The solvent sublation using ion pairs of metal-2-naphthoate(2-HNph) and tetrabutyl ammonium ($TBA^+$) ion has been studied for the concentration and determination of ultra trace Bi(III), In(III) and Tl(Ⅲ) ions in water samples. The partition coefficients ($K_p$) and the extraction percentages of 2-HNph and the ion pairs to methyl isobutyl ketone (MIBK) were obtained as basic data. After the ion pair $TBA^+$·M$(Nph)_4^-$ was formed in water samples, the analytes were concentrated by the solvent sublation and the elements were determined by GF-AAS. The pH of the sample solution, the amount of the ligand and counter ion added and stirring time were optimized for the efficient formation of the ion pair. The type and amount of optimum surfactant, bubbling time with nitrogen and the type of solvent were investigated for the solvent sublation as well. 10.0 mL of 0.1 M 2-HNph and 2.0 mL of 0.1 M $TBA^+$ were added to a 1.0 L sample solution at pH 5.0. After 2.0 mL of 0.2%(w/v) Triton X-100 was added, the ion pairs were extracted into 20.0 mL MIBK in a flotation cell by bubbling. The analytes were determined by a calibration curve method with measured absorbances in MIBK, and the recovery was 80-120%.

The non-spectroscopic interference effects that occurred in inductively coupled plasma/mass spectrometry were studied for Ge, As and Se in human urine and serum. Many biological samples contain Na, K, Cl and organic compounds, which may cause the enhancement and depression on the analyte signal. The effect of 1% concomitant elements such as N, Cl, S, P, C, Na, and K on a 100 ㎍/L germanium, arsenic and selenium signal has been investigated by ICP/MS. The interference effects were not in the same direction. It appeared that concomitant elements such as Cl, S, and C induce an enhancement effect, whereas N and P did not show any significant effect. And, Na and K caused a depression. We have found a link between the abundance of analytes and the ionization potential of concomitant elements (eV), except carbon and nitrogen.

A novel copper(II) membrane electrode based on diphenylisocyanate bis(acetylacetone) ethylenediimine (DIBAE), as a new hexadentates Schiff's base was prepared. The electrode exhibited a Nernstian response for Cu$^{2+}$ ions over a wide concentration range (1.0 ${\times}$ 10$^{-1}$ to 1.0 ${\times}$ l0$^{-6}$ M) with a limit of detection of 6.0 ${\times}$ 10$^{-7}$ M (39 ppb). The sensor shows a fast response time (15s) and the membrane can be used for more than 4 months without observing any major deviation. The electrode revealed very good selectivity with respect to many cations including alkali, alkaline earth, transition and heavy metal ions. The proposed sensor could be used in a pH range of 3.0-7.5. It was applied to the direct potentiometric determination of copper in black tea, and in wastewater of copper electroplating samples. The electrode was also used in potentiometric titration of the copper(II) ion with EDTA.

A competitive enzyme-linked immunosorbent assay (ELISA) was developed for the quantitative detection of the organophosphorus insecticide bromophos. Three bromophos analogues (haptens) were synthesized and were coupled to carrier proteins to use as immunogens or coating antigens. Rabbits were immunized with either one of two haptens coupled to bovine serum albumin (BSA) for production of polyclonal antibodies, and the sera were screened against one of the haptens coupled to ovalbumin (OVA). Using the serum with highest specificity and an enzyme tracer, an antibody-coated ELISA was developed, which showed an $IC_{50}$ of 40 ng/mL with a detection limit of 7 ng/mL. The antibodies in this assay showed negligible cross-reactivity with other organophosphorus pesticides except with the insecticides chlorpyrifos and fenitrothion.

The resonance Raman spectra of trans-polyacetylene films doped heavily with electron donor (Na) and acceptor (HClO4) have been measured with excitation wavelengths between 488- and 1320-nm, and the relationships between the Raman excitation photon energies (2.54-0.94 eV) and its wavenumbers were discussed. We found the linear dependence of the Raman shifts with the exchanges of excitation photon energies. In particular, the Raman wavenumbers in the C=C stretching $(V_1$ band) showed a dramatic decrease with the increase in Raman excitation photon energies. In the case of acceptor doping, its change is larger than that of donor doping. The observed wavenumber (1255-1267 $cm^{-1}$) of the $V_2$ band (CC stretch) of Na-doped form is lower than that of the corresponding band (1290-1292 $cm^{-1}$) of its pristine trans-polyacetylene, whereas the contrary is the case for the HClO4 doped form (1295-1300 $cm^{-1}$). The origin of doping-induced Raman bands is discussed in terms of negative and positive polarons.

Polymeric membrane electrodes for acetate anion based on meso-(${\alpha}$,${\alpha}$,${\alpha}$,${\alpha}$)-5,10,15,20-tetrakis[2-(penta-fluorophenylurea) phenyl]porphyrin I and similar urea-functionalized porphyrins Ⅱ-Ⅳ as neutral ionophores were prepared. The membrane based on porphyrin I exhibits the best potentiometric properties in pH 6.0 rather than pH 7.0: linear stable response over a wide concentration range (6.0 ${\times}$$10^{-5}$-1.0 ${\times}$$10^{-2}$) with a slope of -59.6 mV/decade and a detection limit of log[CH3CO$O^-$] = -5.32. Selectivity coefficients obtained from the matched potential method (MPM) in pH 6.0 indicate that interferences of hydrophobic anions are very small for the membranes of porphyrins I and II having the strong withdrawing group. The electronic effect of urea-functionalized porphyrins and pH effect of buffer solutions are discussed on the potentiometric response.

For the development of immunodetection method of 4,4'-dichlorodipheny-2,2,2-trichloroethane (p,p'-DDT), a persistent and broad toxic organochlorine insecticide, various DDT derivatives were synthesized and characterized for the use of immunogens and the coating ligands for the antibody evaluation. The appropriate lengths of linkers were introduced to investigate more efficient DDT derivatives. Among these hapten derivatives, 2,2-Bis(4-chlorophenyl)acetic acid (DDA), 5,5-Bis(4-chlorophenyl)-5-hydroxypentanoic acid (DDHP) and 5,5-Bis(4-chlorophenyl)-5-chloropentanoic acid (DDCP) were conjugated with keyhole limpet hemocyanin (KLH) for the use of immunogen to produce antibodies. 6,6-Bis(4-chlorophenyl)-6-hydroxyhexanoic acid (DDHH) and 3-[6,6-Bis(4-chlorophenyl)-6-hydroxyhexanoylamino]propanoic acid (DDHHAP) in addition to above hapten derivatives were conjugated to ovualbumin (OVA) and bovine serum albumin (BSA) for the use of coating ligands to measure the titration level of antibody and the displacement of free analytes. Three matching pairs of antibodies and coating ligands were selected for the simultaneous detection of p,p'-DDT and its related compounds of DDA and 2,2-bis(4-chlorophenyl)-1,1-dichloroethylene (p,p'-DDE) by investingating the displacement of free analytes in an indirect ELISA. These were PAb #1 and coating ligand DDCP-OVA, PAb #1 and DDHHAP-OVA, and PAb #3 and DDHHAP-OVA. The most useful immunoreaction for DDT analytes were obtained using PAb #3 and coating ligand DDHHAP-OVA showing 3.4 ng/mL of lower limit of detection. These results indicated that titration level and free analytes displacement were greatly influenced by hapten derivatized and carrier proteins conjugated.

An efficient procedure for the synthesis of 6,7-dichloro-5,8-phthalazinedione (4) was developed in 49% overall yield via chloroxidation of 5,8-diaminophthalazine (8). And a series of its derivatives, 7-pyridinium-5,8-phthalazinedione-6-oxide (9), 6-chloro-7-phenylamino-5,8-phthalazinedione (10), 6,6-dimethoxy-6H-2,3,6b,11-tetraazabenzo[a]fluoren-5-one (11a), and 6,6-diethoxy-6H-2,3,6b,11-tetraazabenzo[a]fluoren-5-one (11b) have been synthesized.

The absolute stereochemistry of tetrin B (1), an antifungal antibiotic isolated from a soil actinomycete was determined by applying Rychnovsky analysis, the modified Mosher method, and CD exciton chirality to be 4R, 5R, 7S, 9R, 11S, 12R, 13S, 15R, 24S, and 25R.

Bright yellow ${(Y_{1-x}Gd_x)}_{3-z}{(Al_{1-y}Ga_y)}_5O_{12}:Ce_z$ phosphors were synthesized. White LED was obtained by the combination of non-absorbed blue emission from a blue L ED itself and yellow emission from ${(Y_{1-x}Gd_x)}_{3-z}{(Al_{1-y}Ga_y)}_5O_{12}:Ce_z$ phosphors. The crystal structures and optical properties of ${(Y_{1-x}Gd_x)}_{3-z}{(Al_{1-y}Ga_y)}_5O_{12}:Ce_z$ phosphors were investigated.

6-Nitroquipazine has higher binding affinity for SERT than other selective serotonin reuptake inhibitors. We have prepared 6-nitroquipazine based rhenium complexes which would lead to the development of potential SPECT imaging agents with $^{99m}Tc$ for 5-HT transporter.

Solvolytic rate constants at 25 $^{\circ}C$ are reported for solvolysis of chlorodithioformate (1) in binary mixtures of water with acetone, ethanol, methanol, methanol-d, 50%methanol-d/50%D2O, and 2,2,2-trifluroethanol (TFE), and also in TFE-ethanol mixtures. The Grunwald-Winstein plot shows that the three aqueous mixtures exhibit dispersions into separate line. The correlation is improved only slightly by additional parameters NT for solvent nucleophilicity and/or I for aromatic ring parameter. Rate ratios in solvents of the same $Y_cl$ value, having different nucleophilicity provide measures of the minimum extent of nucleophilic solvent assistance, and the value of 3.35 for $[$k_{40EW}$/$k_97TFE$]_Y$ (EW = ethanol-water), is consistent with an essentially SN1 reaction mechanism. This study has shown that the magnitude of l, m and h values associated with a change of solvent composition is able to predict the SN1 reaction mechanism. log(k/$k_o$) = mY + lN + hI

Sphingosine is known to regulate a wide range of cell physiology including growth, differentiation, and apoptosis. In this study, we examined the effect of sphingosine on the phospholipase D (PLD) activity in rat thymocytes. Sphingosine potently stimulated PLD in the absence of extracellular calcium, while depletion of intracellular calcium by BAPTA/AM treatment completely blocked activation of PLD by sphingosine. Sphingosine-induced increase of the intracellular calcium concentration was confirmed using a fluorescent calcium indicator Fluo-3/AM. A phosphoinositide-specific phospholipase C inhibitor U73122 partially inhibited the stimulation of PLD by sphingosine. When mouse PLD2 gene was transfected into mouse thymoma EL4 cells, which lack intrinsic PLD activity, sphingosine could stimulate PLD2 significantly while overexpression of human PLD1 had no effect. Taken together, the sphingosine-stimulated PLD activity in rat thymocytes is dependent on the mobilization of intracellular calcium and appears to be due to the PLD2 isoform.

A simple, sensitive and selective determination method of oxalate has been investigated based on the fluorescence enhancement of $Eu^{3+}$-TTA complex due to the formation of $Eu^{3+}$-TTA-oxalate ternary complex. An emission peak of $Eu^{3+}$-TTA, which is increased linearly with addition of oxalate, occurs at 610 nm in aqueous solution with excitation at 306 nm. The linear range of the calibration curve is 1 ${\times}$$10^{-6}$-8 ${\times}$$10^{-6}$ M and the detection limit is 1 ${\times}$$10^{-6}$ M. The effects of foreign ions were studied. The present method was applied to determine oxalate of two synthetic samples.

The kinetics of the addition of X-substituted benzylamines (BA) to Y-substituted Benzylideneacetylacetones (BAA) have been investigated in acetonitrile at $25.0^{\circ}C$. The reaction is studied under pseudo-first-order conditions by keeping a large excess of BA over BAA. The addition of BA to BAA occurs in a single step in which the addition of BA to $C_\alpha$ of BAA and proton transfer from BA to $C_\beta$ of BAA take place concurrently with a four-membered cyclic transition state structure. The magnitude of the Hammett ($p_X$) and Bronsted ($\beta_x$) coefficients are rather small suggesting an early tansition state (TS). The sign and magnitude of the cross-interaction constant, $p_{XY}$ (= -0.49), is comparatible to those found in the normal bond formation processes in the $S_N2$ and addition reactions. The normal kinetic isotope effect ($K_H/K_D$ > 1.0) and relatively low $\Delta$H^{${\neq}$}$ and large negative $\Delta$S^{${\neq}$}$ values are also consistent with the mechanism proposed.

Partially doped Aurivillius phases SrBi2N$b_{2-x}M_xO_9$ (M=Cr and Mo) were successfully synthesized and characterized. The extent of the substitution was limited at ~20 mole % because of the size differences between $Nb^{5+}$ and $Cr^{6+}$, and between $Nb^{5+}$ and $Mo^{6+}$. When the amount of substitution exceeded ~20 mole%, the phases began to collapse and the second phases were made. The dielectric constants of substituted compounds were enlarged nevertheless Cr or Mo is substituted. The increment is bigger in the Mo substituted compound than in the Cr doped one although the Nb(Cr)$O_6$ octahedra could be more strongly distorted than the Nb(Mo)$O_6$ octahedra since the ionic size difference between $Nb^{5+}$ and of $Cr^{6+}$ is much bigger than that between $Nb^{5+}$ and $Mo^{6+}$. Consequently, the dielectric constant of the substituted Aurivillius phase $Bi_2$A_{n-1}B_{n-x}M_xO_{3n+1}$$ depends on the extent of distortion of the B$O_6$ octahedra and more strongly on the polarizability of the metal.