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HPLC separation and square‐wave adsorptive‐stripping detection of human immunoglobulin G and A
Author(s) -
Zhang Li Qun,
Sturrock Peter E.
Publication year - 1990
Publication title -
electroanalysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.574
H-Index - 128
eISSN - 1521-4109
pISSN - 1040-0397
DOI - 10.1002/elan.1140020405
Subject(s) - chemistry , chromatography , stripping (fiber) , high performance liquid chromatography , buffer solution , immunoglobulin g , calibration curve , phosphate buffered saline , linear range , analytical chemistry (journal) , detection limit , immunoglobulin a , antibody , immunology , materials science , biology , composite material
Human immunoglobulin G and A (IgG and IgA) were studied with square‐wave voltammetry. For IgG, three reduction peaks (HIGG1, HIGG2, and HIGG3) were observed under different conditions. HIGG1 and HIGG3 are strongly related to the pH of the buffer solution. In pH 7.5 phosphate buffer, the peak potential of HIGG2 is −0.58 V (vs. Ag/AgCl). A linear response holds for human IgG below 3.3 × 10 −8 M (5 ppm). As little as 1.1 × 10 −10 M (16 ppb) of human IgG is detectable after only 20 seconds of adsorptive accumulation in static solution. IgA has two flat adsorptive‐stripping responses (HIGA1 and HIGA2). The sensitivity of IgA is much poorer compared to IgG. HIGA2 at −0.44 V can be observed throughout the tested pH range with the maximum response between pH 6.0–6.2. In a static solution, a linear calibration graph can be obtained for 0.8–16.8 ppm IgA. IgG and IgA can be separated from each other by using HPLC with an AB × column. The response of 32 ppb IgG can be observed clearly. This research indicates the possibility of direct separation and detection of immunoglobulins from a real sample (e.g., human serum) by simply applying HPLC‐adsorptive‐stripping analysis.