A solid-phase extraction (SPE)-gas chromatography (GC)-mass spectrometry (MS) analytical method was developed for the simultaneous analysis of natural free estrogens and their conjugates in wastewater samples. Natural free estrogens and their conjugates in wastewater were successfully separated by the oasis hydrophilic-lipophilic balance solid phase extraction (Oasis HLB SPE) method, and the conjugates were initially enzyme hydrolyzed by b-glucuronidase or arylsulfatase from Helix pomatia prior to derivatization. N-methyl-N-(tert-butyldimethylsilyl)trifluoroacetamide (MTBSTFA) plus 1% tert-butyldimetheylchlorosilane (TBDMCS) was chosen as the derivatization reagent, and the most appropriate conditions of derivatization were determined to be at 958C for 90 min. The recovery ratios of nine target chemicals were determined by spiking them in 1 L of ultra-purified water or the influent of a wastewater treatment plant (WWTP). The recovery ratios of six out of nine for the analytes ranged from 73.3 -114.9% with relative standard deviations (RSD) from 1.6 -19.9%. The established method was successfully applied to environmental wastewater samples which were collected from one municipal wastewater treatment plant (WWTP) in Osaka, Japan, for the determination of natural free estrogens and their conjugates. In the influent sample, E1, E2, E1-3S, E3-3S, and E1-3G were detected at concentrations of 16.6, 9.6, 8.2, 21.9, and 3.2 ng L -1 , respectively. However, only E1 was detected at a high concentration of 44 ng L -1 in the effluent sample, suggesting that it is the dominant natural free estrogen in the effluent.

Abstract— 8‐in. AC plasma display panels with front address (FA) structures were developed. Deep barrier ribs, high‐Xe‐content gas, and long sustain gaps were applied to FA structures to achieve high luminous efficacy. The FA structures have several advantages over conventional structures. Because address electrodes are closer to sustain electrodes, FA PDPs can be driven at lower address voltages, under the condition of deep barrier ribs or high‐Xe‐content gas, than conventional PDPs. A disadvantage of FA PDPs is relatively high capacitance between the sustain electrodes and address electrodes compared to that of conventional PDPs.

8-inch High Definition (corresponding to 50" Full HD (1080p)) AC Plasma Display Panels with front address structures are developed. These structures show high luminous efficacy without increasing address voltages even if the cells are high definition.