• Journal of the Korean Chemical Society
• /
• v.33 no.4
• /
• pp.406-412
• /
• 1989

Indirect photometric detection of aliphatic compounds such as alcohols, ketones and esters was investigated in high-performance liquid chromatography, These samples possessing nonchromophore or weak chromophore could be indirectly detected by a UV detector with addition of UV absorbing, p-chlorophenol or p-nitrophenol in mobile phase as detection reagent, and submicrogram detection limits were achieved. Some mixtures of samples were also able to be separated and quantitated with good resolution and comparatively high sensitivity under optimum conditions.

• YAKHAK HOEJI
• /
• v.34 no.3
• /
• pp.215-218
• /
• 1990

An ion chromatographic method based on indirect photometric detection of UV transparent anions was developed. Separation of anion was accomplished on strong anion exchange column (Waters SAX) using UV detector at 254 nm. Among examined UV-active additives (Dns-H, Dns-glu, Dnsser, Dns-val), Dns-glu showed the highest sensitivity. Studies on the effects of the pH and ionic strength of eluent revealed that the increase of pH and ionic strength of the eluent decreased capacity factor. The best eluent for the separation of acetate, fluoride, chloride, nitrate and bromide was $1\;{\times}\;10^{-4}M$ Dns-glu in 5 mM phosphate buffer (pH 6.30). The detection limit of chloride ion was 2.1 ng in this condition.

• Analytical Science and Technology
• /
• v.12 no.4
• /
• pp.341-345
• /
• 1999

The separation and determination of inorganic cations by a capillary zone electrophoresis was studied. Cations were separated by the capillary column and detected by indirect UV method. The running buffer of 0.03 M creatinine and 0.02 M-hydroxy isobutylic acid solution (pH 4.8) was used to improve the mobility of ions in the column. A potential of 18 kV was applied at anode. A complete separation of cations ranged within 15 min and detection limits were between 0.1 and 1.0 ppm. The applicability of the method for real samples was demonstrated.

• Analytical Science and Technology
• /
• v.11 no.3
• /
• pp.213-221
• /
• 1998

The determination of inorganic anions by capillary zone electrophoresis is reported. A ten component synthetic mixture of anions of bromide, chloride, fluoride, nitrite, nitrate, sulfite, sulfate, perchlorate, chlorate and chlorite was separated by the capillary column and detected by indirect UV method. The running buffer contained 5 mM ammonium dichromate, 10 mM ammonium acetate, 20 mM diethylenetriamine, 10% methanol solution at pH 9.3. A potential of 15 kV at the cathode (reversed polarity) was utilized for the separation of inorganic anions. A complete separation of anions was achieved in less then 10 min and the applicabilities of the method for the analysis of real samples was demonstrated. We compare the concentration of anions in toluene inhaled humen's urine and in postmortem bloods obtained by capillary zone electrophoresis and ion chromatograph.

• Analytical Science and Technology
• /
• v.8 no.4
• /
• pp.835-841
• /
• 1995

The quantitation of inorganic anions in various drinking waters were investigated using capillary electrophoresis(CE) and the results were compared with ion chromatography(IC). With CE, in contrast to IC, was demonstrated rapid analysis, good efficiency, a low detection limit and the low comsumption of a solvent and samples. CE analysis was used 5 mM sodium chromate(pH 8.0) containing 20 mM tetraalkylammoniumbromide at -25kV applied voltage with indirect UV detection at 254 nm. This results in exceedingly short analysis time within 3 min. with efficiencies approaching 200,000 theoretical plates. The coefficients of variants of migration time are less than 0.8% and those of peak area are less than 2.3%. Detection limits for quantitative determination were 300 ppb-50 ppm level. These optimum conditions are applicable to various samples without pretreatment.

• Analytical Science and Technology
• /
• v.12 no.2
• /
• pp.111-115
• /
• 1999

Single column anion chromatography by indirect UV detection was applied to the determination of 7 common anions($H_2PO_4^-$, $Cl^-$, $NO_2^-$, $NO_3^-$, $I^-$, $SO_4^{2-}$, $SCN^-$). A low capacity silica-based anion-exchange column(TSK guardgel QAE-SW; ca. 0.3 meq./g; 4.6 mm i.d${\times}$150 mm) was used. In separating common anions, we compared naphthalene trisulfonic acid(NTS) and naphthalene disulfonic acid(NDS) to find more sensitive, selective and rapid separation method. And cations and anions can be separated simultaneously in 0.20 mM NTS-5% acetonitrile-water.

• Journal of Korean Society for Atmospheric Environment
• /
• v.15 no.3
• /
• pp.327-333
• /
• 1999

Determination of chloride ion in concentrated NaOH solution by capillary electrophoresis has been studied. The analysis was performed by indirect UV absorption detection using chromate buffer at 254nm. The matrix effect of the sample has been observed so that the sensitivity in strong NaOH solutaion has decreased up to 10% of that in distilled water. The pH effect of the sample on the sensitivity of CE peaks has been investigated. The method for increasing the sensitivity have been investigated and the optimum pH and concentration of the buffer were 7.5 and 10mM, respectively. A cationic surfactant cetyltrimethylammonium bromide(CTAB), was added to a buffer solution in order to reverse the electroosmotic flow(EOF) in the capillary. This results in a short analysis time and better peak shapes. Using this optimum condition, the determination of chloride ion in real environmental sample has been performed, which is captured in strong NaOH absorbent prepared for absorbing gas from chimney. The standard addition method has been applied for the quantitative analysis, and it was obtained the good reproducibility.