No abstract

Cloud point extraction was successfully applied to the preconcentration of phenothiazine derivatives, such as pericyazine (PC), chlorpromazine (CP) and fluphenazine (FUL), for gas chromatography (GC). Phenothiazine derivatives were separated from surfactants by passing the surfactant-rich phase through a cation exchange column after cloud point extraction, permitting the determination of the phenothiazine derivatives extracted in the surfactant-rich phase by GC. The optimal condition for the cloud point extraction of phenothiazine derivatives was also investigated using Triton X-100, Triton X-114, and PONPE10. Triton X-114 provided the most efficient recovery of phenothiazine derivatives among the surfactants used. The addition of sodium chloride and excess ammonia to the sample solution resulted in a decrement of the recovery of the phenothiazine derivatives. The proposed method was applied to the determination of phenothiazine derivatives in spiked human serum by GC. The recoveries of PC, CP, and FUL in spiked human serum were 95.1%, 87.1%, and 84.7%, respectively.

Phosphorus-containing amino acid-type herbicides (PAAHs) and their metabolites in human plasma and whole blood were extracted with titania and determined by capillary electrophoresis (CE). The recoveries of glyphosate (GLYP), aminomethylphosphonic acid (AMPA), gluphosinate (GLUF), and 3-methylphosphonico-propionic acid (MPPA) from human plasma were 84.6, 76.8, 90.4, and 89.6%, respectively. The recoveries of GLYP, AMPA, GLUF, and MPPA from whole blood were 79.6, 84.4, 36.9, and 31.8%, respectively. The low recoveries of GLUF and MPPA from whole blood were improved by the dilution of whole blood with water to 4-fold.

The effects of residual solvent on the glass transition temperature (T g) of poly(methyl methacrylate) (PMMA) were studied. A small amount of solvent in a film obtained by solution casting was found to remain even after vacuum evaporation for 30 h and compression-molding at 200 °C. The amount of residual solvent was less than 0.5 %, as revealed by gas chromatography. Therefore, this phenomenon is different from the plasticizing effect. A shift of the T g to a lower temperature was attributed to strong ion-dipole interactions between the solvent molecules and the carbonyl group in PMMA molecules. Such interactions suppressed the associated states of PMMA, which greatly affected chain mobility.

Photochromic compounds have attracted much attention because of their potential application in photonic devices such as optical memories and optical switches. Diaryl ethenes (DE) are known to show excellent thermal stability and resistance to fatigue, [1] and they are one of the most promising family of compounds for such applications. The two isomers, open-ring and closed-ring, undergo reversible cyclization/