Nebulizer high efficiency

Becker JS, Dietze H-J, McClean JA, Montaser A (1999) Ultratrace and isotope analysis of long-hved radionuclides by inductively coupled plasma quadrupole mass spectrometry using a direct injection high efficiency nebulizer. Anal Chem 71 3077-3984... 

Walder AJ, Roller D, Reed NM, Hutton RC, Freedman PA (1993) Isotope ratio measurement by inductively coupled plasma multiple collector mass spectrometry incorporating a high efficiency nebulization system. J Anal At Spectrom 8 1037-1041... 

The development of new, highly efficient nebulizers, described in detail in the section on ICP-OES (Section 12.2.4.4.1), has meant that a more concentrated aerosol and a more sensitive FAAS determination is achievable. Similarly, the use of slotted tube atom traps (STATs) and water-cooled atom traps (WCAT)10 11—the latter have undergone modification in recent years12—enhances sensitivity with regard to volatile elements like Cd and Pb because of the long residence time of these atoms in the tube. 

Singh J, McLean JA, Pritchard DE, et al. 1998b. Sensitive quantitation of chromium-DNA adducts by inductively coupled plasma mass spectrometry with a direct injection high-efficiency nebulizer. Toxicological Sciences 46 260-265. 

Figure 5 Micronebulizers (a) Meinhard high-efficiency nebulizer (HEN), (b) Cetac microconcentric nebulizer (MCN).

As can be seen from the results in Table 3.1, the analyte transport efficiency is similar for both conventional and micro- or high-efficiency nebulizers when compared under identical flow rates. The increase in analyte transport efficiency with decrease in the sample uptake rate (sometimes called starving the nebulizer because uptake rates less than the natural aspiration rate are used) was reported long ago [21,22]. So the main advantage of the newer micronebulizers is that their internal volume is small, a feature that becomes more important as the uptake rate is reduced. A capillary can also be inserted into a conventional concentric, pneumatic nebulizer to decrease its internal dead volume [23,24]. 

The second type of direct injection nebulizer, called the direct injection high-efficiency nebulizer (DIHEN), is a specific type of the Meinhard HEN [38] that is inserted into the ICP torch in place of the center, injector tube. The main advantage of the DIHEN compared to the Cetac DEN is that a high-pressure pump is not needed to deliver sample to the nebulizer. An unusually low nebulizer gas flow rate (0.25 L/min) and high ICP power (1.5 kW) were found to provide optimal ICP-MS sensitivity when DIHEN is used [38]. 

The potential of CE-ICP-MS for use in speciation studies offers the analyst a useful alternative for the separation of compounds of environmental and clinical importance. Detection limits for CE-ICP-MS are often superior to those achieved with traditional detection methods such as refractive index and uv spectroscopy. The use of low-flow nebulizers, such as the direct injection nebulizer and the high-efficiency nebulizer, which can accommodate the low electroosmotic flow of CE, offers significant advantages in terms of improved sensitivity. 

A type of concentric glass nebulizer which is operated at pressures of several tens of bars is known as a high efficiency nebulizer (HEN) [110]. More recently micro-... 

The addition of oxygen was found to be helpful when nebulizing effluents from HPLC containing organic eluents such as acetonitrile. This was useful when using ICP-MS for on-line detection in speciation as well as in trace-matrix separations. Here, however, it is useful to use desolvation, even in the case of low consumption, high efficiency nebulizers, such as the HEN or DIHEN. This can be done efficiently with membrane desolvation using Nafion membranes [148]. 

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