, and a new tank may need to be order. For the compressed gases, you need to check the pressure.

2.      Make sure the Argon dewar is at the proper pressure. The pressure on the tank must be at least 110psi to turn on.  Once the Axiom is on the pressure should be at 150psi. If the pressure is low, the pressure builder needs to be opened on the tank. Do not open this valve all the way or the tank will over pressurize and vent. You need to open the pressure valve just enough to keep the pressure on the tank between 150 and 200psi while running. If the tank’s pressure keeps increasing it will vent at 230psi or 350psi depending on the tank. When a tank vents, it’s wasting Argon.

3.      If you open the pressure builder, don’t forget it needs to be closed when you are done running. If the Axiom is not pulling off Argon and the pressure builder is open the tank will vent.

 

CHILLER

1.      Check that the water level is about 1 inch below the the top.

2.      Make sure the chiller is plugged into the CHILLER outlet on the Axiom.

3.      Make sure the chiller on/off switch is in the ON position.

4.      When the Axiom first turns on the chiller should turn on as well. If not you need to stop the startup immediately.

 

ARIDUS

1.      Make sure all the gas lines are connected and open.

2.      If using Nitrogen, make sure the Nitogen tank is open. This tank should be closed when not in use. The inlet tube should also be closed when not in use.

3.      Connect all pump tubing.

4.      Turn on power and make sure temperatures are set at the proper values. If using the FEP spray chamber, the spray chamber temperature should be at 70oC. If using the PFA spray chamber, the spray chamber temperature can be increased up to 100oC. If the FEP temperature is >70oC, you will melt the spray chamber. When in doubt keep the spray chamber temperature at 70oC. The desolvator temperature should always be at 160oC regardless of the spray chamber.

5.      Turn all gas flows down. Sweep gas should be less that 1L/min, and the N should be at 0mL/min. You cannot light the plasma if you are blowing gas into the torch.

 

STARTUP

1.      Make sure the Instrument Control window is open.

2.      Before starting open up the System Analyzer. Write down the pressures for the transfer, backing and analyzer on the log sheet.

3.      Click the On button. This will initiate the Axiom’s startup sequence. There are 6 stages.

Stage 1: The instrument is OFF Only the turbo pumps are on.

Stage 2: The cool gas and chiller turn on. Always double check that the chiller comes on.

Stage 3: The torch position is set to light. The auxilary gas turns on, and the Nebulizer gas is purged.

Stage 4: The Plasma is lit. The expansion pump turns on. The nebulizer gas turns on.

Stage 5: The slide valve opens.

Stage 6: The high voltage is on. The faraday zero is set, the analyzer voltages are set, and the slits are open.

            After stage 6 is completed, you must click Acknowledge.

            If any error occurs, the instrument will return to the lower safer state.

4.      Once the Axiom is on, several reading should be recorded on the log sheet. All of these reading can be found in the System Analyzer window. You must write down the pressures of the transfer, backing and analyzer. Write down the following readings. (40) Ion Energy should be below 1. (56) RF Reflective Power should be below 5. (57) RF Output should be around 1180.

5.      Load your appropriate settings. In Instrument Control Window click on File and then Load Settings. Select the settings you want and click OK. Then click on Options then Settings. Here you can enter the rest mass and hysteresis cycle.

6.      Load your collector configuration. In the Instrument Control Window click on Multi-Collector and then Collector Positions. Select the collector setting you want. It will take several minutes for the collectors to change position.  When loading the collector positions you may get a time out error. If you do click the Test Position Integrity.

7.      Open Mass Scan window. Select a mass you’d like to scan and set up a continuous scan across your mass range for the warmup. This scanning will help the magnet to warm up.

8.      Put the sample probe into an acid wash for the warmup. This will help to clean out the system during warm up. If using the spray chamber and pump tubing. You should put water through the probe first and see if all your connections are correct, before switching to acid. If using the Aridus bring the sweep gas flow up to around  2.5 L/ minute.

9.      Leave Axiom to warmup for 30 minutes.

 

Shutdown Procedure

 

1.      Aspirate acid through the nebulizer for 10-15 minutes to thoroughly clean out any remaining sample. Sample left in the tubing may cause blank problems for the next user.

2.      Aspirate MQ water for 1-2 minutes to clean acid out of the tubing. Acid will eat away and corrode the tubing over time.

3.      Aspirate air for 1-2 minutes to dry out the tubing. Yes even water will corrode tubing if left in there.

4.      Click the OFF button in the System Analyzer Window. Make sure the Axiom turns off completely. It must say State 1.

5.      Turn off all auxiliaries (Aridus, …).  Make sure waste tubing is empty before turning off any peripumps.

6.      Unhook all pump tubing. Leaving pump tubing tight will stretch it out and then it will have to be replaced for the next user.

7.      If you used the Aridus close the gas lines leading into it.

8.      If you opened the pressure builder on the Argon tank make sure it is closed when you are done, otherwise pressure will continue to build with nothing pulling off the Argon and the tank will vent until it’s empty.

9.      Close all other gas cylinder you opened.

10. Load the default settings back on the Axiom. Make sure the rest mass is at 85.

11. Load the default cup configurations. If you leave the cups close together for a long time you will damage them.

12. Pull your data off the computer before you leave.

13.  CLEAN UP YOUR MESS. THERE SHOULD BE NO TRACE OF YOU LEFT IN THE LAB AFTER YOU ARE DONE.

 

Axiom notes by Merry Cai

 

Step 1. Turn on the machine

 

Turn on the computer, you want to enter OS-2 interface. To get to the control panel, click the magnet on the top bar.

 

Find sign-up sheet, go over the prelighting check list.

 

Make sure the shields are in place on the torch…pay attention to the pink wire under the torch, it should never touch anything around, otherwise there will be shorts, burns, etc.

 

Check connection of the sample introduction tubing (the one fitted with 2 clips).

 

Check chiller water level, and check that it’s plugged into the back of the machine.

 

Check cones, if it’s very dirty, clean it with citrinox solution (2%). Sonicate with solution (15 min), use aluminum powder to polish it if needed, sonicate with DI water (10 min), then sonicate with IPA (3 min), then put them back in.  DON’T ATTEMPT IT WITHOUT SUPERVISION FIRST.

 

Open the valve for Ar gas (2 valves).

 

Check the waste container behind the Aridus, hook up the waste tubing (check the directions of the tubing). Turn on the Aridus unit.

 

Write down the pressures. Turn on the machine.

 

Once the machine is on (make sure it goes through all the stages until stage 6, about 10 minutes). On instrument control, click “mass scan”, set the centre mass to the mass of interest, Collector should be on MF position, run “baseline” first (zero ion energy).

 

With “SIM” mode, click “Start” to measure the peak mass. (To check the peak shape and location of the peak center, use “Scan” mode.

 

You want to make sure that the correct collectors positions are loaded and use the right user setting. To change collector position, go to “Multi-collector”, click “collector position”. “Open” and select a setting under the “collector positions” window. If the program sends error message “unknown position”, it’s probably because of communication error, so use “check collector integrity”.

 

Load your own setting under “File”, “Load setting” etc.

 

Then you are ready to tune up a standard.

 

 

Step 2. Tune up the machine

 

Back flush the sample introduction tubing (sample tubing) in case something dried up in the line. To do that, put the sample introduction tubing in the backwash solution. Take out the nebulizer, use a piece of parafilm to cover it tightly so that the Ar gas back flushes out until you see bubbles coming out from the sample introduction tubing vigorously. Take the tubing out of the backwash solution before you uncover the nebulizer so that the solids that might be in the backwash solution do not re-enter the tubing and cause it to clog again.

 

Insert the sample tubing in clean wash (often 3% HNO3 solution, or some times with trace amount of HF), make sure the tubing is taking in solution by observing air bubbles going through the tubing. You can also check the intake by holding the nebulizer against a piece of kimwipe and observe if mist wets the wipe.

 

After initial washout, we can then take in some standards with known concentration and tune up the settings.

 

(1) Sweep gas setting (currently optimal around 3.09, it varies depending on Ar pressure)

(2) Source tuning, check torch position, only change the X and Y position. Z should remain at 190. The optimal position is achieved when the sensitivity decreases roughly the same amount when you decrease/increase the setting by the same number of steps.

 

I usually leave the gas settings alone. But if necessary, change the Neb gas one step at a time and wait for 1 minute for any change to happen because there is a lag time for gas settings to take effect.

 

(3) Beam tuning: tune the transfer lens, x deflect and y deflect. X lens setting will change the peak shape and peak center, so only tune it when the peak shape is bad in the beginning. Tuning it during the run will change standard values.

 

(4) Wash out the system and get ready to run 10-20 standard runs. Check the standard deviation and the external reproducibility of the standards.

 

(5) Run sample: samples need to be corrected for cup efficiency by taking into account of the difference between published and measured standard values.

 

Running Hf on the Axiom

 

Rinse with HNO3 and HF mixture, external error < 40ppm.

 

Running Nd on the Axiom

 

Rinse with HNO3, external error < 40ppm.

 

Running Pb on the Axiom

 

Last ran March 19,2009

First step we need to find out the exact concentration of Pb in the samples. Run a different file…. Measure the standard a few times then diluted samples…. Need to ask louise for confirmation next time I run.

 

Tl 205 on Axial, monitor Tl for peak (use low resolution for tuning, high resolution for monitoring the peak (minimum 0.2 amu width at 550 resolution). Change the cup setting to Tl205 on Ax, if the cups do not seem to automatically move to position, use “check cup integrity” function.

 

150 ppb Pb 981 solution had 27.75 ppb of Tl in it and gave 1.6 volts signal on 205. For both standards and samples, we need to add Tl proportional to the amount of Pb in the solution. For every 200ppb Pb, there should be 37ppb Tl.

 

After solutions are made, we need to make sure the system is clean of Pb (monitor H3). To wash out Pb, we use a series of acids

           

  1. 3% HNO3
  2. 6N HCL
  3. 8N HNO3
  4. WATER
  5. 50% IPA
  6. WATER
  7. 6N HCL
  8. 8N HNO3
  9. 3% CLEAN HNO3

 

For each step of the wash, monitor the signal till it stabilizes with  no significant peaks appear.

 

To measure samples, disable the “automatic peak center” function to speed up the process. Then run the sample 5 times (takes ~1ml solution). The optimal intensity range for 205 Tl is 1.5-2.0 volts.

 

To double check results, 203 Pb should be an order of magnitude higher than the first value measured…

 

Standard reproducibility should be lower than 200ppm for all three ratios.

 

Running Li on the Axiom