Solid-phase Extraction Resins Research Articles

Characterization of dissolved organic matter from a Greenland ice core by nanospray ionization Fourier transform ion cyclotron resonance mass spectrometry

AbstractNanospray ionization Fourier transform ion cyclotron resonance mass spectrometry was developed as a tool for examining the dissolved organic matter (DOM) present in ice cores, significantly reducing the sample volume required for extraction compared with previous studies. Using smaller sample volumes is important for resolving temporal changes in ice-core DOM. We demonstrate that a small volume of ice-core meltwater can be extracted and analyzed with sufficient mass spectral sensitivity to describe the molecular composition of the DOM. Two different solid-phase extraction resins (PPL and C18) were compared to examine potential fractionation of the DOM. Over 2500 unique molecular formulas isolated from two different Greenland ice-core samples, dated to approximately AD 1660 and AD 1360, were obtained from the analyses. Method and sensitivity improvements provide an opportunity for organic matter characterization at higher temporal resolution than our previous analyses afforded and allows for examination of ice cores containing low levels of organic carbon.

Radiometals from liquid targets: 94mTc production using a standard water target on a 13 MeV cyclotron

Solutions containing a high concentration (0.325–0.995g/ml) of natural-abundance ammonium heptamolybdate tetrahydrate ((NH4)6Mo7O24)·4H2O were irradiated at 13MeV on a proton-beam cyclotron using a standard liquid target. 94mTc was produced via the 94Mo(p,n)94mTc reaction with measured yields of 110±20MBq for the highest concentrated solution using 5μA proton beams for 60min. Saturation yields of up to 40±6MBq/μA were achieved. Pertechnetate was isolated from the target mixture with 70.9±0.7% efficiency using a solid-phase extraction resin.

Multiple functions of a multi‐component mating pheromone in sea lamprey Petromyzon marinus

The role of the C24 sulphate in the mating pheromone component, 7α,12α,24-trihydroxy-5α-cholan-3-one 24-sulphate (3kPZS), to specifically induce upstream movement in ovulated female sea lampreys Petromyzon marinus was investigated. 7α,12α-dihydroxy-5α-cholan-3-one 24-oic acid (3kACA), a structurally similar bile acid released by spermiated males, but lacking the C24 sulphate ester, was tested in bioassays at concentrations between 10(-11) and 10(-14) molar (M). 3kACA did not induce upstream movement in females or additional reproductive behaviours. In contrast, spermiated male washings induced upstream movement, prolonged retention on a nest and induced an array of nesting behaviours. Differential extraction and elution by solid-phase extraction resins showed that components other than 3kPZS + 3kACA are necessary to retain females on nests and induce nest cleaning behaviours. All pheromone components, including components in addition to 3kPZS + 3kACA that retain females and induce nest cleaning behaviours were released from the anterior region of the males, as had been reported for 3kPZS. It is concluded that the sea lamprey male mating pheromone has multiple functions and is composed of multiple components.

A new method research for determination of natural pigment crocin yellow in foods by solid-phase extraction ultrahigh pressure liquid chromatography

Crocin yellow was determined in soft drinks, sausages and sauces by ultra performance liquid chromatography coupled with ultraviolet detector and analyzed within 5 min using a short analytical column ACQUITY UPLC HSS T3 2.1 × 100 mm 1.8 μm) with gradient elution. An innovative pretreatment method based on homemade macroporous resin solid-phase extraction (SPE) column was established. The SPE column packed with macroporous resins could simplify the sample preparation of multi-matrices and be reused by regeneration steps. The recoveries of crocin yellow added to soft drinks, sausages and sauces at three levels ranged from 81.3% to 106.2%, and relative standard deviations (RSDs) were within 8.8%. The limits of quantitation of soft drinks, sausages and sauces were 0.5 mg/kg, 5 mg/kg and 5 mg/kg, respectively.

Characterization and application of SuperLig® 620 solid phase extraction resin for automated process monitoring of 90Sr

Characterization of SuperLig® 620 solid phase extraction resin was performed in order to develop an automated on-line process monitor for 90Sr. The main focus was on strontium separation from barium, with the goal of developing an automated separation process for 90Sr in high-level wastes. High-level waste contains significant 137Cs activity, of which 137mBa is of great concern as an interference to the quantification of strontium. In addition barium, yttrium and plutonium were studied as potential interferences to strontium uptake and detection. A number of complexants were studied in a series of batch Kd experiments, as SuperLig® 620 was not previously known to elute strontium in typical mineral acids. The optimal separation was found using a 2 M nitric acid load solution with a strontium elution step of ~0.49 M ammonium citrate and a barium elution step of ~1.8 M ammonium citrate. 90Sr quantification of Hanford high-level tank waste was performed on a sequential injection analysis microfluidics system coupled to a flow-cell detector. The results of the on-line procedure are compared to standard radiochemical techniques in this paper.

New SPE column packing material: Retention assessment method and its application for the radionuclide chromatographic separation

The preparation of the OASIS®-HLB sorbent based solid phase extraction (SPE) resins and their application for the 177Lu radioisotope separation were investigated. Di-(2-ethylhexyl) orthophosphoric acid (HDEHP) impregnated OASIS-HLB sorbent based SPE resins (OASIS-HDEHP) were successfully developed from this investigation. The wettable porosity structure of the moderately extractant impregnated OASIS-HDEHP resins is favorable for the effective diffusion of polar and ionic solutes giving good separation performance. Its good wetting ability offers ease of packing into conventional chromatographic columns. Their off-gassing-free operation makes OASIS-HDEHP columns good for long term use with highly consistent elution dynamics (several dozens of separations perfectly achievable on the same column). The simple method for the capacity factor (k’) evaluation was developed to facilitate the characterization of the SPE chromatographic resin column. A competent procedure using OASIS-E30RS resin (one member of the OASIS-HDEHP resin group) for the separation of no-carrier added (n.c.a) 177Lu from the bulk amount of Yb target was developed. This separation procedure has showed very good performance with several prominent advantages such as the much shorter separation time (5–6 hours) and high reproducibility. Its high adsorption capacity for Yb and Lu makes it ideal for the separation of the bulky sample (50 mg Yb target for the 20 g weight resin column) for the production of the several Ci of 177Lu radioactivity.

Alternative chromatographic processes for no-carrier added 177Lu radioisotope separation

The conventional multi-column solid phase extraction (SPE) chromatography technique using di-(2-ethylhexyl)orthophosphoric acid (HDEHP) impregnated OASIS-HLB sorbent based SPE resins (OASIS-HDEHP) was developed for the separation of no-carrier added (n.c.a) 177 Lu from the bulk quantity of ytterbium target. This technique exploited the large variation of lutetium metal ion distribution coefficients in the varying acidity of the HCl solution–OASIS-HDEHP resin systems for the consecutive loading-eluting cycles performed on different columns. The production batches of several hundred mCi n.c.a 177 Lu radioisotope separated from 50 mg Yb target activated in a nuclear reactor of medium neutron flux (Φ = 5 . 10 13 n . cm –2. s –1 ) were successfully performed using the above mentioned separation technique. With the target irradiation in a reactor of thermal neutron flux Φ = 2 . 10 14 n . cm –2. s –1 or the parallel run of several separation units , many Ci-s of n.c.a 177 Lu can be profitably produced. The OASIS-HDEHP resin based multi-column SPE chromatography technique makes the separation process simple and economic and offers an automation capability for operation in highly radioactive hazardous environments.

Alternative chromatographic processes for no-carrier added 177Lu radioisotope separation

HPLC technique combined with the simple conventional column solid phase extraction (SPE) chromatography using di-(2ethylhexyl)orthophosphoric acid (HDEHP) impregnated OASIS-HLB sorbent based SPE resins (OASIS-HDEHP ) was developed for the separation of no-carrier added (n.c.a) 177 Lu from the bulk quantity of ytterbium target. This combination strategy was based on combining the advantages of the better resolution of HPLC separation of n.c.a 177 Lu from the few milligram level Yb target with the high capacity of the OASIS-HDEHP column for the separation of 177 Lu from the bulk Yb target. The production batches of several hundred mCi activity of n.c.a 177 Lu radioisotope separated from 50 mg Yb target activated in a nuclear reactor of medium neutron flux (Φ = 5·10 13 n·cm -2 ·s -1 ) were successfully performed using this combined separation technique. With the target irradiation in a reactor of higher thermal neutron flux or with the parallel run of several separation units, several Ci-s of n.c.a 177 Lu can be profitably produced on a commercial production basis.

Assessment of contaminant lability during phytoremediation of polycyclic aromatic hydrocarbon impacted soil

Polycyclic aromatic hydrocarbons (PAHs) are recalcitrant compounds, some of which are known carcinogens, often found in high residual soil concentrations at industrial sites. Recent research has confirmed that phytoremediation holds promise as a low-cost treatment method for PAH contaminated soil. In this study, the lability of soil bound PAHs in the rhizosphere was estimated using solid phase extraction resin. An extraction time of 14 days was determined to be appropriate for this study. Resin-extractable PAHs, which are assumed to be more bioavailable, decreased during plant treatments. Significant reductions in the labile concentrations of several PAH compounds occurred over 12 months of plant growth. The differences in concentration between the unplanted and the planted soil indicate that the presence of plant roots, in addition to the passage of time, contributes to reduction in the bioavailability of target PAHs.

Application of an Enzyme-Linked Immunosorbent Assay for the Analysis of Paraquat in Human-Exposure Samples

Paraquat is a toxic quaternary ammonium compound used as an herbicide around the world. Easy, fast, and inexpensive but sensitive methods are needed to study the effects of long-term, low-level exposure of paraquat on human health. An enzyme-linked immunosorbent assay (ELISA) was used for quantification of paraquat in urine and air-filter samples collected in a human-exposure study among farm workers in Costa Rica. A sample pretreatment consisted of removal of interfering substances using solid-phase extraction resin columns. The precision and accuracy of the method were tested using duplicate spiked urine samples. The correlation between results for blind samples obtained using ELISA and liquid chromatography-mass spectrometry was significant (R2 = 0.945 and 0.906 for spiked and field samples, respectively). With an LOQ of 2 ng mL(-1), this ELISA method was able to distinguish the exposed from the nonexposed farm workers. For the air-filter analysis, paraquat was extracted by 9 M H2SO4 at 60 degrees C for 12 hours, and the results obtained by ELISA showed good correlation (R2 = 0.918) with the spectrophotometric (256 nm) measurements. Paraquat in acid-stabilized urine samples was very stable, and no significant losses were detected during a 3-month storage at room temperature, at 4 degrees C, or at -20 degrees C.

Pressurized Liquid Extraction of Bioactive Compounds from Taiwan Pines

An experiment combining the Taguchi methodology with the response surface methodology to optimize the Pressurized Liquid Extraction (PLE) of proanthocyanidins from Taiwan pines was conducted. A L18 orthogonal array was selected to investigate the total yield and the amount of proanthocyanidins. Experimental results showed that the extraction temperature most significantly affected the efficiency of extraction, but that a higher temperature also caused decomposition of bioactive components. Optimum conditions were identified as 20% EtOH, 140℃,750 psig, and 1.5h. The PLE total yield, proanthocyanidins content and total flavonoids were 2.09, 2.07, and 2.01 times greater than those obtained using a 50% EtOH conventional extraction method. Hot pressurized extraction has the advantages of low energy and high yield of bioactive compounds. The antioxidant activities of several extracts from two Taiwan pine-needles were individually evaluated for scavenging of DPPH free radicals and superoxide anion radicals, and for the inhibition of lipid peroxidation. The results revealed that both PLE M (Pinus morrisonicola) and PLE T (Pinus taiwanensis) extracted from two fresh pine needles scavenged 78.91% of DPPH free radicals. Air-dried pine needles also strongly inhibited superoxide anion radicals. The purification of four anthocyanidins from a PLE T extract was initially tested using HP-20 resin solid phase extraction and showed little enhancement. The isolation, purification and antioxidative mechanism of active components from pine needles need to be further investigated.

Determination of Clopidol Residues in Chicken Tissues by Liquid Chromatography: Collaborative Study

Eighteen laboratories participated in a collaborative study on the determination of clopidol residues in chicken muscle tissues by liquid chromatography. Of these, results from 16 laboratories which rigorously followed the method were subjected to statistical analysis. The method performance was assessed by all participants using 14 samples of chicken muscle fortified at concentrations ranging from 0.1 to 5.0 mg/kg. In addition, 9 participants each reported results for 6 clopidol-incurred samples in chicken muscle. Test portions were extracted with acetonitrile, and the extracts were purified with alumina and anion exchange resin solid-phase extraction cartridges in sequence. Clopidol was separated by reversed-phase liquid chromatography and quantified at 270 nm. Average recoveries ranged from 81.8 to 85.4%, reproducibility relative standard deviation (RSDR) ranged from 11.9 to 22.6%, and repeatability relative standard deviation (RSDr) ranged from 9.9 to 15.1%. For clopidol-incurred samples at concentrations of 0.100-0.687 mg/kg, the mean determination value range was 0.099-0.659 mg/kg; RSDR was 12.6-19.8%, RSDr was 3.1-8.5%; and HORRAT values were 0.7-1.1. The accuracy and precision of the method are in conformity with the requirements specified by AOAC INTERNATIONAL. The method was adopted Official First Action in April 2003.

Determination of pu isotopes in seawater by an on-line sequential injection technique with sector field inductively coupled plasma mass spectrometry.

An on-line sequential injection (SI) system combined with sector field inductively coupled plasma mass spectrometry was developed for the determination of ultratrace level 239Pu and 240Pu in seawater. The potential of this method is the substantial reduction of a sample volume and rapidity in the determination of Pu isotopes. A chemical purification and preconcentration of Pu isotopes were accomplished by the on-line SI system with two microcolumns of solid-phase extraction resins, Sr-Spec and TEVA-Spec. The MCN-6000 microconcentric nebulizer was used as a sample introduction system because of low interference effect and good sample utilization. With this method, it was possible to analyze ultratrace levels of Pu isotopes in only 5 L of surface seawater with an analysis speed of 4 h/sample. The precision of the measurement for the 239Pu and 240Pu was less than 3.4 (n = 7) and 5% (n = 7) for 5 L of seawater. The detection limits for 239Pu and 240Pu were 0.64 (1.5 microBq/mL) and 0.19 fg/mL (1.6 microBq/mL), respectively. The accuracy of this method was verified by using the reference seawater (IAEA-381) as well as by the comparison with the a-spectrometry.

Speciation of aqueous chromium by use of solid-phase extractions in the field.

Here the fate and mobility of chromium in an organic-rich wetland area was studied through a field investigation in which chromium speciation in aqueous samples was estimated by use of solid-phase extraction resins that removed the cationic, anionic, and hydrophobic organic species from solution. Results show that aqueous chromium concentrations in the surface and pore waters at this site are higher than would be predicted by simple thermodynamic equilibrium with solid chromium hydroxides. Hexavalent chromium was not observed and therefore could not explain these higher than expected chromium concentrations. Aqueous chromium in concentrations greater than 30 microg/L was found to be slightly correlated with total dissolved organic carbon (R2 = 0.66), thus suggesting enhanced chromium concentrations because of complexation with organic ligands. The results of the solid-phase extraction performed show that aqueous chromium in the wetland pore water and surface water exists primarily as an anion (96%). It is concluded that the solubility and mobility of chromium are controlled, at least in part, by complexation with dissolved organic carbon and that this may be a thermodynamically controlled process.

Flow Injection Sample Pretreatment for Determination of Lead by Flame Atomic Absorption Spectrophotometry

Flow injection sample pretreatment for determination of lead by flame atomic absorption spectrophotometry has been developed. Utilizing an in-valve mini-column, packed with a solid phase extraction resin (Sr.spec), lead was preconncentrated and separated from the matrix. The conditions for sorption and desorption of lead were investigated. A 1 M nitric acid solution and 0.005 M EDTA solution of pH 7 were suitable for sorption and desorption step respectively. A concentration efficiency of 11 min was achieved. A linear calibration was obtained for 0.1-5.0 μg Pb and a single standard calibration can be applied. The method has been applied to the determination of lead in certified reference materials, leachates and digests of tin tailing samples. The system allows rapid analysis of very small sample volumes.

Method development for trace determination of poly(naphthalenesulfonate)-type pollutants in water by liquid chromatography–electrospray mass spectrometry

A very sensitive analytical procedure based on LC–MS for determining trace amounts of the more relevant poly(naphthalenesulfonate) (PNS) contaminants present in environmental waters is presented. Extraction was performed on a styrene–divinylbenzene copolymer resin solid-phase extraction cartridge after addition of ammonium acetate to the sample. Small amounts of ammonium acetate in the mobile phase allowed the determination and characterisation of the four shorter oligomers by liquid chromatography–electrospray mass spectrometry. Under such conditions the electrospray process generates fully ionised molecules which greatly simplifies interpretation of spectra and quantitation. Additionally, confirmatory ions can be generated by the in-source collision-induced decomposition process. The effectiveness of the method was assessed in recovery experiments from drinking and river water samples spiked with commercial mixtures of PNS concrete plasticizers also referred as naphthalenesulfonate–formaldehyde condensates. Moreover, the performance of this method was compared to methods using ion-pair chromatography coupled with fluorimetric and mass spectrometric detection. Method detection limits were in the low picomolar range (1 ng/l for the monomer) for each isomer. In order to evaluate the environmental relevance of PNS type compounds waste, river and ground water grab samples were analysed. Concentrations of PNS oligomers detected in these samples ranged between 53 ng/l and 32 μg/l.

A NOVEL SOLID-PHASE EXTRACTION SCHEME FOR THE GROUP SEPARATION OF HIGH FIELD STRENGTH ELEMENTS (Nb, Ta, Zr, Hf) FROM Al-, Ti-, AND Fe-RICH GEOLOGICAL MATERIALS

This paper reports a novel solid-phase extraction scheme for the group separation of high field strength elements (HFSE) Nb, Ta, Zr, and Hf from Ti-, Fe-, and Al-rich geological materials. The solid-phase extraction resin was prepared by impregnating hydrophobic microporous polymer beads with N-benzoyl-N-phenylhydroxylamine (BPHA) dissolved in chloroform followed by evaporating the solvent. Geological samples were attacked with concentrated hydrofluoric acid and treated with perchloric acid fuming to remove silica. The rock sample was then made up with 4 M HCl solution and loaded onto an extraction column packed with the solid-phase extraction resin. All the major rock constituents (Ca, Mg, K, Na, Al, Fe, Mn, and Ti) were eluted with 4 M hydrochloric acid followed by 2 M sulfuric acid containing 1% v/v H2O2. The HFSE were retained on the extraction column and subsequently eluted with 0.5 M oxalic-0.2 M hydrofluoric acid or 5 M hydrofluoric acid. The potentialities of the separation scheme are highlighted by the easy separation of HFSE from the rock matrix and Ti. The solid-phase extraction is superior to liquid-liquid extraction in analytical separations with respect to selectivity and manipulation.

ChemInform Abstract: Solid-Phase Extraction for Combinatorial Libraries

Solid-phase extraction (SPE) has during the last three years emerged as a convenient method for the purification of compound libraries prepared by solution synthesis. The widespread use of SPE in combinatorial chemistry can be explained by straightforward SPE method development facilitated by the availability of numerous commercial SPE resins. High-speed automated SPE is readily accomplished by taking advantage of commercial laboratory robot systems. The present review summarizes and discusses advancements made in the use of different SPE resins and molecule tagging techniques for optimization of ion-exchange, reversed-phase, normal-phase and fluorous-phase SPE in combinatorial chemistry.

Solid-phase extraction for combinatorial libraries

Solid-phase extraction (SPE) has during the last three years emerged as a convenient method for the purification of compound libraries prepared by solution synthesis. The widespread use of SPE in combinatorial chemistry can be explained by straightforward SPE method development facilitated by the availability of numerous commercial SPE resins. High-speed automated SPE is readily accomplished by taking advantage of commercial laboratory robot systems. The present review summarizes and discusses advancements made in the use of different SPE resins and molecule tagging techniques for optimization of ion-exchange, reversed-phase, normal-phase and fluorous-phase SPE in combinatorial chemistry.

Determination of99Tc in reactor loop decontamination liquid waste using extraction chromatography

A new analytical method has been developed to determine99Tc in samples of aqueous radioactive waste containing high levels of60Co (103–106 Bq/l) in mixed forms (simple cationic60Co2+ and coordinated complex forms). The method consists of selective extraction of the99Tc with a combination of cation exchange and solid-phase extraction resins under strong acid conditions. Quantification of the isolated99Tc is accomplished using liquid scintillation counting. The method provides high recoveries (>98%), is simpler than classical solvent extraction methods, eliminates the use of chlorinated organic solvents and the time of analysis is reduced by a factor of 2 when compared to solvent extraction methods.