[Determination of electrosynthesized urea products by igh performance liquid chromatography based n porous graphitic carbon column].

Urea is a simple organic compound that is widely used in both the industry and daily life. Compared with conventional methods, the preparation of urea by electrochemical synthesis is more environmentally friendly and sustainable. However, after the reaction, low amounts of urea and high concentrations of inorganic ions, including [Formula: see text] concentration was achieved without interference.

[Ion chromatography-pulsed amperometry method for determination of trace hydrogen sulfide in air].

Hydrogen sulfide (HS) is a pervasive gaseous pollutant that emits the characteristic odor of rotten gas, even at low concentrations. It is generated during various industrial processes, including petroleum and natural gas refining, mining operations, wastewater treatment activities, and refuse disposal practices. According to statistics from the World Health Organization (WHO), over 70 occupations are exposed to HS, rendering it a key monitoring factor in occupational disease detection.

[Determination of inorganic anions and gluconate by two-dimensional ion chromatography].

A new two-dimensional ion chromatography method was developed to parallelly analyze two different types of samples with the application of valve switching technology-suppressed conductivity and pulsed amperometric analysis system, for concurrent determination of chloride, nitrite, sulfate, nitrate four inorganic anions and gluconate. The first dimensional chromatography was using Ionpac AG18+Ionpac AS18 anion analysis columns with a suppressed conductivity detector for the separation and detection of Cl-, NO2-, SO4(2-) and NO3-. Respectively, the elution was 5 and 20 mmol/L NaOH at an isocratic flow rate of 1.

[Determination of six anthraquinone compounds in soil by parallel type dual gradient high performance liquid chromatography].

A high performance liquid chromatography (HPLC) was established for the determination of six anthraquinone compounds, 1,8-dinitroanthraquinone, 1,5-dinitroanthraquinone, 1-aminoanthraquinone, anthraquinone, naphthalene, 1,4,5,8-tetrachlorodibenzo anthraquinone, in polluted soil of residential construction. In this method, by using an Ultimate dual gradient liquid chromatograph (DGLC), designing a set of parallel dual system and accepting two same Dikma Diamonsil C18 columns (150 mm x 4.6 mm, 5 microm) to cross-analysis, 41.

Characterization of mercury concentrations in snow and potential sources, Shanghai, China.

This work focused on quantifying the total mercury (HgT) and major ion concentrations in snow samples to understand the importance of this pathway and sources of Hg deposited in Shanghai, China. Rare snow event samples were collected at 26 sites within the city of Shanghai on February 18, 2006, January 27, 2008 and January 20, 2011. The sites were distributed among four main functional area types (i.

[Determination of glyphosate in heart blood of corpse by ion chromatography].

A method for the determination of glyphosate in human blood by ion chromatography was established. The protein in heart blood from a corpse was precipitated with acetonitrile. The large molecules and Cl(-) in the supernatant were removed by a Dionex OnGuard II RP column and a Dionex OnGuard II Ag column, respectively.

[Determination of trace anions in atmosphere absorption solution by ion chromatography with the application of online sample neutralization, column concentration and online standard addition].

A novel ion chromatographic method was developed to directly determine trace anion (Cl(-), NO2(-), NO3(-), SO4(2-)) in atmosphere absorption solution with incorporation of large volume injection, online sample neutralization, column concentration and online standard addition. After comparing the results in different valve switching times and the chromatograms using different online neutralizing columns, the optimum experimental conditions were established. The application of Inguard H online neutralizing column and Carbonate Removal Device (CRD 200) eliminated the matrices OH(-) and carbonate.

Determination of tricarboxylic acid cycle acids and other related substances in cultured mammalian cells by gradient ion-exchange chromatography with suppressed conductivity detection.

An ion-exchange chromatography method was established for simultaneously analyzing the tricarboxylic acid (TCA) cycle acids and other related substances in cultured mammalian cells, including citrate, cis-aconitate, isocitrate, alpha-ketoglutarate, succinate, malate, fumarate, oxaloacetate, trans-aconitate, phosphate, lactate and pyruvate. A Dionex 600 ion chromatograph with an ion suppressor and a conductivity detector, and an IonPac AS11-HC analytical column were employed. An NaOH gradient elution containing 13.