Extraction Cont

Table 8.2 Selected Applications of Liquid—Liquid Extraction—cont d... 

The recoveries of clomeprop and its metabolite DMPA in soil after extraction with acetonitrile-water (4 1, v/v) by HPLC/UV (234 nm) are >90% The recoveries of propanil and its metabolite, 3,4-dichloroaniline, in soil are 95 and 76%, respectively, by Soxhlet extraction and LC/PAD determination. Diflufenican is added to soil in the range 0.002-0.008 mg kg to validate the method developed by Conte et al. The average recovery from the soil by this method is 92 5%. 

M.A. Lage Yusti and J.L. Cortizo Davina, Supercritical fluid extraction and high-performance hquid chromatography-fluorescence detection method for polycyclic aromatic hydrocarbons investigation in vegetable oil. Food Cont. 16 (2005) 59-64. 

Example 13 The extraction of Zn(II) by (l-diketones and phosphoryl adduct formers (cont. of Example 5). 

Example 14 The extraction of Cu(II) by HTTA (cont. from Example 4). 

Example 15 Extraction of Th(IV) by acetylacetone (cont. from Example 12). 

Having accomplished the homogenization of the sample, extraction of free amino acids is usually a simple process of stirring the sample in an appropriate solvent. This is typically a dilute solution (0. IN) of hydrochloric acid (2,7). Elevated temperatures may be used to assist dissolution, but care must be taken not to damage the more acid-labile amino acids. More recently, Moret and Conte (8) report that 0.1N HC1 was not a suitable solvent for all types of food samples. For some types of meat samples, 5% trichloroacetic acid is reported to afford superior performance (for biogenic amines, also amino acids ). It is not unusual to see perchloric acid employed for extraction from meat tissues (also more commonly for biogenic amines). 

Chu, Y. J., Werth, C. J., Valocchi, A. J.,Yoon, H., and Webb, A. G. (2004). Magnetic resonance imaging of nonaqueous phase hquid during soil vapor extraction in heterogeneous porous media. J. Cont. Hydrol. 73,15-37. 

We also need to understand how social insects are capable of extracting different kinds of information from the cuticular profile (Peeters and Liebig, 2009). Besides information about fertility, many other types of information are encoded. The interference in nestmate recognition based on cuticular hydrocarbons with information about fertility is particularly interesting. Different thresholds for recognition of different information may be involved (Le Conte and Hefetz, 2008). Further challenges to the understanding of profile discrimination are obvious when we consider task-specific cues (see Chapter 12). 

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