Dietary cyclopropenoid fatty acids (CPFA) have long been known to cause pronounced physiological disorders in both farm and laboratory animals. Past work has shown CPFA to be a powerful promoter of carcinogenesis in trout, rats and mice. Sterculic and malvalic acids (CPFA's) are found in seed lipids of plants from the order Malvales. Two members of this order are cotton and kapok, both of which are used extensively as cooking oils for human consumption. Present chemical and instrumental methods of analysis for CPFA are effective only at CPFA levels above 0.1%, and accurate only at levels above 1%. A more sensitive method of analysis was developed exploiting recent technological advances in glass capillary gas chromatography (GCGC). By the use of cold on-column injection, and positioning of the column at the base of the detector flame, this method eliminates two problem areas found in other GC methods. The other common component involved in CPFA decomposition, during GC analysis, is the column. Vitrious silica columns with an inert stationary phase, SE-30, were shown to separate the highly reactive CPFA without decomposition. Proof of stability during analysis was obtained by changing the variables of relative time on column and column temperature. This method not only allows individual determination of sterculic and malvalic acid concentrations, it is rapid, accurate (to the 70 parts per million range), and is superior to other instrumental and chemical methods. The CPFA concentration for okra, hollyhock, cheese weed, seashore mallow, kapok, and white cap cottonseed oil are as follows: 0.3% to 0.92%, 0.33%, 2.6%, 2.6%, 12.8%, and 75ppm, respectively. The two different values for okra were found because seeds from two different growing seasons were analyzed. No CPFA could be detected in Diet Imperial Margarine, raw cocoa beans, cocoa butter or Lucca's winterized cottonseed oil. / Graduation date: 1987

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Thesis (Ph.D.)--Boston University / PLEASE NOTE: Boston University Libraries did not receive an Authorization To Manage form for this thesis or dissertation. It is therefore not openly accessible, though it may be available by request. If you are the author or principal advisor of this work and would like to request open access for it, please contact us at open-help@bu.edu. Thank you. / The recent discovery of a number of metabolites of estrogens has necessitated the development of new methods for their analysis. The available methods of proven merit fall short of determining these newer fractions. Moreover, these methods are too time consuming to determine the daily excretion of estrogenic steroids. The development of a relatively rapid and highly sensitive methodfor the estimation of several estrogens was, therefore, undertaken. The procedure involves hydrolysis, extraction, preliminary purification and separation, acetylation and gas chromatography of the steroids. Simultaneous separation and quantification by gas-liquid chromatography (GLC) not only allows a more rapid analysis but sensitivity is also increased by the use of ionization detectors. Determination of the optimal flow rate of hydrogen, air and carrier gas was found necessary for obtaining maximum detection response. Detector linearity for seven estrogens over an adequate range was established. Since free estrogens suffer severe adsorption on the gas chromatographic column and generally do not separate well, the steroids were analyzed as suitable derivatives. After examining several such derivatives (acetates, formate, trifluoroacetate, trimethylsilyl ethers) the acetates were found to be most suitable for the specific purpose. Optimal conditions for the acetylation of steroids in submicrogram quantities were established. The effect of the solid support, stationary phase, priming of the column with estrogens and solvent impurity in quantitative analysis by gas chromatography was also investigated. Preliminary separation of estrogens into separate groups was necessary because of poor resolution and long retention times resulting in poor detector response. Moreover, in a crude urine extract, the large number of contaminants obscuring the peaks of the lesser estrogen components, mandated preliminary purification. Thin-layer chromatography crtc) was found to be a versatile tool for this purpose. Among several solvent systems developed, three were found to be eminently suitable. TLC in System I (benzene:ethyl acetate 1:1) separates the estrogens into four fractions: (a) estrone and 2-methoxyestrone, (b) ring-D-alpha-ketols and estradiol, (c) 16-epiestriol, and (d) estriol. Further TLC of fraction (b) in System II (pet. ether:dichloromethane:ethanol 10:9:1) was found necessary to separate these estrogens from the neutral 17-ketosteroid. An alternate method of preliminary purification and separation for the measurement of the three classical estrogens in low titer urine, involving alumina chromatography, has been developed. Following these preliminary procedures GLC permitted rapid separation and highly sensitive quantification of the individual fractions [TRUNCATED] / 2031-01-01

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Thesis (Master)--İzmir Institute of Technology, İzmir, 2004. / Includes bibliographical references (leaves. 82-84).

Thesis (Ph. D.)--University of Washington, 1998. / Vita. Includes bibliographical references (leaves [129]-140).