Extraction Chromatographic Separation Research Articles

Ultra-Performance Liquid Chromatography with Electrospray Ionization Mass Spectrometry for the Determination of Coenzyme Q10 as an Anti-Aging Ingredient in Edible Cosmetics

A simple and rapid method for the determination of coenzyme Q10 in edible cosmetics was developed and validated. Cleanup utilizing a solid-phase extraction technique provided a simple and reliable method for extracting both coenzyme Q10 and its internal standard coenzyme Q9 from the lecithin-rich samples with efficiencies of 92 ± 4% and 89 ± 3%, respectively. The separation of analytes through a reversed-phase C18 column was carried out within 10 min. By employing authentic coenzyme Q10 and the internal standard spiked into blank matrices, the combined use of solid phase extraction cleanup and chromatographic separation coupled with electrospray ionization-tandem mass spectrometry detection was shown to be sufficiently accurate to detect coenzyme Q10 in edible cosmetic matrices. The limit of quantification of coenzyme Q10 determined by the validated method was 54 ng/g in the matrices. In addition, the intra- and inter-day precision was <4% and the accuracy ranged from 87.1 to 92.3%. Quantitative results for coenzyme Q10 levels in two different edible cosmetic samples obtained by the established analytical protocol were reproducible. This is the first report of the determination of coenzyme Q10 in lipophilic edible cosmetic matrices by liquid chromatography–electrospray ionization tandem mass spectrometry.

Recovery of uranium, thorium and zirconium from allanite by extraction chromatography using impregnated chromosorb

Chromosorb 102 impregnated with Cyanex 923 was used as a stationary phase in the extraction chromatographic separation of lanthanides, U(VI), Th(IV) and Zr(IV). Batch studies were carried out to investigate the uptake behaviour of these metal ions, along with few other metal ions. The effect of different parameters like equilibration time, concentration of acid, metal ions and extractant has been studied. The distribution data has been used to develop suitable eluting agents. The sorbing and desorbing capacity of the column for U(VI), Th(IV) and Zr(IV) was determined. Results indicate an insignificant change in the efficiency of the column up to 10 such cycles. The practical utility of the column has been demonstrated by the recovery of around 95% of U(VI), Th(IV) and Zr(IV) from allanite sample with a purity of around 97%±2%.

Extraction Chromatographic Method of Preconcentration, Estimation and Concomitant Separation of Vanadium (IV) with Silica Gel-Versatic 10 Composite

A selective method has been developed for the extraction chromatographic separation of V(IV) with SSG-V-10 composite. V(IV) was quantitatively extracted at pH 5.0-6.0, and its loading has been confirmed by EDAX. XRD studies indicate that the SSG network does not get influenced by impregnation with V-10 or by the sorption of V(IV) on the surface of SSG-V-10 composite. The binding between SSG and V-10 is a hydrophobic interaction only, and it takes place at the surface of the hydrophobic SSG. TGA-DTA analysis indicates its thermal stability up to 45°C. The exchange capacity (1.65 meq of H(+) g(-1)), break-through capacity (34.5 mg g(-1)) and column efficiency (360) of the extractor have been rationalized by Brunauer-Emmett-Teller analysis (SA = 149.46 m(2) g(-1) and PV = 0.2001 mL g(-1) at a relative pressure of 0.9-1.0). The sorption process was endothermic (ΔH = 12.63 kJ mol(-1)), entropy gaining (ΔS = 0.271 kJ mol(-1) K(-1)) and spontaneous (ΔG = -68.241 kJ mol(-1)) in nature. Preconcentration factor has been optimized at 182.3 ± 0.2. Formation constants (Kf) of the metal centers [Zn(II) (0.6 × 10(3)), Cd(II) (0.9 × 10(4)), Pb(II) (0.6 × 10(5)), Cu(II) (0.2 × 10(5)), Al(III) (6.2 × 10(5)), Ga(III) (4.2 × 10(5)), Hg(II) (2.2 × 10(6)), Bi(III) (6.2 × 10(6)), Tl(III) (8.9 × 10(6)), Zr(IV) (6.8 × 10(9)), Fe(III) (0.9 × 10(9)) and V(IV) (0.8 × 10(6))] have been determined. The desorption constants Kdesorption (1.9 × 10(-2)) and [Formula: see text] have been determined. Rf values and selectivity factors for diverse metal ions have been determined. V(IV) has been separated from the synthetic and real samples containing its congeners. A plausible mechanism for the extraction of V(IV) has been suggested.

Sequential Injection Approach for Simultaneous Determination of Ultratrace Plutonium and Neptunium in Urine with Accelerator Mass Spectrometry

An analytical method was developed for simultaneous determination of ultratrace level plutonium (Pu) and neptunium (Np) using iron hydroxide coprecipitation in combination with automated sequential injection extraction chromatography separation and accelerator mass spectrometry (AMS) measurement. Several experimental parameters affecting the analytical performance were investigated and compared including sample preboiling operation, aging time, amount of coprecipitating reagent, reagent for pH adjustment, sedimentation time, and organic matter decomposition approach. The overall analytical results show that preboiling and aging are important for obtaining high chemical yields for both Pu and Np, which is possibly related to the aggregation and adsorption behavior of organic substances contained in urine. Although the optimal condition for Np and Pu simultaneous determination requires 5-day aging time, an immediate coprecipitation without preboiling and aging could also provide fairly satisfactory chemical yields for both Np and Pu (50-60%) with high sample throughput (4 h/sample). Within the developed method, (242)Pu was exploited as chemical yield tracer for both Pu and Np isotopes. (242)Pu was also used as a spike in the AMS measurement for quantification of (239)Pu and (237)Np concentrations. The results show that, under the optimal experimental condition, the chemical yields of (237)Np and (242)Pu are nearly identical, indicating the high feasibility of (242)Pu as a nonisotopic tracer for (237)Np determination in real urine samples. The analytical method was validated by analysis of a number of urine samples spiked with different levels of (237)Np and (239)Pu. The measured values of (237)Np and (239)Pu by AMS exhibit good agreement (R(2) ≥ 0.955) with the spiked ones confirming the reliability of the proposed method.

Chemical composition and evaluation of mosquito larvicidal activity of &amp;lt;i&amp;gt;Vitex payos&amp;lt;/i&amp;gt; extracts against &amp;lt;i&amp;gt;Anopheles gambiae&amp;lt;/i&amp;gt; Giles S.S larvae

AIM: The aim of this study was to evaluate the acetone and methanol root bark extracts of Vitex payos and different fractions thereof, following acetone extraction and column chromatographic separation, for their immediate toxicity and long term effects on An. gambiae Giles sensu stricto larvae under semi-field conditions. MATERIALS & METHOD: Third and early fourth instars of An. gambiae larvae were exposed to acetone and methanol extracts of V. payos root bark and the acetone chromatographic fractions. Their effects on larval, pupal and adult stages were recorded. Consequently, GC/MS analysis on the extracts was carried out. RESULTS: Larvicidal effects of the extracts and fractions were found to be largely associated with phytoecdysteroids and saponins which tested positive in the test materials. The fractions were more potent than the crude extracts. Long-term (11-14 days) post-exposure observations at lower doses showed that the extracts achieved over 90% adult growth inhibition with morphogenetic variations and behavioral changes. CONCLUSION: Extracts and chromatographic fractions from V. payos possess larvicidal and/or IGR principles which can be used in the local communities where most of the people cannot afford synthetic larvicides.

Экстракционно-хроматографическое выделение и разделение тория, урана, нептуния и плутония сорбентами, импрегнированными фосфорилподандом кислотного типа и его смесями с нитратом метилтриоктиламмония

Экстракционно-хроматографическое выделение и разделение тория, урана, нептуния и плутония сорбентами, импрегнированными фосфорилподандом кислотного типа и его смесями с нитратом метилтриоктиламмония

Rapid Determination of Technetium-99 in Large Volume Seawater Samples Using Sequential Injection Extraction Chromatographic Separation and ICP-MS Measurement

An automated method was developed for rapid determination of (99)Tc in large volume seawater samples. The analytical procedure involves preconcentration of technetium with coprecipitation, online separation using extraction chromatography (two TEVA columns) implemented in a sequential injection setup, and measurement of (99)Tc by inductively coupled plasma mass spectrometry (ICP-MS). Chromatographic behaviors of technetium, molybdenum, and ruthenium were investigated, and the mechanism of adsorption and elution of TcO(4)(-) on a TEVA column using HNO(3) was explored. The results show that not only NO(3)(-) but also acidity (or concentration of H(+)) of the loading or eluting solution affect the adsorption and desorption of TcO(4)(-) on TEVA resin. Decontamination factors of more than 1 × 10(6) for ruthenium and 5 × 10(5) for molybdenum are achieved. Chemical yields of technetium in the overall procedure range from 60% to 75% depending on the sample volumes, and a detection limit of 7.5 mBq/m(3) (or 11.5 pg/m(3)) for 200 L of seawater was obtained. Compared with the conventional analytical procedure, the developed method significantly reduces analytical time. A batch of samples (n > 4) can be analyzed within 24 h. The method has been successfully applied for rapid and automated determination of low level (99)Tc in large volume seawater samples. The analytical results of seawater samples collected in Denmark show a good agreement with the values obtained using the conventional method.

Extraction-chromatographic isolation of 90Y for medical purposes

A procedure is described for isolating 90Y from its equilibrium mixture with 90Sr. It is based on extraction-chromatographic separation of 90Sr and 90Y on columns packed with a solid extractant based on di-2-ethylhexyl hydrogen phosphate. Further purification of 90Y is made by its sorption on a column with an yttrium-specific sorbent based on octyl(phenyl)-N,N-diisobutylcarbamoylmethylphosphine oxide in TBP, and then on a cation-exchange resin. The whole process is performed in a nitric acid solution, which, in contrast to hydrochloric acid solutions, does not cause strong corrosion of stainless steel equipment, thus facilitating decontamination of the final product from inactive impurity cations.

Method development for 234U and 230Th determination and application to fossil deep-water coral and authigenic carbonate dating from the Campos Basin - Brazil

A 234U and 230Th determination method based on an extraction chromatographic separation followed by ICP-MS with quadrupole (ICP-QMS) was developed. For authigenic carbonates, a second separation step with ion exchange chromatography in a HNO3 solution was added. These methods were applied to seven fossil deep-water coral and two authigenic carbonate samples from the continental slope of the Campos Basin - Brazil. The ages determined for the fossil corals samples from the same sediment core ranged from 9 to 202 ky with a 1% uncertainty, consistent with the values determined by 14C dating and with those determined by 230Th/234U using flow injection coupled to an ICP-QMS. One of the authigenic carbonates analyzed presented an age of approximately 80 ky. The other sample exhibited a 230Th/234U activity ratio close to equilibrium and out of the application range of the method.

Stability of Technetium and Decontamination from Ruthenium and Molybdenum in Determination of 99Tc in Environmental Solid Samples by ICPMS

A rapid and efficient method for the determination of (99)Tc in environmental solid samples was developed using chromatographic separation combined with inductively coupled plasma mass spectrometry (ICPMS) measurement. The volatility of technetium during sample ashing and solution evaporation was investigated to establish a reliable sample pretreatment procedure. A novel approach was developed to improve the removal of molybdenum and ruthenium in chromatographic separation using 30% H(2)O(2) pretreatment of the loading solution and extraction chromatographic separation using two serial small TEVA columns. The decontamination factors of more than 4 × 10(4) and 1 × 10(5) are achieved for molybdenum and ruthenium, respectively. Chemical yields of technetium in entire procedure range from 60% to 95% depending on the type and amount of samples, and the detection limit of 0.15 mBq/g for (99)Tc was obtained. The method has been successfully applied for the determination of (99)Tc in environmental solid samples.

An evaluation of a single-step extraction chromatography separation method for Sm–Nd isotope analysis of micro-samples of silicate rocks by high-sensitivity thermal ionization mass spectrometry

A single-step separation scheme is presented for Sm–Nd radiogenic isotope system on very small samples (1–3 mg) of silicate rock. This method is based on Eichrom ® LN Spec chromatographic material and affords a straightforward separation of Sm–Nd from complex matrix with good purity and satisfactory blank levels, suitable for thermal ionization mass spectrometry (TIMS). This technique, characterized by high efficiency (single-step Sm–Nd separation) and high sensitivity (TIMS on NdO + ion beam), is able to process rapidly (3–4 h), with low procedure blanks (<10 pg) and very small sample (1–3 mg). Replicate measurements by TIMS on 143Nd/ 144Nd ratios and Sm–Nd concentrations are presented for eleven international silicate rock reference materials, spanning a wide range of Sm–Nd contents and bulk compositions. The analytical results show a good agreement with recommended values within ±0.004% for the 143Nd/ 144Nd isotopic ratio and ±2% for Sm–Nd quantification at the 95% confidence level. It is noted that the uncertainty of this method is about 3 times larger than typical precision achievable with two-stage full separation followed by state-of-the-art conventional TIMS using Nd + ion beams which require much larger amounts of Nd. Hence, our single-step separation followed by NdO + ion beam technique is preferred to the analysis for microsamples.

SIMULTANEOUS DETERMINATION OF 14 QUINOLONES IN ROYAL JELLY BY LIQUID CHROMATOGRAPHY-TANDEM MASS SPECTROMETRY USING ANION-EXCHANGE SOLID-PHASE EXTRACTION

A new method based on liquid chromatography-tandem mass spectrometry has been developed for simultaneous determination of 14 quinolones (QNs) residues, including ciprofloxacin, danofloxacin, difloxacin, enoxacin, enrofloxacin, flumequine, lomefloxacin, marbofloxacin, norfloxacin, orbifloxacin, ofloxacin, pipemidic acid, pefloxacin, and sarafloxacin in royal jelly. The proposed analytical procedure involves extraction of the QNs from samples by 0.1 M sodium hydroxide aqueous solution, a step for clean-up and preconcentration of the analytes by anion-exchange solid-phase extraction (SPE) and liquid chromatographic separation with mass spectrometric detection. Internal standard calibration was applied with norfloxacin-D5 as internal standard (I.S.). Satisfactory recovery (from 64% to 113%), excellent repeatability precision (relative standard deviations, RSDs below 6%), reproducibility precision (RSDs below 10%), and low limits of quantifications (LOQs from 0.3 to 2.5 µg kg−1) were evaluated from spiked royal jelly samples at 2.5, 5.0, and 10.0 µg kg−1 three concentration levels. This protocol has been validated by five authoritative laboratories and successfully used for analysis of a large number of import–export samples (n > 2000). Norfloxacin and ciprofloxacin were found to be the most common contamination in royal jelly in the ranges of 3.5–30 µg kg−1 and 4.5–20 µg kg−1, respectively.

Combined cation-exchange and extraction chromatographic method of pre-concentration and concomitant separation of Cu(II) with high molecular mass liquid cation exchanger after its online detection

A selective method has been developed for the extraction chromatographic trace level separation of Cu(II) with Versatic 10 (liquid cation exchanger) coated on silanised silica gel (SSG-V10). Cu(II) has been extracted from 0.1 M acetate buffer at the range of pH 4.0–5.5. The effects of foreign ions, pH, flow-rate, stripping agents on extraction and elution have been investigated. Exchange capacity of the prepared exchanger at different temperatures with respect to Cu(II) has been determined. The extraction equilibrium constant ( K ex) and different standard thermodynamic parameters have also been calculated by temperature variation method. Positive value of Δ H (7.98 kJ mol −1) and Δ S (0.1916 kJ mol −1) and negative value of Δ G (−49.16 kJ mol −1) indicated that the process was endothermic, entropy gaining and spontaneous. Preconcentration factor was optimized at 74.7 ± 0.2 and the desorption constants K desorption 1(1.4 × 10 −2) and K desorption 2(9.8 × 10 −2) were determined. The effect of pH on R f values in ion exchange paper chromatography has been investigated. In order to investigate the sorption isotherm, two equilibrium models, the Freundlich and Langmuir isotherms, were analyzed. Cu(II) has been separated from synthetic binary and multi-component mixtures containing various metal ions associated with it in ores and alloy samples. The method effectively permits sequential separation of Cu(II) from synthetic quaternary mixture containing its congeners Bi(III), Sn(II), Hg(II) and Cu(II), Cd(II), Pb(II) of same analytical group. The method was found effective for the selective detection, removal and recovery of Cu(II) from industrial waste and standard alloy samples following its preconcentration on the column. A plausible mechanism for the extraction of Cu(II) has been suggested.

Extraction Chromatography Experiments on Repeated Operation using Engineering Scale Column System

Abstract The extraction chromatography separation experiments with the engineering scale column were carried out on a simulated waste solution. Ten times repeated separation experiments with two steps flow sheet using the CMPO/SiO2-P and the HDEHP/SiO2-P adsorbents provided durability of the adsorbents. The chromatograms obtained from the CMPO/SiO2-P column showed reproduced profiles through the multi-cycle operations. On the other hand, the time of development and peak shapes of the representative elements for HDEHP/SiO2-P column became slower and broader with the number of repeating the procedure due to leaching of HDEHP from the adsorbents.

Combined cation-exchange and extraction chromatographic method of preconcentration and concomitant separation of bismuth(III) with high molecular mass liquid cation exchanger

A selective method has been developed for the extraction chromatographic separation of Bi III with Versatic 10 coated on silanized silica gel (SSG). Bi III has been quantitatively extracted from 0.1 M acetate buffer at the range of pH 5.0–5.5. The result showed that the solution pH, influent volume, flow-rate and solution temperature would affect the sorption of Bi III. The sorbed Bi III was eluted with 0.1 M H 2SO 4. The extractor system has got good values of exchange capacity (1.42 meq. of H + g −1 of dry exchanger at 25 °C), break-through capacity (19.75 mg g −1 at pH 5.5) and column efficiencies (300) with respect to Bi III. The positive value of Δ H (12.63 kJ mol −1) and Δ S (0.271 kJ mol −1 K −1) and negative value of Δ G (−68.241 kJ mol −1) indicated that the sorption process was endothermic, entropy gaining and spontaneous in nature. P.F. has been optimized at 76.4 ± 0.3 and the desorption constants K desorption (8 × 10 −3) and K ′ desorption (1.4 × 10 −1) have been determined. R f values and selectivity factors for diverse metal ions with respect to that of Bi III have been determined by ion-exchange paper chromatography. Bi III has been separated from synthetic mixtures containing its congeners and other metal ions associated with it in ores and alloy samples. The method was found effective for removal of Bi III from different water samples. A plausible mechanism for the extraction of Bi III has been suggested.

An emergency urine bioassay method for 241Am by extraction chromatography and liquid scintillation counting

An emergency urine bioassay method has been developed for the determination of (241)Am in human urine samples. The method is based on extraction chromatographic separation of (241)Am from urine on a single DGA (N,N,N',N'-tetraoctyldiglycolamide) resin column followed by liquid scintillation counting of (241)Am. The minimum detectable activity (MDA) for the method was 0.02 Bq. Considering the volume of urine sample (17.2 ml) used by the method; the MDA was 1.3 Bq l(-1). Measurement accuracy (relative bias, B(r)) and repeatability (relative precision, S(B)) of the method were found to be -3.4 and 8.9 %, respectively, when urine samples were spiked with (241)Am (20 Bq l(-1)). Excellent linearity (r(2) > 0.999) was established over the range of 2-200 Bq l(-1). The method was also found to be robust (S(B)=10.2 %) against matrix effects from different urine samples. Performance of the rapid bioassay method for accuracy and repeatability were evaluated against the performance criteria for radiobioassay (ANSI N13.30) and found to be in compliance. Considering the simplicity, excellent analytical figures of merit and fast sample turnaround time (<1 h), it is a very promising rapid bioassay method for supporting the medical response to an emergency where internal contamination of (241)Am is involved.

Rapid and simultaneous determination of neptunium and plutonium isotopes in environmental samples by extraction chromatography using sequential injection analysis and ICP-MS

This paper reports an automated analytical method for rapid and simultaneous determination of plutonium isotopes (239Pu and 240Pu) and neptunium (237Np) in environmental samples. An extraction chromatographic column packed with TrisKem TEVA® resin was incorporated in a sequential injection (SI) system for the isolation of plutonium and neptunium from matrix elements and interfering nuclides. Valence adjustment is a crucial step to ensure the same chemical behavior of plutonium and neptunium onto the TEVA column and consequently to accomplish their simultaneous separation and detection. Distinct procedures were investigated and compared for the adjustment of oxidation states of plutonium and neptunium to Pu(IV) and Np(IV), respectively. A two-step protocol using sulfite and concentrated nitric acid as redox reagents was proven to be the most effective method. The analytical results for both plutonium and neptunium in three reference materials were in agreement with the recommended or literature values at the 0.05 significance level. The developed method is suitable for the analysis of up to 10 g of soil and 20 g of seaweed samples. The extraction chromatographic separation within the SI system for a single sample takes less than 1.5 h. As compared to batchwise procedures, the developed method significantly improves the analysis efficiency, reduces the labor intensity and expedites the simultaneous determination of plutonium and neptunium as demanded in emergency actions.

Reversed phase extraction chromatographic separation of ruthenium(III)

A new an innovative separation method has been developed using N-n-octylaniline (liquid anion exchanger) coated on silica gel. Ruthenium(III) has been extracted quantitatively from 0.05M hydrochloric acid, striped with aqueous solution of various acids and then determined by spectrophotometric method. Mutual separation scheme for ruthenium(III), iridium(III) and osmium(VIII) has been developed. Ruthenium(III) has been separated from commonly associated elements. Different parameter are studied viz effect of acid concentration, reagent concentration, striping agent, flow rate, foreign ion and synthetic mixture corresponding to alloys. Validity of method has been verified by separation of ruthenium(III) from fissium alloy.

Extraction chromatographic method of preconcentration and separation of lead (II) with high molecular mass liquid cation exchanger

A selective method has been developed for the extraction chromatographic separation of lead (II) with Versatic 911 (liquid cation exchanger) coated on silanised silica gel. Lead (II) has been extracted from 0.1 M acetate buffer at the range of pH 4.5–6.5. The effects of pH, flow-rate, stripping agents on extraction and elution have been investigated. Exchange capacity of the prepared exchanger at different temperatures with respect to lead (II) has been determined. The extraction equilibrium constant ( K ex) and different standard thermodynamic parameters have also been calculated by temperature variation method. The effect of pH on R f values in ion exchange paper chromatography has been investigated. In order to investigate the sorption isotherm, two equilibrium models, the Freundlich and Langmuir isotherms, were analyzed. Lead (II) has been separated from synthetic binary and multi-component mixtures containing various metal ions associated with it in ores and alloy samples. The method effectively permits sequential separation of lead (II) from synthetic quaternary mixture containing its congeners Cu (II), Sn (II), Hg (II) and Cu (II), Cd (II), Bi (III) of the same analytical group. The method was found effective for removal and recovery of lead (II) from industrial waste and standard alloy samples following its preconcentration on the column. A plausible mechanism for the extraction of lead (II) has been suggested.

Determination of rare-earth elements in uranium-bearing materials by inductively coupled plasma mass spectrometry

A novel and simple analytical procedure has been developed for the trace-level determination of lanthanides (rare-earth elements) in uranium-bearing materials by inductively coupled plasma sector-field mass spectrometry (ICP-SFMS). The method involves a selective extraction chromatographic separation of lanthanides using TRU resin followed by ICP-SFMS analysis. The limits of detection of the method proposed is in the low pg g(-1) range, which are approximately two orders of magnitude better than that of without chemical separation. The method was validated by the measurement of reference material and applied for the analysis of uranium ore concentrates (yellow cakes) for nuclear forensic purposes, as a potential application of the methodology.