Ultrasonic slurry sampling

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  

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

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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. 

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. 

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... 

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. 

H. Matusiewicz and M. Mroczkowska, Hydride generation from slurry samples after ultrasonication and ozonation for the direct determination of trace amounts of As (III) and total inorganic arsenic by their in situ trapping followed by graphite furnace atomic absorption spectrometry, J. Anal. At. Spectrom., 18, 2003, 751-761. 

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. 

Analyzer Q = quadrupole, CC = collision cell, DRC = dynamic reaction cell, MC = multicollector, SF = sector field. Analytical details CV = cold vapor, ETV = electro-thermal vaporization, FI = flow injection, HG = hydride generation, ID = isotope dilution, LA = laser ablation, UN = ultrasonic nebulization. Sample introduction in liquid or slurry (si) form. 

The effect of ultrasonic treatment on com particles was examined by sonicating both cooked and raw corn slurry samples and the resulting particle size was compared with nonsonicated samples (controls). The peak of the particle size distribution curve shifted from 800 pm to around 80 pm following sonication at high-power levels for cooked corn slurry samples. In addition, the particle size reduction was directly related to the power level and sonication time. The particle size reduction at the... 

The importance of sample delivery is frequently overlooked in the studies on acoustic levitation, even though precision in the analyses relies heavily on an appropriate choice of the sample volume. Delivery systems are closely related to the nature of the sample (liquid, suspension, solid or gas). Any type of system e.g. a micropipette, capillary, or microsyringe) can be used to position a drop from a liquid or slurry sample in an ultrasonic Ievitator. 

Ultrasounds have been used to assist in the insertion of samples into solid-liquid analytical systems for some time. The earliest ultrasonic nebulizers and automatic slurry sampling systems were reported in the 1980s. However, the actual potential of ultrasounds for increasing the efficiency of sampling systems remains to be explored. Thus, a recently developed technique based on acoustic levitation has been found to substantially... 

Miller-Ihli N. J. (1989) Automated ultrasonic mixing accessory for slurry sampling into a graphite furnace atomic absorption spectrometer, J Anal At Spectrom 4 295-297. 

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