ABSTRACT
The coupling of flow field flow fractionation (FlFFF) with ICP-MS/MS for the fractionation and analysis of natural nanoparticles (NPs) in environmental samples is becoming more popular. However, the applicability of this technique to nonaqueous samples, such as gas condensates from petroleum hydrocarbon samples, has not been reported yet. In this study, an asymmetric flow-field flow fractionation (AF4) system coupled with UV and MALS detectors has been optimized to perform the fractionation of natural NPs present in a gas condensate sample, using THF as the carrier liquid. Prior to this, STEM images indicated the presence of both large (200 nm and more) and smaller (50 nm and less) particles, whose irregular shape is probably due to agglomeration. AF4-UV-MALS-ICP-MS/MS confirmed the presence of various NPs and colloids, some containing aromatic compounds as well as various metals, including Hg. The recovery against an injection without crossflow is around 75% for most metals. The presence of Hg-containing NPs was confirmed with offline single particle ICP-MS (spICP-MS), using THF as a solvent. These NPs were identified as HgS using STEM-EDX. These results highlight, for the first time, that particulate matter may contaminate gas condensates with a series of elements (Al, P, S, Ti, V, Mn, Fe, Co, Cu, Zn, As, Se, Cd, Hg, and Pb), which can make the upstream use problematic, especially for mercury.
ABSTRACT
OBJECTIVE: The purpose of this study was to assess the effects of a clinical decision support (CDS) tool aimed at decreasing the prescribing of glyburide, a potentially inappropriate medication (PIM), in patients 65 years of age and older. DESIGN: Quasi-experimental, pre-post intervention study. SETTING: Ambulatory care clinics of an academic medical center. INTERVENTION: The tool appeared to providers when entering new prescriptions or refills for glyburide. Glimepiride, which is a more appropriate sulfonylurea, was suggested as an alternative at order entry. MAIN OUTCOME MEASURE(S): The primary outcome was the prescribing of glyburide orders, measured as a percentage of the total oral diabetic medications ordered in patients 65 years of age and older, during the study period. The secondary outcome measured was the response to the CDS tool (accept versus reject). RESULTS: The CDS tool alerted providers 101 times during the 90-day postimplementation period. When the tool appeared, patients were transitioned off of glyburide 17.8% of the time. Subanalysis found that when physicians viewed the alert, patients were transitioned off of glyburide 46.2% of the time. As a percentage of the total number of oral diabetic medications, glyburide prescribing was significantly decreased from pre- to postimplementation study period (3.3% vs. 1.2%; P < 0.001). CONCLUSIONS: A CDS tool can be used in the ambulatory care setting to influence prescribing and provide a safer alternative medication. Additional information is needed to test the use of a CDS tool in conjunction with education to ensure providers are comfortable with and understand implications of a CDS tool.
