We did an extraction on a solution consisting of a 120 mg sample of fluorene contaminated w/ fluorenone dissolved in 12 mL of ethyl acetate, we washed (extracted) it with 6 mL of water twice. a. Why did we extract (washed) it with water twice? b. What compounds would make up the first aqueous layer (after the first wash), and then the second aqueous layer (after the second wash), as well as the final remaining organic layer?
Answers
Answer:
Determination of chlormequat in pears by liquid chromatography/mass spectrometry
NARCIS (Netherlands)
Mol, H.G.J.; Dam, R.C.J. van; Vreeken, R.J.; Steijger, O.M.
2000-01-01
A straightforward and reliable method was developed for the determination of chlormequat in pears by liquid chromatography/mass spectrometry (LC/MS). Water and methanol were compared as extraction solvents. Because no significant differences in extraction efficiency or repeatability were found,
Determination of organophosphorus acids by thermo-spray liquid chromatography-mass spectrometry
NARCIS (Netherlands)
Wils, E.R.J.; Hulst, A.G.
1988-01-01
The determination of thirteen organophosphorus acids, hydrolysis products of nerve agents and pesticides, by a combination of ion-pair liquid chromatography on a reversed-phase C18 column and thermospray mass spectrometry was investigated. Ammonium acetate and three tetraalkylammonium salts with
Recent applications of gas chromatography with high-resolution mass spectrometry.
Science.gov (United States)
Špánik, Ivan; Machyňáková, Andrea
2018-01-01
Gas chromatography coupled to high-resolution mass spectrometry is a powerful analytical method that combines excellent separation power of gas chromatography with improved identification based on an accurate mass measurement. These features designate gas chromatography with high-resolution mass spectrometry as the first choice for identification and structure elucidation of unknown volatile and semi-volatile organic compounds. Gas chromatography with high-resolution mass spectrometry quantitative analyses was previously focused on the determination of dioxins and related compounds using magnetic sector type analyzers, a standing requirement of many international standards. The introduction of a quadrupole high-resolution time-of-flight mass analyzer broadened interest in this method and novel applications were developed, especially for multi-target screening purposes. This review is focused on the development and the most interesting applications of gas chromatography coupled to high-resolution mass spectrometry towards analysis of environmental matrices, biological fluids, and food safety since 2010. The main attention is paid to various approaches and applications of gas chromatography coupled to high-resolution mass spectrometry for non-target screening to identify contaminants and to characterize the chemical composition of environmental, food, and biological samples. The most interesting quantitative applications, where a significant contribution of gas chromatography with high-resolution mass spectrometry over the currently used methods is expected, will be discussed as well. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Determination of ribavirin in human serum using liquid chromatography tandem mass spectrometry
NARCIS (Netherlands)
van der Lijke, H.; Alffenaar, J.-W. C.; Kok, W.Th.; Greijdanus, B.; Uges, D.R.A.
2012-01-01
A method has been developed for the determination of ribavirin in human serum for therapeutic drug monitoring purposes, using liquid chromatography electrospray ionization mass spectrometry. Separation was obtained with a mobile phase gradient starting and ending in 100% aqueous conditions using a
Determination of trimethyllead reference material using high performance liquid chromatography-inductively coupled plasma mass spectrometry
International Nuclear Information System (INIS)