Do Not Handle unless you are sure that the nebulizer is dry, or washed with clean water. Acids, particularly HF, often look like water and will wet the end of the nebulizer during usage.
This device operates on compressed gases. Appropriate care must be taken. If in doubt about correct operating procedures, call an experienced operator or a Thermo Elemental Applications Scientist.
Your Thermo Plasma Spectrometer is designed to supply a maximum pressure to the nebulizer of 45 psi (3.2 kg/m2). Under no circumstances should this nebulizer be connected directly to a gas line or supply source other than the nebulizer supply connection in your TJA Plasma Spectrometer, using the attached Luer-Lok fitting.
The gas orifice is at the very tip of the nebulizer. It is machined directly in the Teflon® body which is VERY SOFT. This tip is very easily damaged and should NEVER be touched with fingers, tissues, or anything else. If the tip is accidentally touched, and the nebulizer continues to operate, then it is still functional, and its use can be safely continued.
2. Dropping and Breakage
The Burgener Nebulizer body is 100% Teflon® . Generally it will not break. If it is dropped such that the tip is deformed, then it will be irreparably damaged. If it continues to operate after being dropped, then it has not been affected, and its use can be safely continued.
Your new Burgener Nebulizer is unique. It should give you a long and convenient service on almost any liquid you can pump to it. The operation and care of your nebulizer is different from glass nebulizers in several important ways.
1. Washing Your Nebulizer:
Please DO NOT wash your nebulizer in acid or solvents to 'prevent salt build up'. Teflon® does not wet, so salts do not build up. For the longest life and best performance, wash your nebulizer by simply running water as a sample for 10 minutes at the end of the day before shutting down the plasma. Any other form of washing is excessive, unnecessary, of no advantage, and often detrimental. DO NOT remove the filter in the back of the nebulizer under any circumstance. DO NOT immerse the nebulizer completely in any liquid (water, acid, or any other solvent). It would cause saturation of the filter plug and plugging of the gas orifice.
2. Humidified Argon:
The Burgener Nebulizer is 100 % Teflon® . Teflon® does not wet, so salts do not begin to form at the gas orifice. This allows you to run high salts without the tip plugging. However, if high concentrations of salts are being analyzed, it may be necessary to humidify the argon to prevent plugging of the torch injector tube.
3. Using Surfactants:
Teflon® does not wet. This causes a slight pulsation in the nebulizer's output, related to the pump's pulsation. DO NOT soak the nebulizer in surfactants to decrease the pulsing. You may appear to succeed, but the surfactant will also allow salts to form at the gas orifice, and result in plugging the orifice. The pulsation is generally well averaged out in the mixing chamber as the aerosol travels to the torch. A surge suppressor is supplied. This is simply a larger diameter tube, about 1 cm in length, which is placed in the line. It is generally found to be unnecessary, due to the relatively long integration times used on the ICAP 61E Trace and IRIS AP. However, it may offer some improvement on the TraceScan due to the shorter integration times used on the sequential system.
4. Sample Uptake:
The Burgener Nebulizer produces optimal aerosol with an uptake rate of approximately 2 mL/minute of sample flow. This is achieved with a peristaltic pump speed of 130 to 140 rpm, with the Tygon Orange/Orange tubing. Also, at this pump speed, the effects of pulsing discussed earlier (section 3) will be minimized.
5. Nebulizer Pressure:
The Burgener Nebulizer operates optimally at pressures between 25 and 35 psi. The exact pressure depends on the nebulizer, as well as the type of center tube being used in the plasma torch. Each nebulizer must be tested by looking for the pressure which gives optimum precision. This will generally be found to be a narrow range of 1 to 2 psi. An initial pressure can generally be found by observing the central channel of the plasma while aspirating a solution of 1,000 ppm Y. Adjust the pressure until the red tongue is just level with the upper turn of the work coil. This is easy to observe with a relatively new torch, but, once the torch becomes discolored, it may be difficult to see this tongue. In this case, there is little alternative but to begin at 25 psi and increase at 2 psi intervals until the best precision is found. At the optimum pressure, precision on an ICAP 61E Trace should be around 0.5% for 1 ppm of most of the elements in the QC-19 Test Solution.
6. Nebulizer Orientation:
Some nebulizers are sensitive to orientation. The normally correct orientation is with the capillary tube extending from the body facing upward. However, some nebulizers have been found to give better performance when this capillary tube faces downward. Be sure to check orientation, once the apparently optimum nebulizer pressure has been found to determine which gives the better results.
Changing the Tygon Gas Tubing
The Burgener Trace Nebulizer comes with the Tygon gas line attached. Generally, it should not need replacing.
To Replace the Tygon Gas Tubing:
1. Cut off the old gas line with a very sharp knife such as an exacto knife. DO NOT touch the Teflon® with the knife blade. Cutting the Teflon® will l severely weaken the barb ending of the nebulizer. Do not try to pull off the Tygon tubing without cutting the portion over the barb. Teflon® can be stretched or broken with such pulling forces.
2. Slightly moisten the barb on the rear of the nebulizer. Do Not let the filter get wet.
3. Push the new Tygon tubing on by hand. This is Very Difficult. Push it on at least half way between the rear of the main body of the nebulizer and the widest edge of the barb.
Do Not Heat the Tygon to Soften it
and allow for an easier push. Heating Tygon will permanently soften the Tygon, and it will creep off or pop off the nebulizer when pressure is applied.
How to replace the capillary tubing:
Clearing and Replacing the Capillary Tubing
The Burgener Nebulizer is designed with the Patented Enhanced Parallel Path configuration. The only portion of the sample path that is actually part of the nebulizer is at the tip. It will not plug with dust or sand or other tiny particles. However, the capillary tubing may occasionally plug. Generally, the capillary tubing plugs at the joint between the pump tubing and the capillary tubing. To clear such a plug, just cut off 1 mm of the capillary tubing closest to the pump, and use it again. For plugs in the middle of the tubing, or eventually, if the tubing is getting too short, you will have to replace the capillary tubing.
TO REPLACE THE CAPILLARY TUBING:
1. Pull out the old capillary tubing. It is just held in place by tension.
2. Take a piece of new tubing, e.g. Polyethylene Tubing, with O.D. 1.09 mm (0.043 "); I.D. .38 mm (0.015 "). Measure out the desired length (About 15 " or 38 cm).
3. Wrap it around your fingers and stretch out about 4 inches to about 1/2 its original diameter.
4. Push the stretched portion through the Nebulizer's sample path until it extends out past the end of the nebulizer. Use the stretched portion to pull unstretched tubing past the tip of the nebulizer.
5. Cut off the stretched portion. Pull back the unstretched portion, until the tubing is recessed about .25 " (about 6 mm) from the tip. The distance of the recess is not critical, as long as it is about .25 " or more.