## LSU Historical Dissertations and Theses

1994

Dissertation

#### Degree Name

Doctor of Philosophy (PhD)

#### Department

Veterinary Physiology, Pharmacology, and Toxicology (Veterinary Medical Sciences)

Steven A. Barker

#### Abstract

The present investigations were conducted to examine the use of a new methodology termed matrix solid phase dispersion (MSPD) in combination with chromatographic techniques to analyze different classes of environmentally significant compounds in biological matrices. The research described in this dissertation represents the author's work to demonstrate the feasibility of improving environmental analytical methods by employing MSPD and chromatographic techniques in combination or separately. Preliminary tests were conducted to determine some of the parameters that would be used to test MSPD extraction techniques and to chromatograph standards and extracts of benzo (a) pyrene (BAP), benzo (a) pyrene ring-oxidized metabolites, Aroclor 1254 (PCB) and nine chlorinated pesticides. In each study, catfish (Ictalurus punctatus) muscle tissue (0.5g for each analysis) was fortified with either BAP, PCBs (Aroclor 1254) or nine chlorinated pesticides and subsequently mixed with 2.0 grams of octadecylsilyl derivatized silica (C$\sb{18}$) using a mortar and pestle. The resultant C$\sb{18}$-tissue blend was quantitatively transferred to a plastic 10 ml syringe and configured as a column. The target compounds were eluted from each column with a total of 8.0 ml of acetonitrile. These extracts were then subjected to a reverse-phase high pressure liquid chromatograph equipped with programmable ultraviolet-visible and fluorometric detectors for BAP analyses or a packed or capillary column gas chromatograph equipped with an electron capture detector for chlorinated pesticide or PCB analyses. In each study, catfish muscle tissue was fortified at six different concentrations (including a blank control) with five replicates run for each concentration. The tissue fortification levels for the BAP and the PCB studies were 0.20, 0.50, 1.0, 2.0, and 4.0 $\mu$g/g tissue sample. The tissue fortification levels for the chlorinated pesticide study were 31.3, 62.5, 125, 250, and 500 ng/g. The results from these studies demonstrated acceptable average relative percent recoveries of 74 $\pm$ 11% to 112 $\pm$ 13% for BAP, 59 $\pm$ 3.3 to 77 $\pm$ 9.5% for PCBs, and 82 $\pm$ 4.8% to 97 $\pm$ 3.6% for nine chlorinated pesticides.

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