Microconcentric nebulizer

The dimensions of concentric-tube nebulizers have been reduced to give microconcentric nebulizers (MCN), which can also be made from acid-resistant material. Sample uptake with these microbore sprayers is only about 50 xl/min, yet they provide such good sample-transfer efficiencies that they have a performance comparable with other pneumatic nebulizers, which consume about 1 ml/min of sample. Careful alignment of the ends of the concentric capillary tubes (the nozzle)... 

Vanhaecke F, Van Holderbeke M, Moens L, Dams R (1996) Evaluation of a conunercially available microconcentric nebulizer for inductively coupled plasma mass spectrometiy. J Anal At Spectrom 11 543-548... 

Samples were prepared for Cu isotope analysis on the Multicollector Inductively-Coupled Plasma Mass Spectrometer (MC-ICPMS) at University of Arizona. The Cu-rich samples were loaded and dissolved in pure HNO3 and the Cu-poor samples were loaded and dissolved in a mixture of HCI and HNO3, Chromatographic separation of the Fe and Cu ions was deemed necessary for the Cu-rich samples. The diluted solutions were injected into the MC-ICPMS using a microconcentric nebulizer. Samples were run numerous times to increase precision. The Cu isotope ratios are reported in conventional per mil notation, relative to the NIST 976 standard. Mass bias was also accounted for by bracketing methods with the NIST 976 standard. 

The samples purified with lEC were diluted to approximately 100 ppb Cu. These samples were injected into a Multicollector Inductively-Coupled-Plasma mass spectrometer (MC-ICPMS, Micromass Isoprobe at the University of Arizona and Neptune at Washington State University) in low resolution mode using a microconcentric nebulizer to increase sensitivity for the samples with lower concentrations of copper. The nebulizer flow was adjusted so that the intensity of the Cu beam remained constant at 2 volts. Both on and off peak blank corrections were applied to the data and yielded the same result. 

Figure 5.1 Main parts of an inductively coupled plasma mass spectrometer sample introduction systems (left column), e.g., Meinhard or MicroMist nebulizer with cyclonic spray chamber, ultrasonic nebulizer, microconcentric nebulizer and laser ablation system (all from CETAC Technologies), ion source (middle column) and several types of mass spectrometers, (a) Agilent 7500 from Agilent, (b) Platform from CV Instruments, or (c) Element from Thermo Fisher Scientific. (Parts of this figure were reproduced with permission from CETAC Technologies, Agilent, CV Instruments and Thermo Tisher Scientific, respectively.)...

Figure 5.14 Schematics a) of DIHEN (j.E. Meinhard Associates, Santa Ana, CA) ().S. Becker, H.J. Dietze, ].A. McLean and A. Montaser, Anal. Chem., 71, 3077 (1999). Produced by permission of American Chemical Society) and b) of microconcentric nebulizer (MCN 100, CETAC Technologies, Ohama. Reproduced by permission of CETAC Technologies)...

A frequently used micronebulizer with heated spray chamber and membrane desolvator is the Aridus from CETAC Technologies, Ohama, NE. The experimental setup of the Aridus II microconcentric nebulizer is shown in Figure 5.16. 

Figure 5.16 Schematic of microconcentric nebulizer (Aridus II, CETAC Technologies, Ohama). (Reproduced by permission of CETAC Technologies.)...

V.V-dicthyl-V -bcnzoy I thiourea (DEBT). The palladium complex formed was eluted with methanol and introduced into an ICP-SFMS via microconcentric nebulization with membrane desolvation. Isotope dilution analysis was employed for quantification purposes.80... 

Amselfelder red wine from Kosovo has been investigated with respect to uranium and plutonium content using ICP-SFMS (Element). The microconcentric nebulizer Aridus (Cetac Technologies) was applied for solution introduction into the ICP source. In different red wine samples, uranium with a natural isotopic composition was found at a concentration of 0.145 0.011 Jigl-1, which corresponds to the normal uranium background concentration. Plutonium was not detected at a detection limit of 10-5p,gl-1.36... 

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

Figure 9 Ratio of tertiary to primary aerosol volume as a function of drop size for different sample uptake rates. A Cetac microconcentric nebulizer (MCN) was used in a double-pass spray chamber. Other concentric nebulizers behave similarly. (From Ref. 422.)...

M. De Wit, R. Blust, Determination of metals in saline and biological matrices by axial inductively coupled plasma atomic emission spectrometry using microconcentric nebulization, J. Anal. Atom. Spectrom., 13 (1998), 515-520. 

ICP-MS is a multi-element technique suitable for the analysis of liquid samples, which provides higher selectivity and detection power and LoDs lower than other multi-element techniques, such as ICP-AES. These characteristics make ICP-MS an excellent tool for the detailed characterization of the elemental composition of beverages. In this context, ICP-MS was the technique selected for the determination of 31 trace elements in wine at concentrations ranging from 0.1 to 0.5 ng ml-1 [82]. Samples were diluted 1 + 1 and it was investigated whether a matrix effect derived from the presence of ethanol could be overcome by using a microconcentric nebulizer with membrane desolvation. The authors compared their results with those obtained using a conventional Meinhard nebulizer and concluded that the matrix effect observed could only be minimized by using an internal standard with the Meinhard nebulizer, but not with the other one. 

A suitable calibration strategy has been demonstrated for the determination of selected elements, i.e., Pb, Ag and T1 in a small amount of platinum nanoclusters. In on line isotope dilution analysis with LA-ICP-MS, an isotope emiched tracer solution was nebulized by the Aridus microconcentric nebulizer with desolvator. After about 180 seconds, laser ablation of the investigated platinum nanocluster sample was started and after an additional time of 180 seconds 2 % nitric acid nebulized instead of the tracer solution. The isotope ratios of lead ( Pb/ ° Pb), silver ( ° Ag/ ° Ag) and thallium ( ° T1/ ° T1) - with Cu/ Cu for internal standardization - were monitored during the whole experiment. The measuring time for one experiment was <10 min. 

A method for the accurate online ultratrace analysis of palladium in environmental samples (road dust and contaminated soil samples) by ICP-MS after separation of interferent cations by cation exchange chromatography was introduced by Hann and co-workers. ° Palladium was selectively adsorbed online onto a Cjg microcolumn which had been reversibly loaded with a complexing agent A,Al-diethyl-Al -benzoylthiourea (DEBT). The palladium complex formed was eluted with methanol and introduced into an ICP-SFMS via microconcentric nebulization with membrane desolvation. Isotope dilution analysis was employed for quantification purposes. ... 

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