Thermal desorption with NaCl

In addition, SPME was applied to control triazole residues in wine (Zambonin et al., 2002). Analysis of triadimefon, propiconazole, myclobutanil, and penconazole was performed by a polyacrylate (PA) 85-pm silica fiber. A 2.5-mL wine sample is diluted 1 1 with H20 and trasferred in a 7-mL vial. After addition with 0.5g NaCl extraction is performed by immersing the fiber into the sample with stirring for 45 min. Thermal desorption of analytes into the GC injection port is performed at 250 °C for 5 min. 

FIGURE 12.30 The effect of pH on the desorption of preadsorbed nucleic acid molecules onto cationic thermally sensitive magnetic latex particles. Adsorption was performed using 10 mW phosphate buffer, pH 5.2, 10 M NaCl at 20°C, with an incubation time of 180 min. (From Elaissari, A. et al., J. Magn. Magn. Mater., 2001. With permission.)... 

A series of covalently supported ILs with magnetite core and silica gel shell were prepared for the immobilization of C. rugosa lipase [123]. The immobihzation of lipase was realized by adsorbing the lipase onto the support in a buffer solution. The immobilization promoted the thermal resistance of Hpase dramatically. The native lipase lost 70% activity after being treated at 60 °C. After immobihzation, its activity was maintained at >90%. The supported Hpase also had better reusabihty in the esterification reaction of oleic acid and butanol. The supported hpase retained 92% of its initial activity for the second ran, while its native counterpart retained only 35%. This makes the use of expensive enzymes more practical. Moreover, desorption experiments showed that the supported Hpase could endure 200 mM NaCl, Figure 2.39, while the commercial carboxymethyl cellulose-supported hpase lost about 90% of the enzyme when the NaCl concentration was 150 mM. 

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