Chromatographic methods

Buxus latistyla Gagnep. (Buxaceae) has been used as a remedy for treating malaria, haemoptysis, amoebic dysentery etc. However, its chemical constituents are still unknown. Thus, the aim of this study was to identify phytochemicals isolated from this plant.

7p vifaye 20-09-2024 3 1   Download

In addition, this compound is volatile, resulting in a short repellent effect. Contributing to solve these problems, a high-performance liquid chromatography with diode array detection was developed for the simultaneous quantification of neral and geranial, two geometric isomers of citral.

10p tamynhan6 11-09-2020 14 1   Download

A simple and inexpensive method was developed using liquid - liquid extraction, together with high performance chromatographic method for determination of methoxyfenozide residues in grapes. The evaluated parameters include the extracts by distilled water and acetonitrile solvents. The method was validated using grapes samples spiked with methoxyfenozide at different fortification levels (0.05, 0.1 and 0.5 µg/g). Average recoveries (using each concentration three replicates) ranged 86-95 %, with relative standard deviations less than 5%, calibration solutions concentration in the range 0.

8p chauchaungayxua6 26-06-2020 11 2   Download

The trap was then heated to release volatile compounds including ethylmethylmercury into a GC-AFS for separation and detection. The instrumental detection limit was 4.8 pg Hg/L. The method can therefore be applied for the determination of methylmercury in water samples at ultra – trace.

8p elandorr 03-12-2019 21 1   Download

The procedure for determination of 238 U, 234 U, 232 Th, 230 Th and 228 Th nuclides by alpha spectroscopy was developed. Nuclides of uranium (U) and thorium (Th) were separated from the soil samples by chromatographic method. In the medium of 8 M nitric acid, U(VI) and Th(IV) were adsorbed on the Dowex 1 anion resin column. However, U(VI) was eluted from column by increasing the used volume of 8 M nitric acid. Th(IV) was eluted from the column with 50 ml HCl 9 M.

5p uocvong04 24-09-2015 37 2   Download

Petroleum mixtures consist primarily of relatively unreactive complex hydrocarbons covering a wide boiling range. Such mixtures are difficult to separate by most analytical techniques. Therefore, the petroleum industry has for many years played a leading role in the development of chromatographic methods of analysis. Since the last book specifically concerned with chromatographic analysis of petroleum appeared 15 years ago, numerous advances have been made including developments in liquid and supercritical fluid chromatography, ...

453p trua_nang 22-04-2013 110 15   Download

N-Glycans from glycoproteins of the worm stage of the human parasite Schistosoma mansoniwere enzymatically released, fluorescently labelled and analysed using various mass spectrometric and chromatographic methods. A family of 28 mainly core-a1–6-fucosylated, diantennary N-glycans of composition Hex3)4HexNAc6)12Fuc1)6 was found to carry dimers ofN,N¢-diacetyllactosediamine [LacdiNAc or LDN;

15p dell39 27-03-2013 38 4   Download

 Matched against a wide range of spectroscopic and chromatographic techniques, the techniques of electroanalytical chemistry find an important role for several reasons: – Electroanalytical methods are often specific for a particular oxidation state of an element – Electrochemical instrumentation is relatively inexpensive and can be miniaturized – Electroanalytical methods provide information about activities (rather than concentration)

19p qdung92ct 03-07-2012 76 5   Download