Abstract
The thesis contained two parts. In the first part, automatic in-situ monitoring systems of volatile organic compounds (VOCs) in the ambient and wastewater were developed.The study describes continual monitoring of the volatile organic air pollutants, acetone and toluene, in HsinChu Science Park (HSP) during an inclement weather occurrence, i.e., typhoon. A total of 53 polar and nonpolar compounds were identified and analyzed. The method detection limit (MDL) was 0.4 ppbv on average. The study presents a novel system, which continuously monitors polar VOCs in industrial wastewater. The system utilizes an ultrasound coupled autosampler, headspace solid-phase microextraction (HS-SPME), and a gas chromatography/flame ionization detection GC/FID for onsite, real-time detection and quantification of VOCs. The MDL was between 3.19ppb and 7.57ppb. In another part, the study using pressurized liquid carbon dioxide to extract cantharidin from Mylabris was investigated. The result achieves green extraction of bioactive ingredients in the insect, and the extraction efficiency of 95% (three times) was obtained at pressure of 1 MPa, temperature of 60°C, static extraction time of 30 minutes and with 4 ml of acetonitrile as modifier. In addition to the identification of the extract, i.e., cantharidin, by chromatographic approach, an in vitro assay for the effect of the extract on the cell was performed, the result reveals that the cantharidin-extracted is efficacious for primary medicinal available. The study proposes to verify the hypoglycemic effect of the flavonoids extracted from guava leaves on type 2 diabetic mice. When comparing the total flavonoid contents from various extraction methods, pressurized-methanol extraction had the highest levels (38.4±1.5 mg g-1). The major flavonoids of guava leaves were analyzed with mass spectrometry (MS) coupled with a high-performance liquid chromatograph, diode-array detector (HPLC-DAD). To confirm the hypoglycemic effect, an animal fasting test was conducted. In summary, both primary extracts (dose of 0.5 g Kg-1) and isolated flavonoids (dose of 40 mg Kg-1) from guava leaves had hypoglycemic effects (P<0.001). However, the quercetin flavonoid in guava leaves was only one of the active compounds with hypoglycemic activity, not the most major active compound.