by Ryan Brennan, Jerry Dulude and Vesna Dolic AL
Argon Humidifier Provides Uninterrupted, Maintenance-Free ICP Operation
Dry argon is used as an ICP nebulizer gas to gen- erate an aerosol and transport the sample to the plasma. However, samples containing high amounts of total dissolved solids (TDS) increase the likelihood of salt deposits forming at the tip of the nebulizer and injector, which can result in a failed analysis due to a drift in signal or an extinguished plasma. In order to handle a chal- lenging sample matrix like one high in TDS, it is important to optimize the inductively coupled plasma (ICP) sample introduction system. This includes choosing a nebulizer with the ability to handle high TDS, a baffled cyclonic spray cham- ber to minimize droplet size and a large-bore injector to allow for longer run times. For best performance, the nebulizer gas can be humidi- fied before it comes in contact with the sample, decreasing the likelihood of salt deposits form- ing at the nebulizer and injector tip. Adding an
argon humidifier will reduce maintenance and the chance of an extinguished plasma due to a blocked nebulizer or injector.
The Elegra argon humidifier (see Figure 1) (Glass Expansion, Pocasset, Mass.) is an efficient, simple-to-use humidifier for ICP-OES (optical emission spectrometry) and ICP-MS (mass spectrometry) applications. A small footprint enables it to fit easily into an ICP without over- crowding the sample compartment. Highly efficient membrane technology is utilized to add moisture to the gas as it flows through the inert, metal-free construction. This membrane technology eliminates the need for the Elegra to be pressurized or heated (no electrical power), as required by some other humidifier designs. A unique bypass switch permits the operator
a b
to turn humidification on and off without con- necting or disconnecting any tubing.
For easy installation on any ICP instrument and with any nebulizer, each Elegra kit is packaged with customized gas connectors. Figure 2 shows an example installation on an Agilent 5100 ICP-OES (Agilent Technologies, Palo Alto, Calif.) with Glass Expansion’s SeaSpray and DuraMist nebulizers. The layout of the gas connections to and from the humidifier is shown in Figure 2a. P/N 70-803-0911 is used to make the con- nection from the Agilent 5100 nebulizer gas port directly to the Elegra gas inlet (Figure 2b). A second gas line is used to make the connection from the Elegra outlet directly to the nebulizer. This is P/N 70-803-1278 for the DuraMist nebulizer or P/N 70-803-0911 for the
c
Figure 1 – Elegra argon humidifier.
Figure 2 – Elegra installation on an Agilent 5100 ICP-OES. AMERICAN LABORATORY 10 APRIL 2016
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52