Application of high-pressure liquid chromatography in inorganic analysis

Zusammenfassung Die Möglichkeiten zur Reversed-phase-HPLC von Metall-Dithiocarbamaten wurden systematisch untersucht. Außer den Diäthyldithiocarbamat-Chelaten wurden in die Untersuchungen die Tetramethylendithiocarbamate einbezogen. Als geeignet und voneinander trennbar erwiesen sich die Diäthyldithiocarbamate von Pb, Ni, Co, Cu and Hg sowie die Tetramethylendithiocarbamate von Cd, Pb, Ni, Co, Zn, Cu und Hg. Allen anderen Metallchelate dieser Gruppen zersetzen sich im chromatographischen System, ergeben unsymmetrische oder wegen zu geringer Retention nicht trennbare Banden. Die Ergebnisse aus der Reversed-phase-Chromatographie werden mit den bereits beschriebenen Trennmöglichkeiten mit der Adsorptions-Dünnschicht-Chromatographie und denen der Gas-Chromatographie verglichen und diskutiert.

---

Application of high-pressure liquid chromatography in inorganic analysisV. reversed-phase chromatography of metal diethyl-and tetramethylenedithiocarbamates

Summary The possibilities for reversed-phase HPLC of metal dithiocarbamates have been systematically examined. Beside the diethyldithiocarbamate chelates examined also included are the tetramethylenedithiocarbamates. The diethyldithiocarbamates of Pb, Ni, Co, Cu and Hg and the tetramethylenedithiocarbamates of Cd, Pb, Ni, Cl, Zn, Cu and Hg are suitable for this technique and have proved separable from one another. All other metal chelates of these groups are decomposed in the chromatographic system, give asymmetrical peaks or because of low retention unresolved bands. The results from the reversed-phase chromatography are discussed and compared with previously described separations using thinlayer adsorption chromatography and gas chromatography.

     

Application of high-pressure liquid chromatography in inorganic analysis

Zusammenfassung Die Diäthyldithiocarbamate der Elemente Se, Cr(III), Ni, Co, Pb, Cu und Hg sind für die reversed-phase-HPLC geeignet und lassen sich bis auf Pb und Cu mit einer mobilen Phase aus Methanol und Wasser in 20 Minuten an LiChrosorb RP-8 trennen. Die Möglichkeiten für eine quantitative Analyse mit einem UV/VIS-Detektor variabler Wellenlängeneinstellung werden beschrieben. Im Nanogramm-Bereich lassen sich vor allem die Elemente Se, Cr, Co und Ni als Carbamate empfindilich bestimmen.

---

Application of high-pressure liquid chromatography in inorganic analysisII. Separation of metal diethyldithiocarbamates by reversed-phase HPLC

Summary The diethyldithiocarbamtes of Se, Cr(III), Ni, Co, Pb, Cu and Hg are suitable for reversed-phase HPLC, and without Pb and Cu all can be separated on Li Chrosorb RP-8 in 20 min using a mobile phase of methanol-water. The possibilities for quantitative analyses with a UV/visible detector withvariable wavelength adjustment are described. At nanogram level especially the carbamates of Se, Cr, Co and Ni are sensitive determinable.

---

---

I. Mittcilung:G. Schwedt, Anorganische Spurenanalyse mit der Hochdruck-Flüssigkeits-Chromatographie am Beispiel des Selens, Z. Anal. Chem.288, 50 (1977).     

Identification and quantification of inorganic and organic selenium compounds with highperformance liquid chromatography

Selenium appears in the natural selenium cycle in the form of several organic and inorganic compounds. The biologically beneficial and deterimental effects of ‘selenium’ must be ascribed to particular selenium compounds. The identification and quantification of selenium compounds in biological and environmental samples is required for an understanding of the role of selenium. The high-performance liquid-chromatographic (HPLC) methods for the separation, identification and quantification of selenite, selenate, hydrogen selenide, methaneselenol, bis(organothio) selenides, trimethylselenonium salts, selenonamino-acids, selenium derivatives of carbohydrates, selenoproteins, selenonucleosides and other miscellaneous selenium compounds are summarized (193 references) and pertinent detection modes discussed. Advantages and disadvantages of the methods are pointed out. The literature is covered since 1974, the year of the first publication in this field.     

Reversed-phase partition high-pressure liquid chromatography of trace amounts of inorganic and organic mercury with silver diethyldithiocarbamate

Inorganic and organic mercury diethyldithiocarbamates have been separated by reversedphase partition high-pressure liquid chromatography. The mercury chelates were formed by an exchange reaction with silver diethyldithiocarbamate in chloroform, in the presence of acetate buffer (pH 5.0). The inorganic and organic mercury chelates in the extract were separated within 30 min on a 3.9 x 300 mm mu-Bondapak C(18) column. EDTA (10(-4)M) in methanol-water mixture (78:22 v v ) was used as eluent at a flow-rate of 0.5 ml min .     

Simplex optimization of the separation of phospholipids by high-pressure liquid chromatography

A simplex procedure is shown to be an efficient approach for solving separation problems. The best solvent ratio for the separation of phosphatidylcholine and sphingomyelin has been found by means of a two-dimensional simplex capable of expansion and contraction. A successful high-pressure liquid chromatography separation of lysophosphatidylcholine, phoaphatidylethanolamine, phosphatidylinositol, phosphatidylserine, phosphatidylcholine, sphingomyelin and phosphatidic acid was achieved with a 180-cm column packed with Corasil II and a solvent mixture of chloroform—methanol—ammonia (50.0:35.9:7.0, v/v/v).     

Capillary electrophoretic separation of inorganic and organic arsenic compounds

Capillary zone electrophoresis was used to separate arsenite, arsenate, dimethylarsinic and diphenylarsinic acid, methanearsonic acid, phenyl- and p-aminophenyl arsonic acid, phenylarsineoxide and phenarsazinic acid. Anionic and uncharged species were separated in a fused silica capillary with on-column UV detection at 200 nm. A 15 mM phosphate solution adjusted to pH 6.5 containing 10 mM sodium dodecylsulfonate served as background electrolyte. The influence of pH and applied voltage on separation efficiency, as well as the feasibility of identification of arsenic compounds in spiked urine, were investigated. Received: 18 March 1998 / Revised: 25 May 1998 / Accepted: 30 May 1998     

Capillary electrophoretic separation of inorganic and organic arsenic compounds

Capillary zone electrophoresis was used to separate arsenite, arsenate, dimethylarsinic and diphenylarsinic acid, methanearsonic acid, phenyl- and p-aminophenyl arsonic acid, phenylarsineoxide and phenarsazinic acid. Anionic and uncharged species were separated in a fused silica capillary with on-column UV detection at 200 nm. A 15 mM phosphate solution adjusted to pH 6.5 containing 10 mM sodium dodecylsulfonate served as background electrolyte. The influence of pH and applied voltage on separation efficiency, as well as the feasibility of identification of arsenic compounds in spiked urine, were investigated. Received: 18 March 1998 / Revised: 25 May 1998 / Accepted: 30 May 1998     

Determination of organic and inorganic mercury compounds by reverse-phase high-performance liquid chromatography after extraction of the compounds as their dithizonates

A sensitive and selective method is described for the simultaneous determination of inorganic and organic mercury compounds. The mercury compounds are extracted into toluene or chloroform with dithizone, and the dithizonates are separated by liquid chromatography on an ODS column. Complete resolution was obtained between methylethyl-, phenyl- and inorganic mercury with a mobile phase of THF/methanol (2:1) with 0.05 M acetate buffer pH 4 (62 + 38), containing 50 μM EDTA. The mercury chelates were detected spectrophotometrically at 475 nm. The detection limits were at the subnanogram level. The method is applicable to human urine, tap water and tomatoes.     

Liquid chromatography separation of organic acidic compounds

Summary The influence of ionic compounds added to an aqueous methanol eluent on the retention behaviour of sulphonic, carboxylic acids and of phenols is demonstrated. Absolute and relative retentions can be optimized by changing the water-methanol concentrations. The optimum conditions for the separation of technical important sulphonic and carboxylic acids (dye intermediates) are shown.     

Simultaneous separation of 17 inorganic and organic arsenic compounds in marine biota by means of high-performance liquid chromatography/inductively coupled plasma mass spectrometry

A method using high-performance liquid chromatography/inductively coupled plasma mass spectrometry (HPLC/ICP-MS) has been developed to determine inorganic arsenic (arsenite, arsenate) along with organic arsenic compounds (monomethylarsonic acid, dimethylarsinic acid, arsenobetaine, arsenocholine, trimethylarsine oxide, tetramethylarsonium ion and several arsenosugars) in fish, mussel, oyster and marine algae samples. The species were extracted by means of a methanol/water mixture and a dispersion unit in 2 min, with extraction efficiencies ranging from 83 to 107% in the different organisms. Up to 17 different species were determined within 15 min on an anion-exchange column, using a nitric acid gradient and an ion-pairing reagent. As all species are shown in one chromatogram, a clear overview of arsenic distribution patterns in different marine organisms is given. Arsenobetaine is the major compound in marine animals whereas arsenosugars and arsenate are dominant in marine algae. The method was validated with CRM DORM-2 (dogfish muscle). Concentrations were within the certified limits and low detection limits of 8 ng g(-1) (arsenite) to 50 ng g(-1) (arsenate) were obtained.     

Rapid estimation of trace amounts of ethylenimine by high-pressure liquid chromatography.

A rapid procedure utilizing high-pressure liquid chromatography is described for determining trace quantities of ehtylenimine down to 0.01 ppm. The basis for the method is the quantitative reaction of ethyleneimine with the 1,2-naphthoquinone-4-sulphonate ion (Folin's reagent) to give 4-(1-aziridinyl)-1,2-naphthoquinone. Compared with the spectrophotometric procedure, this method provides a high degree of specificity and sensitivity. The method has been employed to determine ethylenimine in the pyrolysis products of polyethylenimine.     

超临界流体色谱与高效液相色谱分离手性化合物的比较

超临界流体色谱(SFC)分离具有速度快、分离效率高、溶剂消耗少等优点,近年来在手性化合物的分离分析中得到诸多应用。本文对比研究了涂覆型多糖手性色谱柱在SFC和高效液相色谱(HPLC)上拆分24种手性化合物的差异。通过比较这些化合物在色谱柱上的保留时间和选择因子等发现多数化合物在SFC上的分离效率要高于其在HPLC上的分离效率,但HPLC对轴手性化合物的分离效率要优于SFC。SFC和HPLC的分离表现出一定的互补性,随着苯环侧链烷基的碳数增加,化合物在SFC上的保留逐渐增强,而在HPLC的保留却逐渐减弱。叶菌唑在使用SFC和HPLC分析时出现了洗脱顺序反转的现象。这些结果为SFC手性拆分提供了参考。     

Determination of bromine in organic compounds by high-performance liquid chromatography

A method is proposed for the determination of bromine in organic compounds (which may also contain chlorine and iodine) by oxygen-flask combustion of the compound followed by pre-column reaction of bromide with acetanilide and 2-iodosobenzoic acid to form 4-bromoacetanilide which is then chromatographed on an ODS column with a mobile phase of methanol: water, 65:35 v/v, detection at 240 nm, and 4-N-acetylaminotoluene as internal standard. The method is rapid and precise (RSD 相似文献   

Analysis of basic compounds by reversed-phase high-performance liquid chromatography using hybrid inorganic/organic phases at high pH

The retention and mass overload of five bases and a quaternary ammonium compound were studied on a bridged ethyl hybrid inorganic/organic phase (XBridge C18) over a pH range 2.7-12.0 using acetonitrile-phosphate and carbonate buffers. Some comparisons were drawn with results on a methyl hybrid (XTerra) phase. At low pH, rapid mass overload was observed with severe decreases in efficiency as sample mass was increased over the range 0.04-5 microg of solute. At intermediate pH (swpH 7.0), generally good peak shapes for small sample mass were still obtained on the ethyl hybrid, but with somewhat increased tailing of bases compared with swpH 2.7. At higher pH (swpH 10), good peak shape and improved loadability were obtained for moderately strong bases, due to their occurrence mostly as neutral species. However, stronger bases gave poor efficiency, attributed to interaction of the charged basic solute with increasingly ionised column silanol groups. Results were broadly similar on the methyl hybrid at swpH 10. At swpH 11, unusual profiles of increasing followed by decreasing efficiency were obtained on the ethyl hybrid for some bases as sample mass was increased; improved results were obtained at swpH 12. While the column loadability increased substantially at the highest pH studied, tailing for small sample mass was still more severe than at low pH, even though all compounds were <1% ionised in the mobile phase.