Ultrasonic slurry

Klemm W, Baumeach G (1995) Trace element determination in contaminated sediments and soils by ultrasonic slurry sampling and Zeeman graphite furnace atomic absorption spectrometry. Fresenius J Anal Chem 353 12-15. 

Multi-element analysis by ETV-ICP-MS using ultrasonic slurry sampling of silicon based minerals such as talc or quartz is described by Rodriguez et al.33 The calibration was performed in the standard addition mode, where slurries were spiked with different weights (volumes) of a multi-element standard solution of the analytes of interest.33... 

M. J. Cal-Prieto, A. Carlosena, J. M. Andrade, S. Muniategui, P. Lopez-Mahia and D. Prada, Study of chemical modifiers for the direct determination of antimony in soils and sediments by ultrasonic slurry sampling-ETAAS with D2 compensation, At. Spectrosc., 21(3), 2000, 93-99. 

Preparation of an ultrasonic slurry of the sample is occasionally used, as for example in the determination of cobalt, nickel and copper [200], selenium [39] and arsenic and antimony [40]. Extraction of leaves with a chloroform solution of xanthate completely extracted cadmium [41,103]. X-ray fluorescence spectroscopy is a nondestructive method of analysing plant materials if they can be converted into a suitable form for presentation to the instrument. 

Cobalt, Nickel, Copper Plants Ultrasonic slurry sampling, electrothermal AAS [85]... 

Solid foods in powder form can be analyzed directly by means of LA- or ETV-ICP-MS to eliminate time-consuming sample dissolution procedures (see Table 8.2). However, this requires the preparation of homogeneous powdered samples and the subsequent analytical determination is not as straightforward as the one based on liquid sample introduction. Another way to perform direct analysis of solid foods is to grind and suspend them into slurries. The viability of slurry nebulization relies on the ability to prepare samples of fine particle size in a reproducible manner and on the adoption of suitable (e.g., high-solids) nebulizers. Otherwise, slurries can be analyzed by ETV-ICP-MS resorting to the ultrasonic slurry sampling technique [72-74]. 

Some contradictory results are obtained in the comparison of results in the determination of arsenic after ultrasonic slurry sampling — the use of sampling is not most appropriate in this case as the sampling step is before the slurry formation — ultrasound-assisted extraction — leaching has been the correct word in this case — and microwave-assisted digestion [28], which will be treated in detail in Chapter 5. 

Ultrasonic slurry formation has been frequently used prior to cold-vapour and hydride generation. Both procedures usually involve a drastic treatment of the slurry to ensure complete transfer of the target species to the liquid phase for subsequent formation of the gas phase — after a normally long standing time — which is the only phase reaching the atomizer in the case of hydride generation and the detection point in the case of mercury vapour formation. The gaseous analytes or their hydrides are most often obtained in a commercial or laboratory-made dynamic flow injection manifold. 

Two particularly important considerations in ultrasonic slurry GF-AAS are that method development and optimization can be based on conventional liquid sample protocols and that, frequently, only limited changes are needed to facilitate direct insertion of solids. The recommended overall procedure for ultrasonic slurry GF-AAS determinations [101] involves six steps that are conducted in the following sequence ... 

Fig. 3.13, The USS-800 Ultrasonic Slurry Sampler. (Reproduced with permission of Perkin-Elmer Corporation.)...

Ultrasonic slurry mixing. The power output to the ultrasonic probe should be adjusted to provide good mixing (typically 40-80%). The usual mixing time is in the region of 20-25 s. 

Ultrasonic slurry sampling is also discussed in Chapter 8 alongside other modes of solid sample insertion into atomic spectrometers. 

RESULTS OF THE ULTRASONIC SLURRY SAMPLING ETA-AAS DETERMINATION OF Co, Ni AND Cu IN PLANT PARTS AND OLEA LEAVES CRM, WITH INCREASING GRINDING TIMES N=5 (DIFFERENT SLURRY PREPARATIONS). THE CERTIFIED OR INDICATIVE VALUE FOR THE CRM IS GIVEN IN BRACKETS... 

Gregoire, D. C., Miller-lhli, N. J., and Sturgeon, R. E. (1994). Direct analysis of solids by ultrasonic slurry electrothermal vaporization inductively coupled plasma mass spectrometry. /. Anal. At. Spectrom. 9(5), 605. 

Miller-lhli, N. J. and Baker, S. A. (2001) Microhomogeneity assessments using ultrasonic slurry sampling coupled with electrothermal vaporization isotope dilution inductively coupled plasma mass spectrometry. Spectrochim. Acta B, 56,1673-86. 

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