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A fast and efficient method has been demonstrated for the trace determination of six important metabolites of synthetic pyrethroids including cis- and trans-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane-1-carboxylic acid (cis- and trans-Cl2CA), cis-3-(2,2-dibromovinyl)-2,2-dimethylcyclopropane-1-carboxylic acid (cis-Br2CA), 4-fluoro-3-phenoxybenzoic acid (4-F-3-PBA), 3-phenoxybenzoic acid (3-PBA), and 2-phenoxybenzoic acid (2-PBA) in environmental water samples using hollow fiber (HF)-mediated liquid-phase microextraction (LPME) coupled with in-syringe derivatization (ISD) followed by gas chromatography (GC) with electron capture detector (ECD) analysis. This method utilizes a HF membrane segment impregnated with extraction solvent as the LPME sampling probe, which was connected to a microsyringe pre-filled with derivatizing agents, and it was immersed into sample solution for extraction. After extraction, the extracting solution was subjected to derivatization reaction that was performed inside the syringe barrel followed by GC-ECD analysis. Under optimal conditions, the best extraction efficiency was obtained using sampling probe (2.0 cm hollow fiber) impregnated with 1-octanol immersed into water sample (5.0 mL, adjusted pH below 1.0) and stirring (1,250 rpm) for 10 min at 70 °C and diisopropylcarbodiimide (2 μL) and 1,1,1,3,3,3-hexafluoro-2-propanol (1 μL) were the derivatizing agents used. The detection limits of 3 ng mL−1 for cis- and trans-Cl2CA, 2 ng mL−1 for cis-Br2CA, 6 ng mL−1 for 4-F-3-PBA, and 0.6 ng mL−1 for 3-PBA and 2-PBA. The method showed good linearity (R 2 = 0.973−0.998), repeatability from 4.0 to 13 % (n = 5), recovery from 79.2 to 95.7 %, and enrichment factors ranged between 109 and 159 for target analytes spiked in water samples. The proposed method and conventional methods were compared. Results suggested that the proposed HF-LPME-ISD/GC-ECD method was a rapid, simple, inexpensive, and eco-friendly technique for the analysis of metabolites of pyrethroids.

In Taiwan, augmentation rhinoplasty and double-eyelid blepharoplasty are the most popular aesthetic procedures. Although aesthetic concepts vary for different races, the current concept of nasal and facial beauty shows a tendency to correspond to that for white people. The authors present their 10-year experience with a simple and practical approach of simultaneous blepharoplasty and rhinoplasty. This study enrolled 255 consecutive patients who underwent simultaneous rhinoplasty and blepharoplasty between January of 1996 and December of 2005. All were Chinese in ethnic origin. The patients in the series were predominantly women. Only 10 were men. Five of the cases involved congenital palpebral anomalies including congenital entropion, congenital ptosis, and Down syndrome. A total of 245 patients had an adequate follow-up period longer than 5 years. The patients’ satisfaction and postoperative complications were recorded. Among the 245 patients receiving the balanced rhinoplasty, there were no cases of implant extrusion, displacement, or infection. Most of the patients (230/245 cases, 94%) were satisfied with their nasal and periocular shape. The authors believe that simultaneous blepharoplasty and rhinoplasty are a simple and reliable method for effecting better results for Asians.

The presence of epicanthal folds and lack of supratarsal folds are unique features in most Asian eyelids. Although many surgical procedures are available to eliminate epicanthal folds, scarring on the medial canthus is still an obstacle for surgeons to overcome. From January of 1989 to November of 1997, we used modified Y-V advancement procedures in 148 cases to correct epicanthal folds in Asian eyelids. Five of those cases involved congenital palpebral anomalies, including congenital entropion, congenital ptosis, and Down syndrome. There were few complications in our series. We believe that the modified Y-V advancement procedure causes minimum scarring on medial canthus in correcting Oriental epicanthal folds and congenital palpebral anomalies. This procedure can also be simultaneously combined with blepharoplasties and corrective procedures of eyelids.

Metabolites of synthetic pyrethroids such as cis-3-(2,2-dibromovinyl)-2,2-di-methylcyclo-propane-1-carboxylic acid, cis- and trans-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane-1-carboxylic acid), 3-phenoxybenzoic acid (3-PBA), and 4-fluoro-3-PBA are biomarkers for exposure to phenothrin, tetramethrin, cyfluthrin, cypermethrin, deltamethrin, and permethrin. In this study, the pyrethroid metabolites in workers' urine samples were monitored for the first time with a novel sample pretreatment process combining hollow fiber liquid phase microextraction (HF-LPME) and in-syringe derivatization (ISD) followed by gas chromatography-electron capture detector (GC-ECD) analysis. A micro-syringe pre-filled with derivatizing agents and syringe needle connected to an extracting solvent impregnated hollow fiber segment was used as the LPME probe. Pyrethroid metabolites were extracted and enriched simultaneously from urine samples by HF-LPME sampling and acid hydrolysis at 70 °C for 10 min. After sampling, the ISD was performed by mixing the extracting solution and derivatizing agents through plunger movements, followed by GC-ECD analysis. Parameters influencing the HF-LPME efficiency and ISD were investigated and optimized. Under optimum conditions, the method provided enrichment factors of 69.8-154.6, repeatability from 5.0 to 12% (n = 5), and good linearity (R(2) = 0.9980-0.9998) for interested analytes spiked in urine samples. The method detection limits ranged from 1.6 to 17 ng/mL. A comparison was performed between the proposed method and conventional methods. The proposed method was applied to analyze pyrethroid metabolites in the urine samples collected from workers of pesticide formulation plants. The results suggested that the proposed HF-LPME coupled ISD method was a rapid, simple, efficient, and eco-friendly technique in the biomonitoring of metabolites of pyrethroids in workers' urine.