scholarly journals Aspects on radiolabeling of 177Lu-DOTA-TATE: After C18 purification re-addition of ascorbic acid is required to maintain radiochemical purity

2014 ◽  
Vol 1 (1) ◽  
pp. 5 ◽  
Author(s):  
Stephan Maus ◽  
Erik De Blois ◽  
Stephan J. Ament ◽  
Mathias Schreckenberger ◽  
Wouter A. P. Breeman
Keyword(s):  
Ascorbic Acid ◽  
Solid Phase Extraction ◽  
Radiochemical Purity ◽  
Solid Phase ◽  
Phase Extraction ◽  
Injection Solution ◽  
Gentisic Acid ◽  
Radiolabeled Peptides ◽  
The Impact ◽  
Spe Purification

Purpose: Radiolabeled peptides like 177Lu-DOTA-TATE are vulnerable to radiolysis, which results in decreasedradiochemical purity (RCP) of these radiopeptides. Gentisic acid (GA) and ascorbic acid (AA) are well known ingredientsto reduce the effects of radiolysis. Currently, there is a trend to change the procedure from a manual to a cassette-basedautomated labeling and to introduce a C18 solid phase extraction (SPE) post-radiolabeling in order to removenon-incorporated 177Lu from the injection solution. However, with the introduction of SPE purification, GA and AAmight effectively be removed from injection solution with a concordant dramatically drop of the RCP. Therefore weinvestigated the impact of tC18 SPE purification on the RCP of 177Lu-DOTA-TATE.Methods: We compared the manual radiolabeling procedure with the cassette-based automated radiolabeling procedurewith/out tC18 SPE purification cartridge. The effect of tC18 purification on RCP of 177Lu-DOTA-TATE wasinvestigated by HPLC as function of the post-radiolabeling time and the concentration of activity.Results: After tC18 SPE purification, GA and AA were effectively removed and resulted in volume-dependent decreasein RCP, e.g. <95% after 5h in 20 mL. Re-addition of AA directly after tC18 SPE purification resulted in a RCP ≥95% at72h. In addition, with the cassette-based automated radiolabeling procedure we also found 28% of the original activityremaining in the activity-containing vial and tubing vs. < 1% with the manual procedure.Conclusion: Re-addition of AA post tC18 SPE purification is required to maintain RCP of 177Lu-DOTA-TATE.

scholarly journals A Purification Method of 18F-FP-(+)-DTBZ via Solid-Phase Extraction With Combined Cartridges

2021 ◽  
Vol 8 ◽  
Author(s):  
Yuyin Dai ◽  
Ri Sa ◽  
Feng Guan ◽  
Qi Wang ◽  
Yinghua Li ◽  
...  
Keyword(s):  
Solid Phase Extraction ◽  
Healthy Volunteers ◽  
Radiochemical Purity ◽  
Solid Phase ◽  
High Yield ◽  
Phase Extraction ◽  
Purification Method ◽  
Synthesis Time ◽  
Combined Use ◽  
Spe Purification

Background: To optimize [18F] 9-fluoropropyl-(+)-dihydrotetrabenazine (18F-FP-(+)-DTBZ) purification via solid-phase extraction (SPE) with combined cartridges to facilitate its widespread clinical application.Methods: A modified SPE purification method, employing Sep-Pak PS-2 and Sep-Pak C18 cartridges, was used for the preparation of 18F-FP-(+)-DTBZ. This method was compared to the purification method of high-pressure liquid chromatography (HPLC) and SPE with one cartridge, following quality control test and positron emission tomography (PET) imaging in healthy volunteers and patients with parkinsn's disease (PD).Results: A SPE purification method integrating Sep-Pak PS-2 and Sep-Pak C18 cartridges was implemented successfully. The retention time of 18F-FP-(+)-DTBZ purified by HPLC, SPE with Sep-Pak PS-2, SPE with Sep-Pak C18, and SPE with combined use of Sep-Pak PS-2 and Sep-Pak C18 cartridges was 8.7, 8.8, 8.7, and 8.9 min, respectively. Fewest impurity peak was detected in 18F-FP-(+)-DTBZ purified by the SPE with combined use of Sep-Pak PS-2 and Sep-Pak C18 cartridges. This modified SPE purification method provided a satisfactory radiochemical yield of 29 ± 1.8% with radiochemical purity &gt;99% and shortened synthesis time to 27 min. The brain uptake of 18F-FP-(+)-DTBZ purified by the modified SPE was comparable to that purified by HPLC in both healthy volunteers and PD patients.Conclusions: A SPE method integrating Sep-Pak PS-2 and Sep-Pak C18 cartridges for purification of 18F-FP-(+)-DTBZ may be highly suited to automatic synthesis for routine clinical applications, as it provides excellent radiochemical purity, high yield as well as operational simplicity.

A solid-phase extraction method that eliminates matrix effects of complex pulp mill effluents for the analysis of lipophilic wood extractives

2020 ◽  
Vol 35 (4) ◽  
pp. 577-588
Author(s):  
Sebastian España Orozco ◽  
Philipp Zeitlinger ◽  
Karin Fackler ◽  
Robert H. Bischof ◽  
Antje Potthast
Keyword(s):  
Solid Phase Extraction ◽  
Matrix Effects ◽  
Solid Phase ◽  
Internal Standard ◽  
Pulp Mill ◽  
Phase Extraction ◽  
Wood Extractives ◽  
Wood Extractive ◽  
Pulp Mill Effluents ◽  
The Impact

AbstractThe extraction of lipophilic wood extractives from pulp and paper process waters proves to be a challenging task, due to harsh and alternating process and sample conditions. This study has determined the potential use of polymeric sorbents for solid-phase extraction (SPE) and compared to classical silica-based reversed-phase packed columns, with polymeric hydrophilic-lipophilic balanced (HLB) cartridges being the sorbent with the most potential. Recovery functions were obtained with an internal standard mixture representative for the main lipophilic wood extractive groups, which are fatty acids and alcohols, sterols, sterol esters and triglycerides. The impact of pH, sample volume and sample matrix, expressed as TOC and cations, on the retention behavior of lipophilic extractives during SPE of industrial samples were determined with polymeric HLB sorbent. High variations in the composition of pulp mill matrices led to different optimal extraction conditions. Thus, a new SPE protocol was developed, which bypasses matrix interferences and omits the loss of analytes due to sample preparation. The method is applicable to different pulp mill effluents with large discrepancies in pH and sample matrices, resulting in recoveries >90 % with RSD <5 % for all lipophilic wood extractives.

scholarly journals Solid-Phase Extraction Embedded Dialysis (SPEED), an Innovative Procedure for the Investigation of Microbial Specialized Metabolites

Marine Drugs ◽  
2021 ◽  
Vol 19 (7) ◽  
pp. 371
Author(s):  
Phuong-Y Mai ◽  
Géraldine Le Goff ◽  
Erwan Poupon ◽  
Philippe Lopes ◽  
Xavier Moppert ◽  
...  
Keyword(s):  
Solid Phase Extraction ◽  
Solid Phase ◽  
Chemical Space ◽  
Molecular Profile ◽  
Phase Extraction ◽  
Specialized Metabolites ◽  
Streptomyces Albidoflavus ◽  
Cultivation Process ◽  
The Impact

Solid-phase extraction embedded dialysis (SPEED technology) is an innovative procedure developed to physically separate in-situ, during the cultivation, the mycelium of filament forming microorganisms, such as actinomycetes and fungi, and the XAD-16 resin used to trap the secreted specialized metabolites. SPEED consists of an external nylon cloth and an internal dialysis tube containing the XAD resin. The dialysis barrier selects the molecular weight of the trapped compounds, and prevents the aggregation of biomass or macromolecules on the XAD beads. The external nylon promotes the formation of a microbial biofilm, making SPEED a biofilm supported cultivation process. SPEED technology was applied to the marine Streptomyces albidoflavus 19-S21, isolated from a core of a submerged Kopara sampled at 20 m from the border of a saltwater pond. The chemical space of this strain was investigated effectively using a dereplication strategy based on molecular networking and in-depth chemical analysis. The results highlight the impact of culture support on the molecular profile of Streptomyces albidoflavus 19-S21 secondary metabolites.

scholarly journals One-Step Synthesis of N-Succinimidyl-4-[18F]Fluorobenzoate ([18F]SFB)

Molecules ◽  
2019 ◽  
Vol 24 (19) ◽  
pp. 3436 ◽  
Author(s):  
Ida Nymann Petersen ◽  
Jacob Madsen ◽  
Christian Bernard Matthijs Poulie ◽  
Andreas Kjær ◽  
Matthias Manfred Herth
Keyword(s):  
Solid Phase Extraction ◽  
Total Synthesis ◽  
Radiochemical Purity ◽  
Solid Phase ◽  
Phase Extraction ◽  
One Pot ◽  
Synthesis Time ◽  
Synthesis Route ◽  
One Step

Herein, we present a one-step labeling procedure of N-succinimidyl-4-[18F]-fluorobenzoate ([18F]SFB) starting from spirocyclic iodonium ylide precursors. Precursor syntheses succeeded via a simple one-pot, two-step synthesis sequence, in yields of approximately 25%. Subsequent 18F-nucleophilic aromatic labeling was performed, and radiochemical incorporations (RCCs) from 5–35% were observed. Purification could be carried out using HPLC and subsequent solid phase extraction. Radiochemical purity (RCP) of >95% was determined. The total synthesis time, including purification and formulation, was no longer than 60 min. In comparison to the established 3-step synthesis route of [18F]SFB, this one-step approach avoids formation of volatile radioactive side-products and simplifies automatization.

scholarly journals Solid-Phase Extraction Cleanup for Determining Ascorbic Acid and Dehydroascorbic Acid by Titration with 2,6-Dichlorophenolindophenol

1996 ◽  
Vol 79 (5) ◽  
pp. 1236-1243 ◽  
Author(s):  
Krishna K Verma ◽  
Archana Jain ◽  
Bhushan Sahasrabuddhey ◽  
Kalpana Gupta ◽  
Sanjeev Mishra
Keyword(s):  
Ascorbic Acid ◽  
Solid Phase Extraction ◽  
Solid Phase ◽  
Dehydroascorbic Acid ◽  
Original Method ◽  
Phase Extraction ◽  
Fruit And Vegetable Juices ◽  
Coloring Matter ◽  
Sulfhydryl Compounds

Abstract Ascorbic acid is frequently determined by titration with 2,6-dichlorophenolindophenol. The determination is rapid, but the method is neither specific for ascorbic acid nor very sensitive. The coloring matter in the assay solution interferes with the visual endpoint, and iron(ll), copper(l), sulfite, and sulfhydryl substances such as cysteine and glutathione interfere with the color reaction. Sample cleanup by solid-phase extraction with C18 bonded silica was developed to remove the coloring matter. Extraction sorbent impregnated with 2,2′-bipyridyl, 2,9-dimethyl-1,10-phenanthroline (neocuproine) and Jv-ethylmaleimide removes Fe(ll), Cu(l), and sulfhydryl compounds, respectively. The procedure was applied to highly colored multivitamin pharmaceuticals, soft drinks, and fruit and vegetable juices. In contrast to the results from the original method, which is not applicable to such samples, the results obtained by the method incorporating cleanup were accurate and selective for ascorbic acid. The sample cleanup also permitted determination of dehydroascorbic acid by reducing it to ascorbic acid with cysteine and titrating the ascorbic acid formed with indophenol. As little as 3 μg ascorbic acid was determined by the method incorporating cleanup.

scholarly journals Application of Magnetic Nanoparticles Coated with Crosslinked Zwitterionic Poly(ionic liquid)s for the Extraction of Oligonucleotides

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3146
Author(s):  
Łukasz Nuckowski ◽  
Krzysztof Dzieszkowski ◽  
Zbigniew Rafiński ◽  
Sylwia Studzińska
Keyword(s):  
Ionic Liquid ◽  
Magnetic Nanoparticles ◽  
Solid Phase Extraction ◽  
Ammonium Acetate ◽  
Solid Phase ◽  
Extraction Procedure ◽  
Phase Extraction ◽  
Dispersive Solid Phase Extraction ◽  
Poly Ionic Liquid ◽  
The Impact

Magnetic nanoparticles coated with zwitterionic poly(ionic liquid)s were applied for dispersive solid-phase extraction of oligonucleotides. The materials were synthesized by miniemulsion copolymerization of ionic liquids and divinylbenzene on magnetic nanoparticles. The functional monomers contain a positively charged imidazolium ring and one of the anionic groups: derivatives of acetate, malonate, or butyl sulfonate ions. Adsorption of unmodified DNA oligonucleotide on obtained materials was possible in ion-exchange (IE) and hydrophilic interactions (HI) mode. The adsorption in IE was possible at low pH and was almost complete. The adsorption in HI mode required the usage of appropriate addition of organic solvent but did not provide full adsorption. Studies on the desorption of the analytes included determining the impact of ammonium acetate concentration and pH and organic solvents addition on the recovery. The material containing acetic fragments as an anionic group was selected for the final procedure with the use of 10 mM ammonium acetate (pH = 9.5)/methanol (50/50, v/v) as an elution solution. The magnetic dispersive solid-phase extraction procedure was tested for the oligonucleotides with various modifications and lengths. Moreover, it was applied to extract DNA oligonucleotide and its synthetic metabolites from enriched human plasma without any pre-purification, with recoveries greater than 80%.

scholarly journals Evolution of Environmentally Friendly Strategies for Metal Extraction

Separations ◽  
2020 ◽  
Vol 7 (1) ◽  
pp. 4 ◽  
Author(s):  
Govind Sharma Shyam Sunder ◽  
Sandhya Adhikari ◽  
Ahmad Rohanifar ◽  
Abiral Poudel ◽  
Jon R. Kirchhoff
Keyword(s):  
Solid Phase Extraction ◽  
Solid Phase ◽  
Environmentally Friendly ◽  
Metal Extraction ◽  
Phase Extraction ◽  
Aquatic Life ◽  
Valuable Metals ◽  
Recent Developments ◽  
Sorbent Materials ◽  
The Impact

The demand for the recovery of valuable metals and the need to understand the impact of heavy metals in the environment on human and aquatic life has led to the development of new methods for the extraction, recovery, and analysis of metal ions. With special emphasis on environmentally friendly approaches, efforts have been made to consider strategies that minimize the use of organic solvents, apply micromethodology, limit waste, reduce costs, are safe, and utilize benign or reusable materials. This review discusses recent developments in liquid- and solid-phase extraction techniques. Liquid-based methods include advances in the application of aqueous two- and three-phase systems, liquid membranes, and cloud point extraction. Recent progress in exploiting new sorbent materials for solid-phase extraction (SPE), solid-phase microextraction (SPME), and bulk extractions will also be discussed.

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