High-pressure nebulizers

The speciation of Cr (III) and Cr (VI) has been performed by Jakubowski et al. [22] with IPC-ICP-MS and hydraulic high-pressure nebulization. A mobile phase of 25% methanol, ammonium acetate, and an ion-pair reagent (tetrabuty-lammonium acetate) was used. Oxygen addition was used to reduce carbon interferences from the high organic content in the mobile phase, along with desolvation. 

Several cfPcicnt sample introduction systems have been conceived to achieve higher precision, accuracy, and sensitivity, such as thermospray nebulization (TN) [95], ETV [88, 99], and hydraulic high pressure nebulization. The use of desolva-tation devices, for example, ultrasonic nebulization (UN), in combination with... 

E. Puskel, Z. Mester, P. Fodor, Determination of selenoamino acids by high-performance liquid chromatography-hydraulic high pressure nebulization-atomic fluorescence spectrometry, J. Anal. Atom. Spectrom., 14 (1999), 973-976. 

Commercial yeast-based supplements Hot water extraction IP HPLC-ICP-MS with hexapole collision and reaction cell, hydraulic high pressure nebulizer... 

In addition, for speciation coupling of flow injection analysis and column chromatography with flame AAS and also a direct coupling of HPLC with flame AAS, as is possible with high-pressure nebulization, are most powerful. Here the Cr line in the visible region can be used, which makes the application of diode laser atomic absorption spectrometry possible [325]. This has been shown recently by the example of the determination of methylcyclopentadienyl manganese tricarbonyl. 

It should be kept in mind that both thermospray nebulization and high-pressure nebulization [143] successfully allow the analyte introduction efficiency to be increased and thus also the power of detection, however, again only when aerosol desolvation is applied. They are especially interesting for speciation by on-line coupling of ICP-AES and HPLC, as shown later. 

Gas and liquid chromatography Coupled with ICP-AES these are useful approaches for speciation work, as shown by the early work of Cox et al. [418] for Crm/Crvl speciation, where AI2O3 filled columns and elution with acids and NaOH were used. Anion exchangers could also be used. New impetus has arisen from the interfacing of thermospray and high-pressure nebulization to ICP-AES. ICP-AES remains of interest for the element-specific detection in the speciation of silicon compounds and is a good alternative to ICP-MS, where considerable spectral interferences hamper the power of detection that can be obtained. 

Berndt H. (1988) High-pressure nebulization a new way of sample introduction for atomic spectroscopy, Fresenius J Anal Chem 331 321-323. 

Posta J. and Berndt H. (1992) A high-performance flow/hydraulic high pressure nebulization system (HPF/ HHPN) in flame AAS for improved elemental trace determinations in highly concentrated salt solutions, Spectrochim Acta, Part B 47 993-999. 

Berndt H. and Yanez J. (1996) High-temperature hydraulic high-pressure nebulization a recent nebulization principle for sample introduction, J Anal At Spectrom 11 703-712. 

Jakubowski N., Jepkens B., Stuwer D. and Berndt H. (1994) Spedation analysis of chromium by inductively coupled plasma mass spectrometry with hydraulic high pressure nebulization, J Anal At Spectrom 9 193-198. 

HG-OES hydride generation optical emission spectrometry (see HG-AES) HGPRT-test hypoxanthine-guanine-phos-pho-ribosyl-transferase test, a mutagenicity test with mammalian cells HHPN hydraulic high pressure nebulizer HIV human immunodeficiency virus HMDE hanging mercury drop electrode... 

A low liquid flow rate is essential for lower oxide and other polyatomic interference formation, so a low-flow, high-pressure nebulizer made of PP or PFA is necessary. Self-aspiration with an Elemental Scientiflc PFA-ST, one piece nebulizer with 0.25-mm internal diameter (i.d.) (approximately 100 pL/min) uptake tube and probe has been used for this purpose to eliminate liquid surging in the plasma that results from peristaltic pumping. An equivalent low-flow nebulizer may be used. 

Fig. 48. ICP-MS coupled on-line to liquid chromatography using hydraulic high-pressure nebulization. (1) HPLC pump, (2) sample loop, (3) chromatographic column, (4) ...

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