Sensitive Quantitative Analysis of C-Peptide in Human Plasma by 2-Dimensional Liquid Chromatography–Mass Spectrometry Isotope-Dilution Assay

Rogatsky, Eduard; Balent, Beate; Goswami, Gayotri; Tomuta, Vlad; Jayatillake, Harsha; Cruikshank, Greg; Vele, Louis; Stein, Daniel T.

doi:10.1373/clinchem.2005.063081

Cited by 44 publications

(49 citation statements)

References 27 publications

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“…Thus, it has been recognised for some time that C-peptide results from different immunoassays do not always agree and that there is a need for harmonisation of these assays. There have been a number of recent reports demonstrating the potential role of calibrators, prepared in a sample matrix and value-assigned using a reference method, in improving the between-method agreement of C-peptide measurements in patient samples (9)(10)(11)(12). This effort is now underway, with significant progress reported by the NIDDK C-peptide standardisation committee (R. Little, personal communication).…”

Section: Discussionmentioning

confidence: 99%

Preparation, calibration and evaluation of the First International Standard for human C-peptide

Moore

Dougall

Ferguson

et al. 2017

Clinical Chemistry and Laboratory Medicine (CCLM)

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Background: Measurement of C-peptide by immunoassay contributes to the diagnosis of a number of disorders related to β cell function. Stocks of the current international reference reagent (IRR) for C-peptide, used to calibrate these immunoassays, are exhausted, and this report summarises the international study to establish a replacement World Health Organization (WHO) international standard (IS) to maintain the availability of a globally available reference material and support efforts to standardise C-peptide assays. Methods: The study was conducted in three phases; phase I involved the assignment of a value to a primary calibrant in mass units by amino acid analysis and phase II applied this value to the calibration of a candidate standard, 13/146, by reversed phase high-performance liquid chromatography (RP-HPLC) assay. In phase III, the candidate standard was compared to the first IRR by current immunoassays to assess its suitability to serve as an IS. Results: Calibration of the candidate standard by RP-HPLC gave a final estimated content of 8.64 μg/ampoule with expanded uncertainty of 8.21-9.07 μg/ampoule (95% confidence; k = 2.45). The candidate standard also appears sufficiently stable to serve as an IS, based on HPLC analysis of accelerated thermal degradation samples of 13/146, and was also shown to have appropriate immunological activity. A difference in bias approach was used to assess the commutability of 13/146 with human serum and urine samples. With the exception of two laboratories, the candidate standard demonstrated commutability with respect to the serum and urine samples included in this study. Conclusions:The candidate standard, 13/146, is suitable to serve as the First International Standard for human

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Section: Discussionmentioning

confidence: 99%

Preparation, calibration and evaluation of the First International Standard for human C-peptide

Moore

Dougall

Ferguson

et al. 2017

Clinical Chemistry and Laboratory Medicine (CCLM)

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“…Direct, highly rugged and accurate analysis of insulin is considerably more challenging due to its higher clearance (and thus lower plasma concentration), and the high variance of measurement by established immunoassays. Sensitive LC/MS analysis has been proposed as a candidate reference method for C-peptide analysis, and has become an invaluable tool for improving our understanding of and diagnosis of diabetes [5,6]. While urinary C-peptide analysis is quite simple [7,8], plasma concentrations (especially fasting) do not exceed 2 ng/ml in non diabetic and Type 2 diabetic subjects.…”

Section: Fused Core Particle In 2d Chromatographymentioning

confidence: 99%

Application of Fused-Core Particle Column in Two Dimensional Reversed Phase - Reversed Phase LC/MS Analysis of Biological Samples. Impact of Extra-Column Volume

Rogatsky¹

2012

J Chromat Separation Techniq

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We demonstrate successful applicability of fused-core column in analysis of biological samples (diluted urine and SPE-pre-purified plasma or serum) using 2 dimensional chromatography. Implementation of fused-core material in the second dimension of 2D chromatographic platform allowed improving S/N above 4 fold in comparison to traditional porous C18 column. Sample load onto the first dimension (5 µm) eliminates limitations of sample volume to be injected. The main limitation factor of the fused-core material-low loading capacity was overcome by using 2D chromatography. We emphasize importance of reduction of post-column (extra column) volume in LC/MS applications utilizing fused-core columns.

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“…Frequently, the most abundant product ions have only one or two amino acid residues, which are not highly specific. This situation is a potential reason for "false positive" signals [4]. When collision induced dissociation (CID) results in a number of fragments, frequently the detection method is based on the transition which provides the most intensive signal, although depending on the structure and physical properties of the compound analyzed, its LC/ MS analysis can be done based in different transitions.…”

Section: Introductionmentioning

confidence: 99%

“…We have developed IDA reference methods for plasma and urinary C-peptide that applies isotope dilution electrospray ionization (ESI) and collisioninduced dissociation (CID) of the triple charged peptide [6,7]. C-peptide is known as the definitive biomarker for insulin secretion.…”

Section: Introductionmentioning

confidence: 99%

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Simultaneous Monitoring of Multiple Transitions in Mass Spectrometric Analysis Improves Limit of Detection for Low Abundance Substances in Complex Biological Samples

Rogatsky¹

2013

J Chromat Separation Techniq

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In mass-spectrometry, simultaneous monitoring of several transitions enables increased assay specificity, but also can be used as a tool to improve the lower limit of quantification. In this report, we propose a new approach to low abundant analyte detection in complex samples. The method consists of collecting two and potentially more, different mass spectrometry transitions with further analysis of a product function. For example, C-peptide detection was evaluated with two transitions monitored (1007.7-147.2 and 1007.7-927.8). Further extension of the method is theoretically analyzed and its potential limitations are discussed.

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Sensitive Quantitative Analysis of C-Peptide in Human Plasma by 2-Dimensional Liquid Chromatography–Mass Spectrometry Isotope-Dilution Assay

Cited by 44 publications

References 27 publications

Preparation, calibration and evaluation of the First International Standard for human C-peptide

Preparation, calibration and evaluation of the First International Standard for human C-peptide

Application of Fused-Core Particle Column in Two Dimensional Reversed Phase - Reversed Phase LC/MS Analysis of Biological Samples. Impact of Extra-Column Volume

Simultaneous Monitoring of Multiple Transitions in Mass Spectrometric Analysis Improves Limit of Detection for Low Abundance Substances in Complex Biological Samples

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