Ion Exclusion Chromatography of Aromatic Acids

Mansour, Fotouh R.; Kirkpatrick, Christine L.; Danielson, Neil D.

doi:10.1093/chromsci/bmt007

Cited by 17 publications

(11 citation statements)

References 56 publications

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“…Ion chromatography (IC) represents a group of techniques that can be used to separate ionic species and low molecular weight acids or bases that are either too weakly retained in RPLC or too strongly retained on NPLC columns (Fritz and Gjerde, ). The separation mechanisms in IC include (1) ion exchange owing to attraction between the oppositely charged analyte and stationary phase, (2) ion exclusion owing to the repulsion of the similarly charged analyte and stationary phase (Mansour et al ., ), and (3) ion pair liquid chromatography (IPLC). In IPLC, a reversed‐phase column is used and the ionic analyte species are injected in a mobile phase that contains an oppositely charged organic ion, which can ion‐pair and/or act as a dynamic ion exchanger with the analytes (Buszewski, ).…”

Section: Methodsmentioning

confidence: 99%

Separation of carnitine and acylcarnitines in biological samples: a review

Mansour

Wei

Danielson

2013

Biomedical Chromatography

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Carnitine and its acylesters are a family of compounds that can be used in the early diagnosis of many diseases. Carnitine and acylcarnitines have a crucial role in fatty acid transportation. The increased level of free carnitine, total carnitine, or the acylesters can act as biomarkers for many metabolic disorders, including diabetes, encephalopathy and cardiomyopathy. The determination of these compounds is difficult owing to the simple aliphatic structure, the chiral center and the permanent positive charge. Although MS detection can be enough to differentiate between some carnitine derivatives, closely related structural isomers of the acylcarnitines must be separated before detection because they form the same base peak and second most abundant ion peak. Different separation methods are discussed in this review, including reversed-phase, hydrophilic interaction, ion exchange, ion pairing, mixed mode liquid chromatography, gas chromatography and electrophoresis. Representative example chromatograms are shown. The sample preparation and the different derivatization reactions are also covered. A table that summarizes the most important analytical methods by detailing the analyte mixture, the sample matrix, the separation mode and the detection method is provided.

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Section: Methodsmentioning

confidence: 99%

Separation of carnitine and acylcarnitines in biological samples: a review

Mansour

Wei

Danielson

2013

Biomedical Chromatography

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“…In liquid chromatography, three major separation techniques must be mentioned with respect to AAD: (i) ion chromatography (IC), (ii) reversed-phase (RP) and (iii) hydrophilic interaction chromatography (HILIC), usually performed as HPLC with a higher separation efficiency. IC is the traditional method in AA analysis based on the separation of polar analytes by their varying affinity to a stationary ion exchanger (Mansour et al, 2013;Williams, 1986). While ion exchange as phenomenon was already described in the mid-19 th century (Way, 1850(Way, , 1852, and synthesis of the first ion exchange resins was published in 1935 by Adams and Holmes (Adams, 1935), it was not until the work by Small, Stevens andBaumann in 1975 (Small et al, 1975) that IC gained real foothold in analytical chemistry.…”

Section: From Liquid To Gas Chromatographymentioning

confidence: 99%

The why and how of amino acid analytics in cancer diagnostics and therapy

Manig

Kuhne

Neubeck

et al. 2017

Journal of Biotechnology

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Pathological alterations in cell functions are frequently accompanied by metabolic reprogramming including modifications in amino acid metabolism. Amino acid detection is thus integral to the diagnosis of many hereditary metabolic diseases. The development of malignant diseases as metabolic disorders comes along with a complex dysregulation of genetic and epigenetic factors affecting metabolic enzymes. Cancer cells might transiently or permanently become auxotrophic for non-essential or semi-essential amino acids such as asparagine or arginine. Also, transformed cells are often more susceptible to local shortage of essential amino acids such as methionine than normal tissues. This offers new points of attacking unique metabolic features in cancer cells. To better understand these processes, highly sensitive methods for amino acid detection and quantification are required. Our review summarizes the main methodologies for amino acid detection with a particular focus on applications in biomedicine and cancer, provides a historical overview of the methodological pre-requisites in amino acid analytics. We compare classical and modern approaches such as the combination of gas chromatography and liquid chromatography with mass spectrometry (GC-MS/LC-MS). The latter is increasingly applied in clinical routine. We therefore illustrate an LC-MS workflow for analyzing arginine and methionine as well as their precursors and analogs in biological material. Pitfalls during protocol development are discussed, but LC-MS emerges as a reliable and sensitive tool for the detection of amino acids in biological matrices. Quantification is challenging, but of particular interest in cancer research as targeting arginine and methionine turnover in cancer cells represent novel treatment strategies.

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“…Simple aliphatic carboxylic acids (e.g., formate, acetate, propionate, and butyrate) can easily be separated by IELC using mineral acids as eluents [2, 3]. The separation of aromatic acids is more difficult due to peak tailing and long retention time caused by the π-π interaction of these analytes with the aromatic rings of the polymeric stationary phase [4, 5]. To avoid this interaction between the aromatic solutes and hydrophobic stationary phase, hydrophilic silica-based columns [6] were used.…”

Section: Introductionmentioning

confidence: 99%

“…Both strong [9] and weak [10-13] cation exchange resins were employed and the technique was also applicable for haloacids [11], inorganic acids [13], aliphatic acids [14], and aliphatic amines [15]. However, the long equilibration time between runs compromises using these methods in routine analysis [5]. …”

Section: Introductionmentioning

confidence: 99%

Separation of Aliphatic and Aromatic Carboxylic Acids by Conventional and Ultra High-Performance Ion-Exclusion Chromatography

2013

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An ion exclusion chromatography (IELC) comparison between a conventional ion exchange column and an ultra-high performance liquid chromatography (UHPLC) dynamically surfactant modified C18 column for the separation of an aliphatic carboxylic acid and two aromatic carboxylic acids is presented. Professional software is used to optimize the conventional IELC separation conditions for acetylsalicylic acid and the hydrolysis products: salicylic acid and acetic acid. Four different variables are simultaneously optimized including H2SO4 concentration, pH, flow rate, and sample injection volume. Thirty different runs are suggested by the software. The resolutions and the time of each run are calculated and feed back to the software to predict the optimum conditions. Derringer’s desirability functions are used to evaluate the test conditions and those with the highest desirability value are utilized to separate acetylsalicylic acid, salicylic acid, and acetic acid. These conditions include using a 0.35 mM H2SO4 (pH 3.93) eluent at a flow rate of 1 mL min-1 and an injection volume of 72 μL. To decrease the run time and improve the performance, a UHPLC C18 column is used after dynamic modification with sodium dodecyl sulfate. Using pure water as a mobile phase, a shorter analysis time and better resolution are achieved. In addition, the elution order is different from the IELC method which indicates the contribution of the reversed-phase mode to the separation mechanism.

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Ion Exclusion Chromatography of Aromatic Acids

Cited by 17 publications

References 56 publications

Separation of carnitine and acylcarnitines in biological samples: a review

Separation of carnitine and acylcarnitines in biological samples: a review

The why and how of amino acid analytics in cancer diagnostics and therapy

Separation of Aliphatic and Aromatic Carboxylic Acids by Conventional and Ultra High-Performance Ion-Exclusion Chromatography

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