Artificial neural networks for quantification in unresolved capillary electrophoresis peaks

Latorre, Rosa M.; Hernández-Cassou, Santiago; Saurina, Javier

doi:10.1002/1615-9314(20010601)24:6<427::aid-jssc427>3.0.co;2-1

Cited by 13 publications

(7 citation statements)

References 25 publications

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“…The most commonly used method for the detection of histidine and histidine‐rich proteins in biological samples is chromatography, which is usually performed through the combination of an effective separation technique, such as thin‐layer chromatography, gas chromatography, or HPLC, followed by UV/Vis or fluorescence spectroscopy 2f–h. The use of high‐performance capillary electrophoresis with a derivation reagent has also been reported 2i. However, the aforementioned methods are generally tedious, laborious, and, most importantly, expensive for routine detection in a biochemistry laboratory.…”

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confidence: 99%

A Highly Selective Luminescent Switch‐On Probe for Histidine/Histidine‐Rich Proteins and Its Application in Protein Staining

et al. 2008

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The luminescence sensing of histidine and histidine-rich proteins plays a pivotal role in biochemistry and molecular biology, in particular when both temporal and spatial resolution are required. An abnormal level of histidine-rich proteins is an indicator for many diseases, such as advanced liver cirrhosis, [1a,b] AIDS, [1c] renal disease, [1c] asthma, [1c] pulmonary disorders, [1d] thrombotic disorders, [1e, f] and malaria.[1g]Some analyses of histidine and histidine-rich proteins have been developed in conjunction with immunoassay [2a-d] and colorimetric detection methods.[2e] The most commonly used method for the detection of histidine and histidine-rich proteins in biological samples is chromatography, which is usually performed through the combination of an effective separation technique, such as thin-layer chromatography, gas chromatography, or HPLC, followed by UV/Vis or fluorescence spectroscopy.[2f-h] The use of high-performance capillary electrophoresis with a derivation reagent has also been reported.[2i] However, the aforementioned methods are generally tedious, laborious, and, most importantly, expensive for routine detection in a biochemistry laboratory.Although numerous studies have dealt with the detection of histidine or histidine-rich proteins, studies on the use of luminescent probes for this purpose remain sparse.[3] Notable examples include research by Fabbrizzi and co-workers, who developed competitive noncovalent fluorescence turn-on probes for histidine in the form of dizinc(II) or dicopper(II) macrocyclic complexes, which recognize histidine through the formation of an imidazolate bridge between the two dizinc(II) or dicopper(II) centers; [3a] however, the resulting noncovalent ensemble may be less stable than a covalently linking sensory system, and the complexity of the synthetic process makes it difficult to implement in a convenient manner.Photoluminescent iridium(III) complexes have emerged as a topical area of interest in inorganic photochemistry [4] and phosphorescent materials for optoelectronic [5] and luminescence signaling applications.[6] Significant changes in the photophysical behavior and emission properties of iridium-(III) complexes may be induced by the presence of biomolecules. Luminescent transition-metal complexes for protein staining, such as the luminescent ruthenium complex known as SYPRO Ruby dye, have been reported previously. [7] However, despite its high sensitivity and its broad dynamic range, the use of SYPRO Ruby dye is limited, as it is sold only as a formulated solution; therefore, it is not possible to optimize the dye for a particular electrophoresis protocol and protein. + , and the iridium complex is readily soluble and stable in aqueous staining solutions. In this study, [Ir(ppy) 3 ] (2) was also prepared for comparative studies, as its binding with proteins was expected to be largely hydrophobic in nature. Herein, we describe the luminescent switch-on probe [Ir(ppy) 2 (solv) 2 ] + (1) for histidine/histidinerich proteins and demonstrate...

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A Highly Selective Luminescent Switch‐On Probe for Histidine/Histidine‐Rich Proteins and Its Application in Protein Staining

et al. 2008

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“…Iso-propanol has been used as the organic modifier to improve resolution of the amino acid derivatives. 5,20,21 Our preliminary study, using iso-propanol resulted in an unstable (fluctuating) baseline, so acetonitrile (ACN) was used instead. The effect of ACN was studied at 70 mmol L -1 borate buffer pH 10.0 and ACN was varied in the range of 5 -15 %.…”

Section: Effect Of Organic Modifiermentioning

confidence: 99%

“…5,20,21 NQS has several important characteristics including solubility in water at any pH and ability to react with primary and secondary amino groups and aromatic primary amino groups. 21 The aim of the present study is to optimise CZE for simultaneous determination of seven amino acids (alanine (Ala), asparagine (Asn), leucine (Leu), lysine (Lys), proline (Pro), tyrosine (Tyr) and valine (Val)) using NQS as the labelling reagent. As a preliminary application, this method was applied to determine amino acids in some beverages: wines, beers and fruit juices.…”

Section: Introductionmentioning

confidence: 99%

Pre‐Capillary Derivatisation and Capillary Zone Electrophoresis for Amino Acids Analysis in Beverages

et al. 2007

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A simple and rapid method for the simultaneous analysis of amino acids has been developed. Amino acids were derivatised based on pre-capillary derivatisation with 1,2-naphthoquinone-4-sulfonate (NQS) in basic medium (pH 10.0) and developed reaction at 70 degrees C. Their derivatives were analysed by capillary zone electrophoresis (CZE). The parameters affecting CZE separation were investigated including buffer (pH, type and concentration), organic modifier and separation voltage. The optimum condition was 70 mmol L(-1) borate (pH 10.0) containing 10% acetonitrile, separation voltage of 12 kV, and sample injection (0.5 psi, 5s) and on-capillary detection at 240 nm. The separation of seven amino acids was achieved within 17 min. The detection limit was 1.0 mg L(-1) for all studied amino acids. The calibration curves were linear in the concentration range of 1.0-100.0 mg L(-1). The repeatability, intra-day and inter-day analysis were < or = 1.0% and < or = 2.0% for migration time and < or = 5.0% and 6.0% for peak area. The proposed method has been applied to several beverage samples with only a simple dilution and filtration treatment of sample before derivatisation and analysed by CZE.

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“…When physical separation of sample components is not fully accomplished, identification and quantification difficulties from poorly resolved peaks may still be overcome mathematically and effectively by using chemometric tools [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16], which is becoming an interesting study field for CE workers. Many chemometric methods have been used in CE, such as principal component regression (PCR) [1], partial least squares regression (PLS) [1,2], artificial neural networks (ANN) [3][4][5][6][7][8][9], and multivariate curve resolution with alternating least square (MCR-ALS) [10][11][12][13][14][15][16], tackling problems in CE such as the study of peak purity and deconvolution of comigrations, and the quantification of the analytes in poorly resolved peaks. Sònia Sentellas and Javier Saurina have reviewed the application of chemometrics in CE in two paper [17,18], in which chemometric techniques to optimize CE separations (part a) and to extract relevant information (part b) are introduced.…”

Section: Introductionmentioning

confidence: 99%

Application of Multivariate curve resolution‐alternating least square methods on the resolution of overlapping CE peaks from different separation conditions

2007

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Discussed in this paper is the development of a new strategy to improve resolution of overlapping CE peaks by using second-order multivariate curve resolution with alternating least square (second-order MCR-ALS) methods. Several kinds of organic reagents are added, respectively, in buffers and sets of overlapping peaks with different separations are obtained. Augmented matrix is formed by the corresponding matrices of the overlapping peaks and is then analyzed by the second-order MCR-ALS method in order to use all data information to improve the precision of the resolution. Similarity between the resolved unit spectrum and the true one is used to assess the quality of the solutions provided by the above method. 3,4-Dihydropyrimidin-2-one derivatives (DHPOs) are used as model components and mixed artificially in order to obtain overlapping peaks. Three different impurity levels, 100, 20, and 10% relative to the main component, are used. With this strategy, the concentration profiles and spectra of impurities, which are no more than 10% of the main component, can be resolved from the overlapping peaks without pure standards participant in the analysis. The effects of the changes in the components spectra in the buffer with different organic reagents on the resolution are also evaluated, which are slight and can thus be ignored in the analysis. Individual data matrices (two-way data) are also analyzed by using MCR-ALS and heuristic evolving latent projections (HELP) methods and their results are compared with those when MCR-ALS is applied to augmented data matrix (three-way data) analysis.

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Artificial neural networks for quantification in unresolved capillary electrophoresis peaks

Cited by 13 publications

References 25 publications

A Highly Selective Luminescent Switch‐On Probe for Histidine/Histidine‐Rich Proteins and Its Application in Protein Staining

A Highly Selective Luminescent Switch‐On Probe for Histidine/Histidine‐Rich Proteins and Its Application in Protein Staining

Pre‐Capillary Derivatisation and Capillary Zone Electrophoresis for Amino Acids Analysis in Beverages

Application of Multivariate curve resolution‐alternating least square methods on the resolution of overlapping CE peaks from different separation conditions

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