The need for field and laboratory studies of the physical and
chemical behavior of environmentally significant organic molecules often
poses problems because of the toxicity of the chemical and the difficulty
of detecting it at environmentally significant concentrations.
Two dysprosium tracers, dysprosium (III) trisacetylacetonate trihydrate
and dysprosium(III) trisdibenzoylmethane monohydrate, were...
Two studies were conducted involving rare earth elements. In the
first study, the use of rare earth diethylenetriaminepentaacetic acid
(DTPA) complexes as stable actiable tracers, a method of stable-isotope
tracing with post-sampling neutron activation analysis, was explored.
The persistence of rare earth DTPA complexes in estuarine waters was
measured in...
Part 1
The concentration of seventeen elements in two species of fungus
which cause wheat bunt disease, Tilletia caries (DC.)Tul. (TS) and
Tilletia controversa Kiihn (DS), were determined by instrumental neutron
activation analysis in 37 TS spore samples, and 31 DS spore samples.
Aluminum was chosen as a soil contamination...
I. Lithium alkyl and aryl monosubstituted cyclooctatetraenide
dianions (Li₂ C₈H₇-R; R = methyl, n- butyl, sec- butyl, tert- butyl,
phenyl and benzyl) were synthesized by the reaction of the appropriate
organolithium reagent with cyclooctatetraene in diethyl ether or
tetrahydrofuran. The reaction occurred cleanly and with good yield
of lithium monosubstituted...
A method for the control of absolute stereochemistry in
morphine syntheses has been demonstrated by the resolution
and efficient racemization of the advanced morphine precursor , 9-methoxy-3-methyl-5,6-dihydro-3H-benzofuro[3,2-e]isoquinoline-
7(7aH)-one, I. This was accomplished by the facile coversion of optically resolved I to its ring opened
form, 5,6,7,8-tetrahydro-10-methoxy-3-methyl-7-oxo[1]benzoxonino[
6,7-c]pyridinium tosylate, II, (Equation...
A sensitive technique for the determination of As(III) and As{V)
at μ/L and sub-μg/L concentrations from a single sample aliquot
has been developed. This technique is based on the hydride
generation atomic absorption (HGAA) spectrophotometry. The hydrides
of the arsenic species are generated in a reaction vessel by mixing
the...
Studies of the use of NADH as the monitored fluorophore for enzymatic fluorescence kinetic methods are discussed. Interference studies
for the detection of NADH and the adaptation and optimization of fluorescence kinetic measurements to four serum assays are also described.
A microcomputer-controlled flow injection analysis (FIA) system was
designed and...
An automated on-line ion exchange trace enrichment system has
been developed to improve the detection limits of flame atomic
absorption (AA) spectrophotometry in the determination of trace
metals in natural waters. The sample solution is passed through a
column of Chelex-100 chelating resin by a carrier buffer stream
delivered from...
Improvements in instrumentation for fluorometric kinetic
measurements and the application of a new intensified diode array (IDA)
rapid scanning system to low level transient fluorescence measurements
are reported. This instrumentation is applied to a new fluorometric
kinetic method for thiamine (TM).
Modifications to the existing fluorometric reation rate instrument
include...
The concentration of chlorophyll in natural bodies of water is
commonly determined as a means to rapidly estimate the phytoplankton
biomass. The literature gives numerous warnings, however, as to the
problems involved with accurately determining chlorophyll
concentrations. The author's work at Crater Lake, Oregon enticed him
to explore critically the...