2 resultados para Society for the Promotion of Temperance in Haverhill and Vicinity, Mass.
em Digital Commons at Florida International University
Resumo:
Background Sucralose has gained popularity as a low calorie artificial sweetener worldwide. Due to its high stability and persistence, sucralose has shown widespread occurrence in environmental waters, at concentrations that could reach up to several μg/L. Previous studies have used time consuming sample preparation methods (offline solid phase extraction/derivatization) or methods with rather high detection limits (direct injection) for sucralose analysis. This study described a faster and sensitive analytical method for the determination of sucralose in environmental samples. Results An online SPE-LC–MS/MS method was developed, being capable to quantify sucralose in 12 minutes using only 10 mL of sample, with method detection limits (MDLs) of 4.5 ng/L, 8.5 ng/L and 45 ng/L for deionized water, drinking and reclaimed waters (1:10 diluted with deionized water), respectively. Sucralose was detected in 82% of the reclaimed water samples at concentrations reaching up to 18 μg/L. The monthly average for a period of one year was 9.1 ± 2.9 μg/L. The calculated mass loads per capita of sucralose discharged through WWTP effluents based on the concentrations detected in wastewaters in the U. S. is 5.0 mg/day/person. As expected, the concentrations observed in drinking water were much lower but still relevant reaching as high as 465 ng/L. In order to evaluate the stability of sucralose, photodegradation experiments were performed in natural waters. Significant photodegradation of sucralose was observed only in freshwater at 254 nm. Minimal degradation (<20%) was observed for all matrices under more natural conditions (350 nm or solar simulator). The only photolysis product of sucralose identified by high resolution mass spectrometry was a de-chlorinated molecule at m/z 362.0535, with molecular formula C12H20Cl2O8. Conclusions Online SPE LC-APCI/MS/MS developed in the study was applied to more than 100 environmental samples. Sucralose was frequently detected (>80%) indicating that the conventional treatment process employed in the sewage treatment plants is not efficient for its removal. Detection of sucralose in drinking waters suggests potential contamination of surface and ground waters sources with anthropogenic wastewater streams. Its high resistance to photodegradation, minimal sorption and high solubility indicate that sucralose could be a good tracer of anthropogenic wastewater intrusion into the environment.
Resumo:
The use of technology in schools is no longer the topic of educational debates, but how to ensure that technology is used effectively continues to be the focal point of discussions. The role of the principal in facilitating the successful integration of technology in the school is well established. To that end, the Florida Department of Education implemented the FloridaLeaders.net: a three-year professional development project in technology for school administrators. The purpose of this study was to investigate the effectiveness of this professional development project on integrating technology in elementary schools. ^ The study compared a group of schools whose principals have participated in the FloridaLeaders.net (FLN) program with schools whose principals have not participated in the program. The National Technology Standards for School Administrators and the National Technology Standards for Teachers were used as the framework to assess technology integration. ^ The sample consisted of three groups of educators: principals (n = 47), media specialists (n = 110), and teachers (n = 167). Three areas of technology utilization were investigated: (a) the use of technology in management and operations, (b) the use of technology in teaching and learning, and (c) the use of technology for assessment and evaluation. Analyses of variances were used to examine the differences in the perceptions and use of technology in each of the three areas, among the three groups of educators. ^ The findings indicated that the difference between FLN and non-FLN schools was not statistically significant in most of the technology indicators. The difference was however significant in two cases: (a) The use of technology for assessment and evaluation, and (b) The level of technology infrastructure in FLN schools. Additionally, all FLN and non-FLN groups reported the need for technology training for teachers to provide them with the necessary "know-how" to effectively integrate technology into the classrooms. ^ These findings would indicate that FloridaLeaders.net was not effective in integrating technology in schools over and above other current efforts. It is therefore concluded that the FLN project had some favorable impact but had not met all of its stated objectives. ^