Development of a sensitive size exclusion HPLC method with fluorescence detection for the quantitation of recombinant human erythropoietin (r-HuEPO) aggregates

Abstract A rapid and accurate size-exclusion HPLC method for the quantitation of polysorbate 80 (PS80) in Houttuynia cordata injection, a Chinese traditional medicine, was developed and validated. The assay was conducted on an Agilent 1100 HPLC system with a TosoHaas TSKgel G2000 SWXL column (30 cm 7.8 mm, 5 m particle size) and an Alltech evaporative light-scattering detector (ELSD) 2000. The mobile phase was 20 mmoL/L ammonium acetateacetonitrile (90 + 10, v/v) delivered at a flow rate of 0.6 mL/min under isocratic conditions. The ELSD was operated in the impactor off mode, the drift tube temperature was set at 110C, and nitrogen flow was maintained at 2.3 L/min. The LOD was 0.25 mg/mL. Linearity was obtained between the log of concentration (C) and the log of peak area (Y) of PS80 in the range of 0.520 mg/mL according to the equation: Log Y = 1.4529 Log C 0.8232 (r2 = 0.9976). An RSD of 1.6 (n = 6) for the determination demonstrated the good precision of the optimized method. PS80 content in several commercial H. cordata injection products from different manufacturers was determined. The data for PS80 content is useful in evaluation of the safety of the products from different manufacturers.

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Coelution of Other Proteins with Albumin during Size-Exclusion HPLC: Implications for Analysis of Urinary Albumin

Clinical Chemistry ◽

10.1373/clinchem.2005.057323 ◽

2006 ◽

Vol 52 (3) ◽

pp. 389-397 ◽

Cited By ~ 54

Author(s):

Denis Sviridov ◽

Bonnie Meilinger ◽

Steven K Drake ◽

Gerard T Hoehn ◽

Glen L Hortin

Keyword(s):

Mass Spectrometry ◽

Reversed Phase ◽

Hplc Method ◽

Urinary Albumin ◽

Size Exclusion ◽

Albumin Concentration ◽

Reversed Phase Hplc ◽

Multiple Components ◽

Size Exclusion Hplc ◽

Phosphate Buffered Saline

Abstract Background: Size-exclusion HPLC has been used as an alternative to immunoassays for quantifying urinary albumin (microalbumin). Systematically higher values for the HPLC method have been proposed to result from nonimmunoreactive albumin. Methods: We evaluated separation of purified proteins and urinary components by size-exclusion HPLC using a Zorbax Bio Series GF-250 column eluted with phosphate-buffered saline. Urinary components eluting in the “albumin” peak were analyzed by mass spectrometry and reversed-phase HPLC. Results: Several proteins, such as transferrin, α1-proteinase inhibitor, α1-acid glycoprotein, and α2-HS glycoprotein, analyzed as purified components, were not resolved from albumin by size-exclusion HPLC. Peaks for other proteins, such as IgG and urinary components identified as dimers of α1-microglobulin and immunoglobulin light chains, overlapped with the albumin peak. Profiles of urine specimens showed variable amounts of components overlapping with albumin. Furthermore, the albumin peak obtained by size-exclusion HPLC was found by mass spectrometry and reversed-phase HPLC to contain multiple components in addition to albumin. Conclusions: Size-exclusion HPLC does not resolve albumin from several other proteins in urine. The albumin peak resolved by this technique, although predominantly composed of albumin, contains several coeluting globulins that would contribute to overestimation of albumin concentration by size-exclusion HPLC.

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