The organic matter in source rocks and oil shales distributed in the southeastern and southwestern parts of the Korean peninsular has been analyzed. A mixture of benzene, acetone and methanol was used to extract bitumen by Soxhlet extraction method. The extractable organic matter was separated into aliphatic hydrocarbons, aromatic hydrocarbons, and asphaltene by preparative thin layer chromatography. By urea adduction method, aliphatic hydrocarbons were separated into linear aliphatic hydrocarbons and cyclic or branched aliphatic hydrocarbons. The aliphatic hydrocarbons were analyzed by GC/FID and GC/MS. The gas chromatograms for linear aliphatic hydrocarbons showed the distribution of C₁₂-C₃₅ compounds. Generally, the odd number hydrocarbons were detected more than the even number hydrocarbons. From the total ion chromatograms and mass spectra of cyclic and branched aliphatic hydrocarbons, several compounds including 1-methylpropyl-cyclohexane were identified.

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An analytical method has been investigated for the efficient simultaneous determination of toxic volatile organic compounds (VOCs) in ambient air. The adsorption by the sorbent followed by thermal desorption was optimized for the various concerned parameters such as the selection of sorbent and the breakthrough volume to each compound as well as temperature, flow and time for the focusing trap, before the introduction of analytes to GC-MS. It was found that the multiple-bed packing of sorbents of Carbopack B and Carboxene 1000 allowed more than 60L of the breakthrough volume at 20°C and the recovery of 92-107% under the optimized conditions. The practical use of this method with the quantitation limit of 0.01-0.05 ppbv for 10L air sample was validated for the standard sample of VOCs. Finally, the method was applied to the real sample of air collected at the several locations of town and rural area over 24hours, and also at the fence line of chemical works.

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Heavy metals Cd, Zn, Cu, Pb, Cr and Ni in the paddy field which had contaminated by Cd and Pb, were re-examined. Soil samples were collected from panels of a hectare of paddy field in Luchu county of Tauyuan prefecture, Taiwan. Soil samples were taken from ten spots in each panel in regular 25m distance (length and width), and mixed through for analysis. Soils were sampled from surface down to 30cm depth. Heavy metals in the soil samples were extracted with 0.1M HCl and the extracts were analyzed by atomic absorption spectroscopy. Maximum amounts of metal are found: Cd 10.6ppm, Zn 84.0ppm, Cu 99.7ppm, Pb 58.1ppm, Cr 2.95ppm and Ni 16.6ppm.

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The focal study was made on the determination trace elements contained in human hair of workers in paint factory, including chromium, iron, lead, and manganese. The hair sample was pretreated with organic solvent and by microwave digestion before their trace metals were measured with Graphite Furnace System Atomic absorption spectrophotometers. The result showed that total Pb, Mn and Iron levels in hair of workers in paint factory were significantly different from those in normal control subjects (P<0.01), but the total. chromium level did not significant differ from that in normal control sub jects(P>0.05). The possible connection of these elements with the etiology of the worker is discussed.

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Iron complexes with dithiocarbamate derivatives are noted among the EPR spin-trapping reagents for NO in the biological systems because NO has a high affinity for the iron complexes. Among iron dithiocarbamates, iron complex with N-dithiocarboxy sarcosine and its NO complex are fairly soluble and stable in aqueous media. Therefore, these can be effectively utilized as an NO trapping reagent and a spin probe or an imaging reagent, respectively. Here, we show the current information of EPR detection and imaging of endogenously produced and exogenously supplied NO employing iron-dithiocarbamate complexes and their NO complexes.

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A 20-mer oligonucleotide whose 5′-end phosphate was modified with ω-thiohexyl group was applied in order to modify a Au electrode with its duplex form. Cyclic voltammograms of ferrocyanide/ferricyanide redox couple with the DNA-immobilized electrode gave the peak currents due to the reversible electrode reaction, which were significantly enhanced on adding acridine orange (AO). The cathodic peak current showed almost a linear relationship with AO concentration in the range of 10^-7-7×10^-7M, and then saturated beyond the concentration of 10^-6M. From the concentration-dependent profiles, an apparent binding constant of (9.1±5.4)×10⁵M^-1 was obtained for the AO-DNA system. The obtained data agreed fairly well with the reported value (1.2±0.3)×10⁶M^-1.

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The binding study and spectral behavior of novel DNA interacting dyes, bis(vinylpyridinium) benzene derivatives, are reported. Implantation of a extended π-electron moiety into a viologen molecule has lead to the preparation of a series of dicationic dyes with fluorescent properties and potential capability of interacting with DNA by both groove binding and intercalation mode. Drug-DNA interactions were investigated by UV-VIS absorption and fluorescence titration, and circular dichroism measurements. There were no clear isosbestic points in titration data which suggested complex interaction of drugs with DNA. As a tentative explanation of these results, we believe that dye molecules aggregate or intercalate with DNA at lower P/D ratios (DNA to dye concentration) and undergo redistribution in the minor groove at higher P/D ratios. The groove binding mode was supported by presence of induced CD spectra of dyes in the presence of AT sequence containing oligonucleotides. The most pronounced groove binding was observed for the curved m-bis(vinylpyridinium) benzene derivative. Such bimodal behavior may be of great importance for the further application of dyes since DNA sequence selectivity can also serve as valuable tool for the development of base selective DNA probing methods.

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(S)-(+)-2-(Anthracene-2, 3-dicarboximido)-1-propyl trifluoromethanesulfonate (AP-OTf) was synthesized as a chiral fluorescence derivatization reagent for carboxylic acids. Beraprost sodium (BPS), which is composed of four optical isomers, was derivatized with this reagent, and the derivatives were separated into each isomer by an HPLC using a silica gel column. This method was applied to determine BPS in human plasma. By the method, the determination range of the four isomers of BPS were 6-3000fmol (0.5-250ng/ml) and their detection limits were 3-4fmol (1.3- 1.7pg, signal-to-noise ratio=3). This method made it possible to detect 0.25-0.33ng/ml of each isomer of BPS in plasma.

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A simple and highly sensitive fluorimetric high-performance liquid chromatographic (HPLC) method was developed for the determination of amantadine in plasma. After a single-step extraction from plasma (50μl) with toluene, the drug and 1-(1-adamantyl)ethylamine (internal standard) were converted into the corresponding fluorescent derivatives by reaction with 3, 4-dihydro-6, 7-dimethoxy-4-methyl-3- oxo-quinoxaline-2-carbonyl chloride, a fluorescence derivatization reagent for amines, in the presence of triethylamine. The derivatives were separated within 20min on a reversed-phase column (YMC- Pack C₈) using isocratic elution with methanol-acetonitrile-water (35:35:30, v/v) and detected spectrofluorimetrically at 500nm with excitation at 400nm. The detection limit for amantadine added to plasma was 360fmol (54pg) ml^-1 plasma (18fmol on column) at a signal-to-noise ratio of three.

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A high performance liquid chromatographic determination of tranexamic acid and two vitamins, i.e., vitamin U chloride and anthranilic acid, with chemiluminescence detection was investigated. o-Phthalaldehyde(OPA) solution which contained 2-mercaptoethanol was used as a fluorescent labeling reagent. OPA solution was prepared by mixing OPA and 2-mercaptoethanol in ethanol, and then diluting with borate buffer solution. Bis(2, 4, 6-trichlorophenyl)oxalate and hydrogen peroxide were used a postcolumn chemiluminescent reagent. The intensity of the chemiluminescence was in the order of tranexamic acid> vitamin U chloride>anthranilic acid. The calibration curves for the compounds were linear at least in the range from 1x10^-7M to 1x10^-4M. The detection limits for tranexamic acid, vitamin U chloride and anthranilic acid were 5x10^-8M, 4x10^-7M and 7x10^-7M, respectively. The relative standard deviation was less than 9%(n=5). The proposed method was applied to the determination of tranexamic acid and vitamin U chloride in commercially available medicine.

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Study on the intermediary species of theophylline oxidation process is very important for understanding its pharmacological action. Theophylline is a drug commonly used in treatment of asthma.In our study, we found that a red intermediate which appeared and then disappeared immediately after we mixed Ce(IV) with theophylline. We have investigated this intermediate via rapid-scanning stopped-flow UV/Visible spectroscopy combined with single wavelength stopped-flow technique. Successive reaction kinetic simulation model has been used to study properties of the intermediate. A possible reaction mechanism is proposed.

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Novel Chemiluminogenic reaction is described for the sensitive determination of Arg-containing peptides. The reaction is based on fluorescence derivatization of the peptides with benzoin in a potassium hydroxide solution at 100°C for 2min, followed by chemiluminescence reaction with an aprotic polar solvent (N, N-dimethylformamide, dimethyl sulfoxide or acetonitrile) in the presence of hydrogen peroxide. The reaction conditions were established by employing Arg. Furthermore, fifteen kinds of benzoin analogues were examined under similar reaction conditions. Among them, benzoin, desyl bromide and 2′-chloro-3, 4-dimethoxybenzoin gave same levels of chemiluminescence intensities for Arg. These reagents are useful as chemilum- inogenic derivatization reagents for Arg-containing peptides as well as guanidino compounds; the detection limits are 5-20pmol/ml in the reaction mixture for the peptides under the established reaction conditions.

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A novel fluorescent indicator for anions, which contains both a fluorescent pyrenyl moiety and a thiourea group as a recognition site, is described. Hydrogen bond-mediated complexation with oxo anions such as CH₃COO^- and H₂PO₄^- induces a dual fluorescence consisting of two bands, namely, a normal emission due to the pyrene unit and an anomalous long-wavelength emission. The intensity of the new emission increases as anion concentration increases, while the normal emission is relatively unaffected. The degree of the changes is in the order of CH₃COO^->H₂PO₄^-_??_ClO₄^-, reflecting the binding selectivity of the probe molecule.

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The separation efficiencies of seven different neuropeptides, which contain three opioid peptides, were investigated by Capillary Zone Electrophoresis (CZE). The tested neuropeptides were β-endorphin, methionine-enkephalin, leucine-enkephalin, substance P, somatostatin, vasopressin, and oxytocin. They are related to the pain mechanism in the vertebrate central nervous system. The optimal conditions for separating the neuropeptides were as follows: 30mM citric acid buffer at pH 2.9, 75μm (I.D.) X 55cm fused silica capillary column, and 185nm wavelength UV detection. The developed CZE method was used to detect the neuropeptides in rat brain tissue homogenate, rat plasma and human plasma. Two neuropeptides, β-endorphin and substance P, were confirmed in rat brain, and opioid peptides such as β-endorphin, methionine-enkephalin and leucine-enkephalin were identified in rat plasma. Also, the three opioid peptides were not only identified but also quantitatively analyzed in human plasma. Quantitative analysis was achieved with the use of an internal standard. Recovery after sample preparation was good at 83-91%. Detection limits for these pioid peptides were 0.10pmol for β-endorphin and 0.25pmol for both methionine-enkephalin and leucine-enkephalin.

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Atomic absorption spectrophotometric method, for determination of arsenic and iron concentration in finger and foot muscles from Blackfoot Dim Patients(BFDPs), by amputation were developed. Thirty-four cases of BFDPs, at the most strict clinical examination and thirty cases of Non-BFDPs(NBFDPs) from the traffic accidents. NBFDPs from the same district were compared as the controls. Arsenic has been claimed to be major causative agents of Blackfoot Disease(BFD) in the south-western coast of Taiwan. We published several papers on this and presented a conception that, as with the increase in linical stages from the zero, first, second, third and fourth, the increase in the arsenic concentration in blood, hair and urine accompanies as the BFD progressed, although at the third and fourth stages, arsenic decrease might be induced by the antagonistic effect of selenium, zinc and iron. For the purpose to prove this, the study was carried out to check whether at the fourth stage, the concentration of arsenic in BFDPs finger and foot muscles by amputation are higher than that of NBFDPs and whether it is also the case with the blood of BFDPs . The arsenic in muscles of finger and foot of BFDPs by amputation was more than 10times higher than the NBFDPs at the raze of 0.80±0.57μg/g>0.07±0.05μg/g and they were also about 8times higher than the blood of BFDPs at the fourth clinical stages at the rate of 0.80±0.57μg/g>0.091±0.052μg/ml. Both of them had significantly difference with P<0.01. These evidences directly indicated that arsenic might be a major causative agent of BFD.supplementThe iron in muscles of finger and foot of BFDPs by amputation were also about 2times higher than that of NBFDPs at the rate of 39.63±23.54μg/g>19.82±7.61μg/g and had a significance difference with P<0.05. These results were on the contraiy to the blood, when compared with the blood iron concentration in BFDPs at fourth stage and NBFDPs. The NBFDPs were higher than the BFDPs at the rate of 553.28±92.96μg/ml> 510.71±163.52μg/ml. Therefore iron may have some antagonistic effect to arsenic toxicity for the BFDPs and this fact is worthy of more academic study of the BFD in clinical application.

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Atomic absorption spectrophotometric methods, developed for determination of arsenic, selenium and zinc concentration in finger and foot bone from blackfoot disease patients(BFDPs), by the amputation were developed. Thirty-four cases of BFDPs at the most strict clinical examination and thirty cases of Non-BFDPs(NBFDP) from the traffic accidents, nearly at the same condition were compared as control. Arsenic has been claimed to be a major causative agent of blackfoot disease(BFD) in the southwestern coast of Taiwan. Previously we published some reports also supported this conception, as with increasing of zero, first second, third and fourth clinical stages. The increasing of the arsenic concentration in the blood, hair and urine were happened during the BFD progressed. Although at the third and fourth stages, arsenic decreased may be affected by the antagonistic effect of selenium and zinc. For the purpose to this facts, this experiment was carried to check whether at the fourth stages, the concentration of arsenic in BFDPs finger and foot bone by amputation are higher than NBFDPs andeven in the blood of BFDPs at the fourth stage or not. The result showed arsenic concentration in finger and foot bone of BFDPs were a little higher than NBFDPs and with the rate of 0.09±0.05μg/g and 0.08±0.04μg/g. Zinc concentration in BFDPs finger and foot bone by amputation were lower than the NBFDPs and with the rate of 52.9±20.2μg/g>35.0±13.8μg/g and had a significantly difference with p <0.05. The same condition, happened to the BFDPs blood zinc and bone zinc. BFDPs had lower blood zinc concentration than bone zinc with the rate of 35.0±13.8μg/g>3.59±1.36μg/g. Selenium concentration of BFDPs in finger and foot bone by amputation were also had a lower selenium concentration than the NBFDPs and with the rate of 0.07±0.04μg/g<0.17±0.04μg/g. It had a significantly difference with p<0.01. Further more, when we compared selenium concentration of BFDP by amputation in finger and foot bone with the BFDP blood at the fourth stages. The results were on the contrary. The bone selenium concentration of BFDPs were higher than the BFDPs blood selenium with the rate of 0.08±0.05μg/g>0.04±0.02μg/ml and had significantly difference with p<0.05. Selenium and zinc may have some antagonistic effect with arsenic and from this stand point of the role, selenium and zinc as either inhibitory agents of BFD. Therefore selenium and zinc may assess in the blood as diagnostic or prognostic aids in BFD.

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The binding properties of several DNA ligands with calf thymus DNA have been studied by using capillary zone electrophoresis (CZE). The peaks of the ligands retarded with increasing concentration of DNA in carrier solution. The binding constants of the ligands with DNA were determined easily with high reproducibility from the slope of the (t-t₁)^-1 vs. [DNA-p]^-1, where t₁ and t are the migration time of the ligands in the absence and in the presence of DNA, respectively. In this procedure, only small quantities of the ligands and DNA samples were required. This binding assay was very convenient compared with conventional methods such as spectroscopic methods and equilibrium dialysis.

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The determination of odor recognition threshold values of n- and iso-amyl (pentyl) acetates was carried out by odor panel test (Japanese students 18-22 years old;6 males and a female) using 10- liter Tedlar bag static method. The trace concentrations of n-and iso-amyl acetates in the Tedlar bag were determined by gas chromatography and an odor sensor (SnO₂ type). The odor recognition threshold values of amyl acetates were 7.70ppm for n-amyl and 1.50ppm for iso- amyl. The odor quality from several odor panels were evaluated, such as a binder solvent-like, aqueous paint, stimuli, fruity, aromatic, ether-like, gasoline-like, pungent, minty, sour, petroleum- like, respectively.

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A water-soluble mercury(II) porphyrin was used as a photosensitizer in DNA cleavage. The nuclease activity of the sensitizer at subnanomolar concentration was investigated by the conversion of supercoiled (F-I) pBluescript plasmid DNA to open circular (F-II), linear (F-III) and small fragments DNA upon photoirradiation. The results indicated that the photocleavage of DNA was dependent on the concentration of sensitizer and irradiation time. Hydroxyl radical (•OH) and singlet oxygen (¹O₂) promoted DNA photocleavage. The formation of these active species during DNA photocleavage reaction was confirmed by the inhibitory effect of active oxygen scavengers and as well as by ESR measurement.

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