Simultaneous Determination Of Sulfur Research Articles

New approach to the determination phosphorothioate oligonucleotides by ultra high performance liquid chromatography coupled with inductively coupled plasma mass spectrometry

This text presents a novel method for the separation and detection of phosphorothioate oligonucleotides with the use of ion pair ultra high performance liquid chromatography coupled with inductively coupled plasma mass spectrometry The research showed that hexafluoroisopropanol/triethylamine based mobile phases may be successfully used when liquid chromatography is coupled with such elemental detection. However, the concentration of both HFIP and TEA influences the final result. The lower concentration of HFIP, the lower the background in ICP-MS and the greater the sensitivity. The method applied for the analysis of serum samples was based on high resolution inductively coupled plasma mass spectrometry. Utilization of this method allows determination of fifty times lower quantity of phosphorothioate oligonucleotides than in the case of quadrupole mass analyzer. Monitoring of 31P may be used to quantify these compounds at the level of 80μgL−1, while simultaneous determination of sulfur is very useful for qualitative analysis. Moreover, the results presented in this paper demonstrate the practical applicability of coupling LC with ICP-MS in determining phosphorothioate oligonucleotides and their metabolites in serum within 7min with a very good sensitivity. The method was linear in the concentration range between 0.2 and 3mgL−1. The limit of detection was in the range of 0.07 and 0.13mgL−1. Accuracy varied with concentration, but was in the range of 3%.

Analysis of Sulphur in Cultivated Soils by Inductively Coupled Plasma Atomic Emission Spectrometry

Abstract Because of the large number of soil samples routinely analysed at the Soil Analysis Service Ltd., there is a need for simultaneous determination of sulphur by inductively coupled plasma atomic emission spectrometry (ICP-AES). Calcium chloride is at present used to extract sulphur and ammonium acetate to extract calcium, potassium, magnesium and phosphorus. In this comparative study, based on 100 soil samples, calcium chloride and ammonium acetate were used as extractants in order to determine the amount of plant available sulphur in soil. The purpose was to study the potential and characteristics of ammonium acetate as an extractant for soil sulphur, and to explain discrepancies between this and the other method. The results obtained so far indicate that the ammonium acetate method is basically sound. Possibilities of a chemometric approach, applied in treating the results, are discussed.

Simultaneous determination of carbon and sulphur in geological material, using inductive combustion

The simultaneous determination of sulphur and total carbon in 0.1–0.5 g samples of geological material has been achieved, using a Leco ® induction furnace with slight modifications to conventional attachments. The analyses are accomplished by initial removal of sulphur dioxide by absorption and titration, followed by collection of carbon dioxide in a gravimetric absorber. Accuracy and precision are similar to established individual combustion techniques and high levels of sulphur do not interfere with the carbon determination. Total analysis time is reduced considerably and the lifetime of some absorption components is extended.

Simple procedures for the simultaneous microdetermination of sulphur and halogens in organic compounds

By suitable combination of vanadium pentoxide with lead chromate or elemental antimony as absorbants a simultaneous determination of sulphur and halogens in organic compounds is made possible. Substances containing nitrogen can also be analysed. Carbon dioxide does not affect the determination.

Simultaneous Determination of Sulfur and Phosphorus in Water by Neutron Activation Analysis.

The determination of both sulfur and phosphorus in solution by measurement of the total beta activity in terms of P/sup 32/ by neutron activation analysis is described. Sulfur and phosphorus may be determined in water by irradiation of two samples containing these constituents, one sample being shielded with cadmium foil and the other unshielded. The results indicate that phosphorus can be reasonably detected at the 0.01--10.0 ppm level, when sulfur is also in solution, without serious interference. Sulfur may be detected at a minimum concentration of 0.1 ppm if the phosphorus content in solution does not exceed 1.0 ppm. In natural water sulfur can be semiquantitatively detected in the range 100 to 200 ppm without serious error by the double irradiation technique.

Simultaneous determination of sulphur and chlorine in organic compounds

A method for the simultaneous determination of sulphur and chlorine on the same sample of an organic compound following a Schoniger flask combustion (or some other oxygen combustion procedure) is described. This is possible by combining the barium perchlorate titration of sulphate, using Thorin as indicator, with the mercurimetric titration of chloride using diphenylcarbazone as indicator. The micro-determination of sulphur using the former titration procedure is described fairly fully; the microdetermination of chlorine using the latter titration procedure has already been fully dealt with, and description is limited to its application to this double determination.