Bernd Wenclawiak

GC/MS-FID analysis of BSTFA derivatized polar components of diesel particulate matter (NBS SRM-1650) extract

SummaryHydroxy and acid compounds, present in the polar HPLC fraction number 8 from the NBS-SRM 1650 (diesel particulate extract) were derivatized with N,O-bis(trimethylsilyl)-trifluoroacetamide (BSTFA) to form the trimethylsilane (TMS) derivatives. This improved the gas-chromatographic separation to give an improved characterisation using GC-MS. TMS derivatives were only observed in the acid extract of an aliquot of HPLC fraction number 8 which had undergone an acid-base fractionation. A number of previously unidentified compounds in fraction 8 could be characterised using mass spectroscopy. Ion mass chromatograms, recorded at m/z 73, 89 and 147 were correlated with the total ion current (TIC) to identify derivatized compounds. Only single, two and three ring derivatized aromatics were observed. The compounds identified in this polar fraction of the extract included p-nitrophenol, benzoic acid, hydroxy-benzoic acids, hydroxy-benzaldehyde, hydroxy-phthalimide, benzene dicarboxylic acids, naphthalene dicarboxylic acids, anthracene/phenanthrene dicarboxylic acids and, for some of these, the C1 to C3 alkyl homologues. Several methyl esters were also observed including biphenyl dimethyl ester and benzene trimethyl ester.

Negative temperature gradients for density programming in supercritical fluid chromatography

Negative temperature programming using one to three ramps can be utilized to perform density programs in capillary and packed column supercritical fluid chromatography. This method is a less costly alternative to pressuredensity programming. A three step procedure is suggested to optimize the temperature-density program. The separation of wax and crude oil samples is shown.

Darstellung und Charakterisierung aller Platinmetall-8-Hydroxychinolate

SummaryThe preparation of all platinum metal 8-hydroxyquinolinates (oxinates) is described. The metal ligand ratio of the chelates was determined by elemental analysis, the method of Yoe Jones (Ru, Os, Ir, Pt), and secondary ion mass spectrometry (SIMS). The absorption spectra of all platinum metal oxinates were recorded. The stability of chloroformic solutions of the platinum metal oxinates against solutions of hydrochloric acid, sulfuric acid, and sodium hydroxide has been investigated.

Micro reversed phase liquid chromatography of Cd-, Ni-, Zn-, Cu-, Co-, Hg-diethyldithiocarbamates at picogram level

SummaryThe use of micro reversed phase columns (Polygosil C18) for the separation of metal DDTC chelates was investigated and applied to drinking water analysis.Three different eluents have been tested [70∶20∶10 (MeOH∶ H2O∶CHCl3); 80∶20 (MeOH∶H2O); 70∶30 (MeOH∶H2O)] at flow rates of 7 to 28gml/min. Eluent composition showed strong influence onk′ of Co(DDTC)2.The linear working curves fitted at least 3 decades with detection limit of 40–500 pg. Monitoring at λmax instead of 254 nm decreases the detection limits. The consume of eluent is 10 to 20 times less than with analytical columnes.Results of micro LC have been compared with predictible data of theoretical considerations.ZusammenfassungDie Anwendung von Mikro-RP-Säulen (Polygosil C18) für die Trennung von Metall-DDTC-Chelaten wurde untersucht und auf die Analyse von Trinkwasser angewendet. Drei verschiedene Eluentien [70∶20∶10 (MeOH∶ H2O∶CHCl3); 80∶20 (MeOH∶H3O); 70∶30 (MeOH∶H2O)] bei Fließraten von 7 bis 28gml/min wurden untersucht,k′ von Co(DDTC)2 wird von der Eluenszusammensetzung erheblich beeinflußt. Der lineare Meßbereich betrug mindestens 3 Dekaden mit einer Nachweisgrenze von 40–500 pg, die durch Detektion bei λmax statt bei 254 nm noch weiter gesenkt werden kann.Der Verbrauch an Eluens ist 10–20mal geringer als bei analytischen Säulen.Die Ergebnisse der Mikro-LC wurden anhand theoretischer Überlegungen mit den vorhersagbaren Daten verglichen.

Normal phase liquid chromatographic separation and structure determination of palladium-2,2,7-trimethyloctane-3,5-dionate

Abstract The two geometrical isomers of Pd(tod)2 have been separated by normal phase liquid chromatography. The major (cis) isomer has been characterized by X-ray crystallography. C22H38PdO4, monoclinic, space group P21/n, a = 11.585(4), b = 10.567(5), c = 20.262(5) A, β = 90.41(3)°, Z = 4, Dc = 1.27 g cm−1, R = 0.056, Rw = 0.079 for 2152 ‘observed’ reflections.

HPLC-SIMS off-line coupling for the determination of 8-hydroxyquinolinates and some other metal chelates

SummaryThe 8-hydroxyquinolates (oxinates) of Ru, Rh, Pd, Os, Ir, Pt, V, Cr, Mo, W, and Cr- and Hg-2,2,7-trimethyloctane-3, 5-dionates have been investigated and characterized with SIMS. For off-line coupling peak fractions from HPLC separations have been used to study and demonstrate the applicability of SIMS as a detection and characterization method in HPLC.