Liquid chromatography sulfur determination

Ethylenethiourea (ETU) is a toxic decomposition product/metabolite of alky-lenebis(dithiocarbamates). This compound could be generated during processing of treated crops at elevated temperature. Different chromatographic methods to determine the residue levels of ETU have been published. After extraction with methanol, clean-up on a Gas-Chrom S/alumina column and derivatization (alkylation) with bro-mobutane, ETU residues can be determined by GC with a flame photometric detector in the sulfur mode. Alternatively, ETU residues can also be determined by an HPLC method with UV detection at 240 nm or by liquid chromatography/mass spectrometry (LC/MS) or liquid chromatography/tandem mass spectrometry (LC/MS/MS) (molecular ion m/z 103). ... 

Y. Ogasawara, K. Ishii, T. Togawa, and S. Tanabe, Determination of sulfur in serum by gas dialysis/high performance liquid chromatography. Anal. Biochem. 215,13—IS (1993). 

Gimeno R.A. et al., 2002. Determination of polycyclic aromatic hydrocarbons and polycyclic aromatic sulfur heterocycles by high-performance liquid chromatography with fluorescence and atmospheric pressure chemical ionization mass spectrometry detection in seawater and sediment samples. J Chromatogr A 958 141. 

Determination of serum cortisone by reversed-phase liquid chromatography using pre-column sulfuric acid-ethanol fluorescence derivatization and column switching. (159)... 

The carboxin is extracted from the sample with acetone in a Soxhlet extraction apparatus and, after concentration of the extract, is determined via gas-liquid chromatography using a nitrogen-selective detector. The presence of carboxin is confirmed by the use of a sulfur flame photometric detector. Recoveries ranged from 73 to 80% (barley) and 73 to 78% (wheat). 

Free energies of activation for the enantiomerization of a series of iV-aryl-1,3,2-benzodithiazole 1-oxides 41 have been determined by dynamic high-performance liquid chromatography (DHPLC) on a chiral stationary phase <1999JOC1483>. From a comparison of experimental and computer-simulated chromatograms, the barriers to stereoinversion at sulfur were found to be around 80 kj mol 1 and relatively insensitive to effects from substituents in the iV-aryl group. 

Dash, K., S. Thangavel, N.V. Krishnamurthy, S.V. Rao, D. Karunasagar, and J. Arunachalam. 2005. Ultrasound-assisted analyte extraction for the determination of sulfate and elemental sulfur in zinc sulfide by different liquid chromatography techniques. Analyst 130 498-501. 

K. Kurosaka, A. Kuchiki, and H. Nakagawa, Determination of sulfur in pharmaceutical preparations using reversed-phase high-performance liquid chromatography, Chem. Pharm. Bull., 39 2138(1991). 

Nutritional and nutritional status markedly influence xenobiotic metabolism in laboratory animals. Microsomes were prepared from the livers of rats which had been fed chow or modified AIN-76 diets with or without oxidized or unoxidized sulfur amino acids for 7 days. The pattern of benzo(a)pyrene (BaP) metabolites formed by each microsomal preparation in the presence of a NADPH-generating system was determined using high performance liquid chromatography (HPLC). The results indicate that oxidized sulfur amino acids induce different forms of cytochromes P-450 in rat liver Which are reflected by different BaP metabolic profiles. 

E.W.J. Hooijschuur, Ch.E. Kientz, A.G. Hulst and U.A.Th. Brinkman, Determination of hydrolysis products of sulfur mustards by reversed-phase microcolumn liquid chromatography coupled online with sulfur flame photometric detection and electrospray ionization mass spectrometry using large-volume injections and peak compression, Anal Chem., 72, 1199-1206 (2000). 

The form of the dissolved sulfur has not been characterized properly yet. While stable at ambient temperatures, a substantial amount can be converted to crystalline sulfur at elevated temperatures or by solvent separation. This observation led to the development of a rapid liquid chromatography method to determine elemental sulfur in SA binders. The procedure which has been described previously by Cassidy (17) is based on gel permeation principle and uses a Styragel column and a uv detector. Results showed that 2-14% of the elemental sulfur added reacted chemically with the asphalt. Petrossi (18) and Lee (19), who determined free sulfur by extraction with sodium sulfite followed by titration with iodine, calculated a higher percent of bonded sulfur in sulfur-asphalt compositions. The observed differences are most likely caused by variations in the asphalt composition with regard to polar aromatics and naphthene components as well as by reaction temperature and contact time. 

The SA binder is tested for dispersion and particle size prior to mix production with a microscope. The binder level of the mix is constantly measured with a Troxler model 2226 asphalt content gauge. Hot solvent extraction (ASTM D2172) using tetrachloroethylene solvent can also be used to measure the binder content of a SA mix. The sulfur—asphalt ratio of the binder is monitored in the field with the Troxler or by density measurements. Other methods that can be used to measure SA ratios are x-ray fluorescence of solutions of sulfur-asphalt in tetrachloroethylene, liquid chromatography, and differential scanning calorimetry. X-ray fluorescence measures total sulfur, liquid chromatography determines elemental sulfur, and DSC monitors crystalline sulfur. 

Intensive research on elemental analysis has been carried out in this laboratory to overcome difficulties in determining nitrogen and sulfur in heavy fractions of petroleum or bitumens. With existing combustion techniques it was nearly impossible to obtain good overall balances for these elements when individual fractions coming from liquid chromatography were analyzed. Recoveries of 85%-95% of the quantity originally present in the... 

Thomas, D., S.M. Crain, P.G. Sim, and F.M. Benoit. 1995. Application of reversed phase liquid chromatography with atmospheric pressure chemical ionization tandem mass spectrometry to the determination of polycyclic aromatic sulfur heterocycles in environmental samples. J. Mass Spectrom. 30 1034—1040. 

Cyclohexane and benzene (Fisher spectranalyzed grade) and nitrous oxide and sulfur hexafluoride (Matheson) were used as supplied. The samples were thoroughly freed from dissolved air and frozen into the cells on a grease and mercury-free vacuum line. Hydrogen and nitrogen were measured using conventional vacuum line techniques and a mass spectrometer. Cyclohexene and bicyclohexyl were determined by gas liquid chromatography (16). 

The products from cumene hydroperoxide decomposition induced by organic sulfur compounds were determined by quantitative NMR except for phenol by high-pressure liquid chromatography and cumene hydroperoxide by iodometric titration (16). Cumyl alcohol is produced in the initial oxidation of sulfenic acid to sulfonic acid, and subsequently most of it is converted to a-methylstyrene as shown in Table II. The major products (40-45%) are phenol and acetone consistent with an acid-catalyzed decomposition of cumene hydroperoxide. Considerable... 

Dou, L. Krull, I.S. Determination of aromatic and sulfur-containing amino acids, peptides, and proteins using high-performance liquid chromatography with photolytic electrochemical detection. Anal.Chem., 1990, 62, 2599-2606... 

Selective separation of gold from many ions by liquid chromatography on columns of Amberlite XAD4 impregnated with (5,4-dimethylaminoben-zylidene-rhodamine) (DMABR) was achieved by Chien et al. [144]. Trace Au(III) (<0.1 ppb) was sorbed at pH 0-1 and was eluted by 0.02 M cyanide solutions at pH 7. Au can be determined in the eluate by atomic absorption or neutron activation. Mercury ions and various anions (thiosulfate, sulfur, iodide, etc.) interfere. 

Applications Food. Immunoassays, Techniques Enzyme Immunoassays. Infrared Spectroscopy Near-Infrared. Lipids Fatty Acids. Liquid Chromatography Food Applications. Microscopy Applications Food. Nitrogen. Nitrosamines. pH. Phosphorus. Proteins Foods. Sampling Theory Practice. Sulfur. Water Determination. X-Ray Absorption and Diffraction X-Ray Absorption. 

The glycosidic bond of glycolipids is readily hydrolyzed by acid, and the carbohydrates liberated can be analyzed by instrumental methods, e.g., gas chromatography (GC), liquid chromatography (LC), or colorimetric procedures can be used. In one colorimetric procedure, the total amount of hexose units in a glycolipid can be quantified by reaction with anthrone in concentrated sulfuric acid and determination by the absorbance at 635 nm. 

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