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201.
A study undertaken following recent reports of deaths in neonatal children associated with the use of benzyl alcohol resulted in the development of a stability-indicating high-performance liquid chromatographic assay of benzyl alcohol in plasma using benzocaine as internal standard. Thawed plasma samples were diluted and subjected to solid-phase extraction using Extrelut and eluted with ethyl acetate. The evaporated eluate was reconstituted with mobile phase and chromatographed on a C18 column with water-acetonitrile-glacial acetic acid as mobile phase and detection at 254 nm. Baseline separation was achieved within 12 min for benzyl alcohol, benzaldehyde, benzoic acid, hippuric acid and benzocaine. Peak-height ratios were linear over 80-640 ng of benzyl alcohol injected (r = 0.998) and over 10-80 ng of benzoic acid injected (r = 0.999). Benzaldehyde and hippuric acid were not quantitated because these compounds were not detectable in actual dog plasma. Validation studies by spiking dog plasma with benzyl alcohol and benzoic acid gave overall percent recoveries (+/- relative standard deviation, n = 4) of 98.3 +/- 3.0 and 101.4 +/- 7.6%, respectively. The method was applied to the assay of actual plasma samples. Since benzyl alcohol is very susceptible to oxidation to benzaldehyde and benzoic acid, its purity in bulk liquid samples can be determined by this method. 相似文献
202.
A. R. Manning Paul J. A. Soye Patrick A. McArdle Desmond Cunningham 《Transition Metal Chemistry》1995,20(6):540-547
Summary [Fe2(-Cp)2(CNAr)4] (2) (540-01, C6H4Me-2, C6H4Et-2, C6H3Me2-2,4, C6H3Me2-2,6, C6H3(Me)Et-2,6, C6H3Et2-2,6 or C6H3
i-Pr2-2,6) react with I2 to give [Fe(-Cp)(CNAr)2I], but with Br2[Fe(-Cp) (CNAr)3]+ salts are the only products; IBr gives a mixture of the two. With SnX2 (X = F, Cl, Br or I) in refluxing n-butanol, (2) gives isolable [{Fe(-Cp)(CNAr)2}2SnX2] only when the CNAr ligands have two ortho substituents, otherwise decomposition occurred. When X = F, [Fe(-Cp) (CNAr)2SnF3] was also obtained from this reaction. Attempts to prepare [Fe(-Cp)(CNAr)2X] (X = Cl or Br) by reaction of (2) with HX in the presence of air gave rather unstable products which with SnX2 formed [Fe(-C5H5)-(CNAr)2SnX3]. Similar compounds, [Fe(-Cp) (CNAr)2 SnX2I], were obtained from [Fe(-Cp)-(CNAr)2I] and SnX2 (X = Cl or Br but not I). All of these complexes are much less stable than their Fe(-Cp)(CO)2 counterparts; all decompose in solution to [Fe(-Cp)(CNAr)3]+ which then break down to unidentified species. X-ray diffraction studies show that in [Fe(-Cp)(CNC6H3-i-Pr2-2,6)2I] and [{Fe(-Cp)(CNC6H3Me2-2,6)2}2SnBr2] there is pseudo-octahedral coordination about Fe. In the latter there is also distorted tetrahedral coordination about Sn so that its structure is very similar to that of [{Fe(-Cp)(CO)2}2SnCl2]. Spectroscopic studies show that in all complexes rotation of the aryl rings of the CNAr ligands cannot be slowed in solution, and that there is free rotation about all 540-02 bonds. 相似文献
203.
Manning DA 《Rapid communications in mass spectrometry : RCM》2008,22(11):1640-1642
Helium occurs naturally in association with geological fluids and is regarded by economists as a mineral commodity. Commercially, helium is obtained as a by-product from natural gas reservoirs that typically have concentrations of up to 1% He by volume (STP). Existing sources of helium within the USA are expected to decline in parallel with declining natural gas production. Huge reserves of helium occur in Algeria, Qatar and Russia, which are likely to dominate production for the next several decades. In this context, political and economic factors that affect hydrocarbon gas production may influence the availability and price of helium. 相似文献
204.
The points homoclinic to 0 under a hyperbolic toral automorphism form the intersection of the stable and unstable manifolds
of 0. This is a subgroup isomorphic to the fundamental group of the torus. Suppose that two hyperbolic toral automorphisms
commute so that they determine a ℤ2-action, which we assume is irreducible. We show, by an algebraic investigation of their eigenspaces, that they either have
exactly the same homoclinic points or have no homoclinic point in common except 0 itself. We prove the corresponding result
for a compact connected abelian group, and compare the two proofs.
The second author would like to thank the Austrian Academy of Sciences and the Royal Society for partial support while this
work was done. 相似文献
205.
Jill B. Williamson Sally E. Lewis Robert R. Johnson Irene M. Manning Frank A. Leibfarth 《Angewandte Chemie (International ed. in English)》2019,58(26):8654-8668
Synthetic manipulation of polymer substrates is one of the oldest and most reliable methods to increase the functional diversity of soft materials. Modifying the chemical structure of polymers that are already produced on a commodity scale leverages the current high‐volume and low‐cost production of commodity plastics for the discovery of modern materials. A myriad of polymer C?H functionalization methods have been developed which enable the modification of material properties on both a laboratory and industrial scale. More recently, driven by advances in C?H activation, photoredox catalysis, and radical chemistry, chemoselective approaches have emerged as a means to impart precise functionality onto commodity polymer substrates. This Review discusses the historical significance of and contemporary advances in the C?H functionalization of commodity polymers. The conceptual approach outlined herein presents exciting new directions for the field, including increasing the value of otherwise pervasive materials, uncovering entirely new material properties, and a viable path to upcycle post‐consumer plastic waste. 相似文献
206.
Ohne Zusammenfassung 相似文献
207.
B. Brukner W. Overbeck J. Duclaux J. Errera H. Bechhold L. Gutlohn H. W. Morse G. W. Pierce V. Szidon E. Fouard und J. Manning 《Fresenius' Journal of Analytical Chemistry》1927,71(10):394-398
Ohne Zusammenfassung 相似文献
208.
209.
Siddharth V. Patwardhan Joseph R.H. Manning Mauro Chiacchia 《Current Opinion in Green and Sustainable Chemistry》2018
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210.