Drying of samples

Drying procedures found in the cited literature, (ly lyophilized t.c.w. to constant 

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Tissues Freeze drying of samples subjection to thermal neutron irradiation chemical separation of elements NAA No data No data Hewitt 1988... 

Soil Drying of sample and sieving forXRF digestion of sieved XRF No data 65-98 Krueger and Duguay... 

Soil Drying of sample, dry ashing, digestion with acid, and dilution with water AAS 2 pg/g 79-103 Beyer and Cromartie 1987... 

The solvents used for extracting isoflavones from soy foods were chosen according to the solubility of isoflavones and the food matrix involved. The diversity of soy isoflavones in polarity requires the use of a combination of organic solvent and water for extraction. The organic-to-water ratio (10 5) was established based on Murphy s study on solvent selection (Murphy et al., 2002). Water content in the solvent needs to be adjusted according to the moisture content in soy foods. Freeze-drying of samples before extraction simplifies the extraction process, but is not a prerequisite. 

There have been a variety of uses of microwave ovens in the laboratory these include the processing of ceramics, development of various plastics, catalysis, and acid dissolution of various materials.3 One developing use of microwave ovens is the drying of samples for weighing.3-6... 

The exact time required for drying of samples needs to be determined for each type of microwave oven being used due to the varying power (watts) of each type. It was demonstrated that it is possible to inadvertently melt borosilicate glass in a... 

B. Maichin, P. Kettisch, G. Knapp, Investigation of microwave assisted drying of samples and evaporation of aqueous solutions in trace element analysis, Fresenius J. Anal. Chem., 366 (2000) 26-29. 

Physostigmine salicylate in 0.5 % aqueous solution was determined by Teare and Borst by freeze-drying of samples of 0.2 ml, and conversion of the compound into its trimethyl silyl derivative by dissolving the residue in 5 yl of dry pyridine and 10 yl of N,0-bis(trimethyl -silyl)acetamide. The solution was allowed to stand for 1 h before injecting 1.2 yl into the gas chromatograph. A 3.8 % SE-30 on Diatoport S column and a temperature of 145°C was used for the analysis. The physostigmine THS and the salicylic acid TMS derivatives were eluted separately. Routine analysis over several days gave a precision of 11.5 %. 

Recently, EWOD actuation chips were developed into a multiplexed device that was used to simultaneously cleanup four samples. A sequence of seven actuation steps were performed for each sample (1) generation of sample droplets (0.02 p.L), (2) transport and drying of sample droplets, (3) generation of rinsing droplets, (4) transport of rinsing droplets to the sample sites for selective dissolution of urea, (5) transport and disposal of the rinsing droplets, (6) generation of MALDI matrix solution droplets, and (7) delivery of matrix droplets to the dried peptide spots. 

The influence of temperature on the formation of the PAPS porous structure has been considered, by way of example, for two samples synthesized in the presence of ethanol and DMF. It is known that any increase in the temperature of the silica gel precipitation leads to an increase in the sorptive capacity and effective diameter of pores, that is promotes formation of adsorbents with a large-porous structure [26]. This effect is usually related to variations in the mobility of particles and, as a consequence, in their aggregative stability. A similar pattern of increasing in values of Vs and Jeff is also observed for samples 14 and 19 in comparison to samples 75 and 20 prepared at a low temperature and at room temperature respectively (see Table 33.1). This effect is especially pronounced in the situation when the non-water solvent is DMF. However, in this case, with increasing temperature, in the S p value there is not a decrease but an increase from 146 to 222 m /g. Here, of some importance seems to be the nature of DMF as a solvent that readily forms strong hydrogen bonds. This results in that some portion of DMF molecules is not removed upon vacuum drying of samples 19 and 20. In other words, samples 19 and 20 somewhat differ in their composition firom other samples of PAPS characterized in Table 33.1, and, therefore, the comparative study of their structural and adsorptive properties would not be correct. 

H. P. Schwarz, R. C. Childs, L. Dreisbach, S. V. Mastrangelo, and A. Kleschik, Potassium Rromide Disk Technique for Infrared Microanalysis with Freeze Drying of Samples Soluble in Organic Solvents but Insoluble in Water, AppL Spectroscopy 12, 35-38,1958. 

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