Recent advances in the separation of oligo DNA fragments using capillary electrophoresis (CE) were reviewed with special emphasis on the historical aspects and possible applications of the technology in the near future. In the section on single strand DNA separation, the high resolution capability of CE was demonstrated by referring to the size separation of oligo DNA in which a 1 mer difference in size of several hundreds base-mer can be recognized by using a polyacrylamide gel-filled capillary or high viscosity buffer. In addition, a statistical analysis of the migration time of heterogeneous oligo DNA was shown. By employing Gauss's least square method, the estimated migration time of any known sequences having no secondary struture can be calculated with probable error of less than 0.08 min. The effect of the secondary structure on separation was shown. The possibility of using these secondary structure effects on migration time for doing SSCP (single strand conformation polymorphism) was indicated. The section on double strand DNA separation focussed mainly on the application of CE. The possibility of detecting a specific gene or points mutation, or doing genetic diagnosis and paternal analysis was shown by referring to example of CE application to PCR (polymerase chain reaction) product analysis, ARMS (amplification refractory mutation system) analysis, RFLP (restriction fragment length polymorphism) analysis, and VNTR (variable number of tandem repeat) analysis.

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Four carboxylic acids, acetic, valeric, lactic and formic acids were separated completely by elution with a 5× 10 ^-4 M phosphate eluent (pH 4.3) in an ion chromatography using resin-based ion-exchange columns (Dionex HPIC-AG4A and HPIC-AS4A) in series. The eluent was flowed at a rate of 0.8 ml/min and a conductivity detector was used. The sensitive determination of these carboxylic acids was achieved by use of a cationexchange micro membrane suppressor in H⁺ form, in which each carboxylate species was converted into its acid molecule and the sodium dihydrogenphosphate eluent into ionized phosphoric acid (H₂PO₄^- and H⁺ ). The chromatograms obtained for the carboxylic acids showed negative peaks based on a decrease in the conductivity from the background level. When a 50 μl sample solution was injected, the observed detection limits at S/N=2 were 14.2 ppb for acetic acid, 40.5 ppb for valeric acid, 45.4 ppb for lactic acid. and 30.6 ppb for formic acid. The proposed method proved to be applicable to the determination of lactic acid in various food samples.

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High-performance liquid chromatography for trace amounts of manganese(II), cobalt(II), copper(II) and zinc(II) in water samples utilizing organic solvent extraction of α, β, γ, δ-tetrakis(4-carboxyphenyl)porphine(TCPP) complexes was studied. The metal-TCPP complexes were resolved and detected by reverse phase HPLC with a photometric detector. The absorption spectra of these complexes differed with the kind of metal ion combined with TCPP. A photo-diode array detector was therefore useful for accurate spectroscopic identification of the complexes. One milliliter of a buffer solution(ammonium-ammonium chloride, pH: 9.0) and 0.3 ml of a Cd-TCPP solution were added to 525 ml of a sample solution containing less than 1 μg of manganese(II), cobalt(II), copper(II) and zinc(II), respectively, to form the metal-TCPP complexes. The pH of the solution was adjusted to 3.5 with dilute hydrochloric acid and a buffer solution(hydrochloric acid-potassium chloride, pH: 3.5), and then 0.5 ml of tributyl phosphate (TBP) was added to the solution. The metal-TCPP complexes were extracted into the TBP phase. After 5 min centrifugation the TBP phase was mixed with acetonitrile in the ratio of 1 : 1, and a 20 μl potion of the solution was injected into the reverse phase HPLC system. The composition of the mobile phase was as follows: 70 (0.1 mol dm^-3 lactic acid): 30(acetonitrile): 1(TBP). The absorbances were measured over the range of 400 to 480 nm. The flow rate of the mobile phase was 1.0 ml/min. All components (TCPP and metal-TCPP complexes) injected were eluted within 12 min. Organic solvent extraction into TBP was given a high concentration factor (50 times). The detection limits (S/ N=3) of manganese(II), cobalt(II), copper(II) and zinc(II) were 0.6, 0.4, 0.6 and 0.16 ppb, respectively. The relative standard deviation of six measurements for the determination of those metal ions in tap water containing 14.4 ppb copper(II) and 8.8 ppb zinc(II) was 47.5%.

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A quantitative method to evaluate desorbed gasses from ULSI materials has been investigated by thermal desorption spectrometry using a quadrupole mass spectrometer. Thermal desorption studies for hydrogen ion implanted Si wafers exhibited good reproducibility of measurements. The reproducibility of the H₂ desorption peak area in the thermal desorption spectra was found to be within 5% of relative standard deviation between measurements for the 5×10¹⁴ H₂/cm² sample. Also a good calibration curve was established between the peak area and the amount of implanted hydrogen, ranging from 10¹⁵ to 10¹⁶/cm². The quantitative analysis of H₂ desorption revealed that HF treated Si(001) surfaces were almost perfectly terminated by hydrogen. It was also confirmed from desorption analysis of ULSI materials that inorganic desorbed species can be quantitatively evaluated by using the calibration curve and by taking into account of fragmentation factor, ionization probability and transmission factor in mass spectrometry, and pumping speed for the desorbed gasses. The detection limit was approximately 1×10¹³/cm², even for H₂ and H₂O. This work demonstrated a successful application of thermal desorption spectroscopy to quantitative analysis of species in the range of 10¹³10¹⁷/cm² from ULSI materials.

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A system to identify mineral components from near-infrared spectra by applying a neural network technique was examined. Reflective spectral data at 240 wavelength points for the wavelength range between 1300 and 2400 nm were entered into the input layer of a three-layered neural network trained by the error-back-propagation method. Spectra of various kinds of pure and mixed samples were used for the training, and the mineral components contained in the test samples were examined. As a result, a neural network to identify six kinds of mineral components with a probability of nearly 100% was constructed, and the possibility to develop a system to identify mineral components rapidly is demonstrated.

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A simple and rapid method was developed for sampling metals such as Na, Al, Ca, Cr, Fe, Ni, and Cu on the silicon wafer surface and for determination of these trace metals by graphite furnace AAS. Whereas a poor recovery was obtained for copper when using only HF as the dissolving reagent, a mixture of 0.1wt% HF and 1 wt% H₂O₂ was found to oxidize the silicon and dissolve the copper to improve the recovery to nearly 100%. It is important to keep the silicon dioxide thickness greater than ca. 0.1 nm by controlling such factors as temperature and concentration of HF and H₂O₂. However, the sensitivity of aluminum was decreased by interference from hydrofluoric acid. It was improved by drying in the presence of magnesium as an effective modifier. For a 6 inch wafer, this method is easily applicable to the determination of 10⁹10¹⁰atoms/cm² for metals.

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The formation constants of glycolchitosan-poly (vinyl sulfate) (GC-PVS) and glycolchitosan-dodecylbenzene sulfonate (GC-DBS) were determined by pH measurement. Their reactions were analyzed by an expansive application of the Zimm-Bragg model. When the concentration of coexisting salt (NaCl) was low, the apparent formation constant of GC-PVS was independent of pH and the reaction ratio, except for the coagulation region near 100% of the reaction ratio. In spite of the reaction between the two polymers, the reaction conditions did not change over a wide range of the reaction ratio. With increasing concentrations of coexisting salt, the formation constant varied with pH and the reaction ratio, and the ion-association reaction was depressed. On the other hand, the apparent formation constant of GC-DBS varied and was smaller than that of GC-PVS. It was considered that DBS did not bind alone to GC, but rather reacted with GC as an aggregate. The stoichiometry of colloidal titration of GC-PVS was estimated using the formation constant, log K_i=6.2, in which the total concentrations of GC and PVS are 5×10^-4 equiv (chemical equivalent per dm^-3), respectively. The value of the formation constant was far smaller than a sufficient value consistent with the result of the colloidal titration of GC-PVS. The inconsistency was made up by considering the coagulation which occurred near 100% of reaction ratio. That is, the stoichiometric accuracy of the colloidal titration may be due to the coagulation of a polyelectrolyte complex with removal of coexisting ions and dehydration.

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In this study, an analytical method of hydrocarbon composition determination has been developed to improve the repeatability of low concentration gaseous hydrocarbon measurement of automotive exhaust gas. Gas components of ppb order level are analyzed by GC with a large volume gas loop and direct focus trap with liquid nitrogen. Water vapor in automotive exhaust is separated by packed column/capillary columnmulti dimension GC. Repeatability of this method is about 1%, and water vapor is back flushed by packed column GC.

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Absorption and fluorescence properties of chlorophyll a and b and pheophytin a and b in aqueous solutions of six species of nonionic surfactant were examined, respectively. The interaction between chlorophyll and surfactant was considered using two parameters; molecular refraction and inorganicity/organicity ratio. Chlorophyll was most soluble in Triton X-100 [average addition molar number of ethylene oxide (EO) group: n=9.5] solution or polyoxyethylene mono-p-octylphenylether [n=10] (POOPE-10) solution. Chlorophyll a and b had larger solubilities in the surfactant solutions than did pheophytin a and b. However, the molar extinction coefficients and fluorescence quantum yields of the chlorophylls in the surfactant solutions were smaller than those in organic solvents, such as acetone. Consequently, the interaction between the magnesium of chlorophyll and the oxygen atom on the EO chain and labilization of the excited states of chlorophyll by water molecules became apparent.

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A high-performance liquid chromatographic (HPLC) method for the determination of a local anesthetic, lidocaine, in human blood, human plasma and human serum albumin(HSA) solution was developed. Lidocaine extracted from blood was analyzed by the HPLC method on a reversed-phase column using an eluent consisting of 50 mM potassium dihydrogenphosphate-acetonitrile (3 : 1) and UV detection at 220 nm. Sample solution for HPLC was prepared as follows. Lidocaine in human whole blood (0.51 ml) was directly extracted with diethyl ether (5ml). The extract (3 ml of organic layer) was evaporated to dryness in a stream of nitrogen gas at 60°C. The dried residue was dissolved in 500μl of eluent and then 100μl of this solution was injected into the HPLC system through a disposable filter (pore size of 0.45μm). The calibration curves for the human whole blood, human plasma and HSA solution were linear (γ>0.9996) over the concentration range of 0.220μM of lidocaine. The lidocaine in human whole blood could be successfully determined from the calibration curve with a standard lidocaine solution. The recoveries of lidocaine from the solution of 10μM were almost 100% for human blood, human plasma and HSA solution. The relative standard deviation (%) was less than 4% in the concentration range of 220μM of lidocaine. No interference from other endogenous blood constituents was observed. This method was applied to determination of lidocaine in rabbit blood.

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To determine blood urea accurately in uremia patients, a simple analytical procedure combining a solid phase extraction (SPE) and high performance liquid chromatography (HPLC) was studied. SPE was performed using Bond Elute SCX (resin weight, 500 mg; resin volume, 2.8 ml) which was conditioned with 3 ml of methanol followed by 3 ml of water and eluted with 4 ml of 5% phosphate solution. For HPLC, MCIgel CKO8S (4.6×150 mm) was eluted with 1mM HCl at a flow rate of 1 ml/min and column temperature at 35°C with detection at 200 nm. By comparing ultrafiltrated blood urea and native blood urea, the blood urea from the HPLC chromatogram was found to be completely free of blood admixtures and almost free of blood protein. We concluded that the current clinical method of blood urea determination which uses an ammonia selective electrode could be replaced by our method which is more selective and provides more accurate and reliable data for diagnosis.

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Catalytic analysis of copper(II) was investigated by measuring a highly fluorescent 3, 3'-diformyl-2, 2'-dipyridyl formed in the copper(II) catalyzed oxidation of 1, 10-phenanthroline with hydrogen peroxide. Therefore, copper(II) ion was determined indirectly by fluorometry. The recommended procedure is as follows : Take 10 ml of sample solution containing less than 0.3μg of copper ion. Add 2 ml of 7.5×10^-3 M 1, 10-phenanthroline and 5 ml of 0.1 M Na₂B₄O₇ buffer solution to the sample solution. Adjust the pH to 11.5 with sodium hydroxide solution. Add 1 ml of 11.5% hydrogen peroxide solution. Dilute the solution to 25 ml with distilled water. The pH of the resultant solution is adjusted to 10.4. Allow the solution to stand for 10min at 40°C. Measure the fluorescence intensity of the final solution at 430 nm with an exciting wavelength of 330 nm. The possible range of determination is from 0.02 to 0.25μg. The proposed method was applied to the determination of copper(II) in tap water. The results were in good agreement with determinations by flame-less AAS.

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Temperature increases of the atomic vapor in the presence of matrix modifiers were studied under different atomization conditions. In rapid atomization, the atomic vapor temperatures of Pb and In in the presence of Pd modifier were increased by 400°C compared with those in the absence of the modifier. These phenomena were not observed in slow atomization. The change of the free energy and the vaporization by an endothermic reaction due to a decrease in the activity coefficient of the analyte metal in the alloy were presumed to be the cause for the temperature increases.

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The differential chromatogram method was useful to reduce large changes in background response in single column ion chromatography using stepwise elution. Cations (Na⁺, K⁺, Mg²⁺ and Ca²⁺) were separated on a cation exchange column by stepwise elution using both 0.01 mM and 3.0 mM copper sulfate eluents and detected at 230 nm by indirect photometry. Anions (lactate, acetate, propionate, formate, citrate, Cl^-, NO₂^-, Br^-, NO₃^-, SO₄^2-, S₂O₃^2- and I^-) were separated on an anion exchange column using both 0.3 mM and 1.5 mM disodium phthalate eluents and detected at 270 nm. This method was also successfully applied to conductometric detection.

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