Response surface methodology (RSM) was used to determine the optimal conditions for ultrasound-assisted extraction (UAE) of Notoginsenoside Fc (Fc) from panax notoginseng leaves. The experiment ...utilized a Box–Behnken design (BBD) and separation conditions were optimized. The optimum extraction conditions were as follows: extraction time = 1.5 h, ethanol concentration = 86%, liquid-to-solid ratio = 19:1. The experimentally obtained values were in accordance with the values predicted by the RSM model. We determined that the RSM model was able to successfully simulate the optimal extraction of Fc from the leaves. Further, Fc was enriched from Panax notoginseng through nine macroporous resins, and HPD-100 macroporous resins were selected for preliminary enrichment of Fc due to its economic costs and benefits. Subsequently, octadecyl silane (ODS) column chromatography was used to improve the purity of Fc to over 90% after separation by ODS column chromatography. Fc with a purity greater than 95% can be obtained by recrystallization. This is the first study that has focused on the extraction and enrichment of Fc from Panax notoginseng leaves using macroporous resin combined with ODS column chromatography, which provides the possibility for further application of Fc.
Diterpenoids are considered the major bioactive components in Scutellaria barbata to treat cancer and inflammation, but few comprehensive profiling studies of diterpenoids have been reported. Herein, ...a stepwise diagnostic product ions (DPIs) filtering strategy for efficient and targeted profiling of diterpenoids in Scutellaria barbata was developed using UHPLC-Q-Exactive-Orbitrap-MS. After UHPLC-HRMS/MS analysis of six diterpenoid reference standards, fragmentation behaviors of these references were studied to provide DPIs. Then, stepwise DPIs filtering aimed to reduce the potential interferences of matrix ions and achieve more chromatographic peaks was conducted to rapidly screen the diterpenoids. The results demonstrated that stepwise DPIs were capable of simplifying the workload in data post-processing and the effective acquisition of low abundance compounds. Subsequently, DPIs and MS/MS fragment patterns were adopted to identify the targeted diterpenoids. As a result, 381 diterpenoids were unambiguously or tentatively identified, while 141 of them with completely new molecular weights were potential new diterpenoids for Scutellaria barbata. These results demonstrate that the developed stepwise DPIs filtering method could be employed as an efficient, reliable, and valuable strategy to screen and identify the diterpenoid profile in Scutellaria barbata. This might accelerate and simplify target constituent profiling from traditional Chinese medicine (TCM) extracts.
This work is focused on the separation of a daughter radionuclide .sup.221Fr from medicinal .sup.225Ac to provide a source of pure .sup.221Fr fraction for other studies. To achieve such a goal, ...diglycolamide extraction agents were immobilized on polymer matrix and tested in extraction chromatography experiments. Particularly experiments with N,N,N',N'tetrakis2-ethylhexyldiglycolamide in nitric acid medium provided promising results and the material was further studied in column experiments. The chosen conditions of separation provided .sup.221Fr in yields over 65% with .sup.225Ac contamination under 1% in less than 5 min, which is a sufficient proof of concept suitable for further studies.
Supercritical fluid chromatography (SFC), which employs pressurized carbon dioxide as the major component of the mobile phase, has been known for several decades but has faced a significant ...resurgence of interest in the recent years, thanks to the development of modern instruments to comply with current expectations in terms of robustness and sensitivity. This review is focused on the recent literature, specifically since the introduction of modern systems but in relation to older literature, to identify the changing trends in application domains. Typically, natural products, bioanalysis, food science, and environmental analyses are all strongly increasing. Together with reduced extra-column volumes in the instruments, the advent of sub-2-μm particles and superficially porous particles in the stationary phases is favoring ultra-high-performance SFC (UHPSFC) allowing for improved resolution and faster analyses, but without the constraints of viscous liquids encountered in ultra-high-performance liquid chromatography (UHPLC). Hyphenation to mass spectrometry is also more frequent and opened the way to new application domains, and raises different issues from liquid chromatography mobile phases, especially due to decompression of carbon dioxide. It is also shown that the frontiers between SFC and HPLC are fading, as switching from one method to the other, even within the course of a single analysis, is facilitated my modern instruments. The present review is not intended to be exhaustive but rather giving a snapshot of recent trends in supercritical fluid chromatography, based on the observation of about 500 papers published in English-written peer-reviewed journals from 2014 to 2018.
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► Review of novel cyclodextrin chiral stationary phases (CD-CSPs) in chromatography. ► Review period from January 2007 to March 2012. ► The synthetic strategy of CD-CSPs was found to affect ...enantioseparation. ► CD functional groups affect inclusion complexation and molecular interactions.
The current article reviews the development and applications of novel cyclodextrin chiral stationary phases (CD-CSPs) in liquid chromatography (LC), capillary electrochromatography (CEC), gas chromatography (GC) and supercritical fluid chromatography (SFC) over the period of January 2007 to March 2012. The synthetic routes of CD-CSPs, as well as the presence of selective functional groups in effecting inclusion complexation and molecular interactions have been found to exert profound influence in the enantioseparation process. In this article, various synthetic and functional groups immobilization strategies of novel CD-CSPs, and their applications in chiral resolution using different chromatography techniques are discussed. After introducing the topic in Section 1, Section 2 describes novel CD-CSPs in LC applications, where the CSPs are classified according to its coating approaches (physical and chemical manners) for ease of readership. Section 3 discusses recent development of CD-CSPs in open tubular CEC (OT-CEC), packed-bed CEC (P-CEC), pseudostationary phase CEC (PSP-CEC) and monolithic CEC. The last part illustrates novel CD-CSPs in gas chromatography (GC) and supercritical fluid chromatography (SFC).
The greening of analytical methods has gained increasing interest in the field of pharmaceutical analysis to reduce environmental impacts and improve the health safety of analysts. Reversed-phase ...high-performance liquid chromatography (RP-HPLC) is the most widely used analytical technique involved in pharmaceutical drug development and manufacturing, such as the quality control of bulk drugs and pharmaceutical formulations, as well as the analysis of drugs in biological samples. However, RP-HPLC methods commonly use large amounts of organic solvents and generate high quantities of waste to be disposed, leading to some issues in terms of ecological impact and operator safety. In this context, greening HPLC methods is becoming highly desirable. One strategy to reduce the impact of hazardous solvents is to replace classically used organic solvents (i.e., acetonitrile and methanol) with greener ones. So far, ethanol has been the most often used alternative organic solvent. Others strategies have followed, such as the use of totally aqueous mobile phases, micellar liquid chromatography, and ionic liquids. These approaches have been well developed, as they do not require equipment investments and are rather economical. This review describes and critically discusses the recent advances in greening RP-HPLC methods dedicated to pharmaceutical analysis based on the use of alternative solvents.
Affinity monolith chromatography (AMC) is a type of liquid chromatography that uses a monolithic support and a biologically related binding agent as a stationary phase. AMC is a powerful method for ...the selective separation, analysis, or study of specific target compounds in a sample. This review discusses the basic principles of AMC and recent developments and applications of this method, with particular emphasis being given to work that has appeared in the last 5 years. Various materials that have been used to prepare columns for AMC are examined, including organic monoliths, silica monoliths, agarose monoliths, and cryogels. These supports have been used in AMC for formats that have ranged from traditional columns to disks, microcolumns, and capillaries. Many binding agents have also been employed in AMC, such as antibodies, enzymes, proteins, lectins, immobilized metal ions, and dyes. Some applications that have been reported with these binding agents in AMC are bioaffinity chromatography, immunoaffinity chromatography or immunoextraction, immobilized-metal-ion affinity chromatography, dye–ligand affinity chromatography, chiral separations, and biointeraction studies. Examples are presented from fields that include analytical chemistry, pharmaceutical analysis, clinical testing, and biotechnology. Current trends and possible directions in AMC are also discussed.
As a class of mycotoxins with regulatory and public health significance, aflatoxins (e.g., aflatoxin B
, B
, G
and G
) have attracted unparalleled attention from government, academia and industry due ...to their chronic and acute toxicity. Aflatoxins are secondary metabolites of various
species, which are ubiquitous in the environment and can grow on a variety of crops whereby accumulation is impacted by climate influences. Consumption of foods and feeds contaminated by aflatoxins are hazardous to human and animal health, hence the detection and quantification of aflatoxins in foods and feeds is a priority from the viewpoint of food safety. Since the first purification and identification of aflatoxins from feeds in the 1960s, there have been continuous efforts to develop sensitive and rapid methods for the determination of aflatoxins. This review aims to provide a comprehensive overview on advances in aflatoxins analysis and highlights the importance of sample pretreatments, homogenization and various cleanup strategies used in the determination of aflatoxins. The use of liquid-liquid extraction (LLE), supercritical fluid extraction (SFE), solid phase extraction (SPE) and immunoaffinity column clean-up (IAC) and dilute and shoot for enhancing extraction efficiency and clean-up are discussed. Furthermore, the analytical techniques such as gas chromatography (GC), liquid chromatography (LC), mass spectrometry (MS), capillary electrophoresis (CE) and thin-layer chromatography (TLC) are compared in terms of identification, quantitation and throughput. Lastly, with the emergence of new techniques, the review culminates with prospects of promising technologies for aflatoxin analysis in the foreseeable future.
The aim of this study is the development of a separation technique for geological samples, namely bismuthinites, with the goal to isolate Tl from excess amounts of Bi. This will enable an isotopic ...measurement of the Tl content on the ultra-trace level to identify a possible signature of Bi alpha-decay. The separation of Tl from other elements like e.g. Pb has been the subject of numerous studies. However, the separation of ultra-traces of Tl from bulk Bi had not yet been investigated sufficiently. This paper describes a separation technique for the system Bi/Tl for application to ultra-trace analysis. The separation technique uses a column chromatographic system, utilizing the specific redox behavior of Tl. The results show, that Tl can be successfully separated in appearance of vast excess amounts of Bi, showing recovery rates up to 96%. The developed procedure was successfully applied for the ultra-trace analysis on a number of bimuthinites using ICP-MS. On base of the results it is discussed, which prerequisites bimuthinite samples must fulfill to be suitable for the quantification of Bi alpha decay on base of the Tl isotopic ratio.
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