Immunoaffinity coupling

Figure 3 Schemes for coupling immunoaffinity chromatography with other HPLC separation steps. Symbols as s in Fig. 2. ...

G. S. Rule, A. V. Moi dehai and J. Henion, Determination of carbofuran by on-line immunoaffinity cliromatography with coupled-column liquid chromatography/mass spectrometiy . Aim/. Chem. 66 230-235 (1994). 

J. Cai and J. Henion, Quantitative multi-residue determination of /3-agonists in bovine urine using on-line immunoaffinity extr action-coupled column packed capillary liquid cliromatogr aphy-tandem mass spectr ometry , 7. Chromatogr. 691 357-370 (1997). 

Analogous to two-dimensional LC, the on-line coupling of LC and CE has been carried out both in the heart-cut and the comprehensive mode. In a heart-cut LC-CE study, a protein G immunoaffinity LC column was used to selectively preconcentrate insulin from serum (171). A 1 p.1 elution plug comprising the insulin was switched on-line to the CE system where a part was injected into the capillary for final separation. With CE, efficient separations can be obtained in a... 

A. Farjam, N. C. van de Merbel, A. A. Nieman, H. Lingeman and U. A. Th Brinkman, Determination of aflatoxin Ml using a dialysis-based immunoaffinity sample pretreat-ment system coupled on-line to liquid cliromatography , ]. Chromatogr. 589 141-149(1992). 

J. Cai and J. Henion, On-line immunoaffinity exti action-coupled column capillary liquid cliromatography/tandem mass specb omeb y trace analysis of LSD analogs and metabolites in human urine . Anal. Chem. 68 72-78 (1996). 

The low selectivity of the SPE columns currently in use can be increased with more selective sorbents such as the immunosorbents, which have been quite extensively used in SPE-LC (72). Immunoaffinity-based solid-phase extraction (lASPE) sorbents have also been used in coupled gas chromatography for determining... 

Figure 13.20 GC-FID chromatograms of an exuact obtained by (a) SPE and, (b) lASPE of 10 ml of municipal waste water, spiked with 1 p.g 1 of seven s-triazines (c) represents a blank mn from lASPE-GC-NPD of 10 ml of EIPLC water. Peak identification is as follows 1, ati azine 2, terbuthylazine 3, sebuthylazine 4, simetiyn 5, prometiyn 6, terbutiyn 7, dipropetiyn. Reprinted from Journal of Chromatography, A 830, J. Dalliige et al, On-line coupling of immunoaffinity-based solid-phase exUaction and gas chi-omatography for the determination of 5-triazines in aqueous samples , pp. 377-386, copyright 1999, with permission from Elsevier Science.

J. Dalliige, T. Hankemeier, J. J. Vreuls and U. A. Th Brinkman, On-line coupling of immunoaffinity-based solid-phase extr action and gas chr omatography for the determination of 5-triazines in aqueous samples , 7. Chromatogr. 830 377-386 (1999). 

The antibody of human epidermal growth factor (EGF) was coupled to diol silica (prepared from silica and 3-glycidoxypropyltrimethoxysilane via an epoxy silica) by means of CDI. This supported antibody was utilized for immunoaffinity HPLC analysis of human epidermal growth factor. 213 ... 

Immunoaffinity procedures can be performed either on-line or off-line, and can be coupled to chromatographic systems [ 118,119] or even to immunoassays [120]. Many examples can be found in the literature regarding the use of immunoaffinity extraction of drugs and pharmaceuticals from biological matrices, as well as of organic pollutants such as pesticides from environmental samples [115,121-124]. 

Affinity-purified antibodies are isolated from antisera by immunoaffinity chromatography using antigens coupled to agarose beads. 

Fazekas, B. and Tar, A., Determination of zearalenone content in cereals and feedstuff s by immunoaffinity column coupled with liquid chromatography, J. AO AC Int., 84, 1453, 2001. 

A technique called on-line immunoaffinity CE has been presented (45) that was also coupled to MS. However, in this setup the affinity principle is used to extract the analyte from a complex matrix in a microchamber affinity device prior to CE separation. Therefore, it cannot be considered ACE. 

NA Guzman. Determination of immunoreactive gonadotropin-releasing hormone in serum and urine by on-line immunoaffinity capillary electrophoresis coupled to mass spectrometry. J Chromatogr B 749 197—213, 2000. 

In addition to the commercially available systems, several authors have described laboratory-built systems using commercially available components from companies such as Upchurch Scientific (Oak Harbor, WA). One of the first reported laboratory-built micro-bore HPLC systems was described by Simpson and Brown, which was a simple adaptation of a standard HPLC system to accept micro-bore columns built from guard columns. A complete system has been described based on dual microdialysis syringe pumps (CMA Microdialysis, Chelmsford, M A) or dual syringe pumps (Harvard Apparatus, Inc., Holliston, MA), a microinjection port, and a micro-column the latter components being obtained from Upchurch scientific (Figure 3.5). This system was coupled with a laser-induced fluorescence (LIF) detector and used to measure neuropeptides in sub-microliter samples. A further modification of this system was built to perform immunoaffinity isolations of biomedically important analytes from clinical samples. ... 

Immunoaffinity chromatography cleanup has also been applied as an ideal and reliable strategy for residue analysis. Immunoaffinity columns prepared by coupling the antibodies to a cyanogen bromide-activated support were used to analyze avermectin BI residues in cattle tissues (359) and ivermectin in sheep serum (376). An immunoaffinity column prepared by an alternative activation/ coupling procedure with carbonyl diimidazole was also employed to analyze ivermectin residues in swine liver (361) since the earlier-reported methods did not work well in the analysis of this matrix. This recent work demonstrated the high specificity of tire antibody-mediated cleanup, but also showed that the immunoaffinity procedures could not always or completely eliminate matrix interference of samples. Therefore, application of additional cleanup steps before or after these procedures is often inevitable. 

Addition of appropriate amounts of salts, such as ammonium or sodium sulfate (2), or other chemicals, such as PEG, cause precipitation of IgG from serum. Caprylic acid can also be used to fractionate proteins from serum Although such IgG is usually contaminated with other proteins, the ease of these precipitation procedures coupled with the high yield of IgG produced has led to them being very widely used to produce enriched IgG preparations suitable for many immunochemical procedures, e.g., production of immunoaffinity columns, and as a starting point for further purification. The precipitated IgG is usually very stable and such preparations are ideally suited for long-term storage or distribution and exchange between laboratories. 

MW Trucksess, ME Stack, S Nesheim, SW Page, RH Albert, TJ Hansen, KF Donahue. Immunoaffinity column coupled with solution fluorometry or liquid chromatography post-column derivati-... 

Multi-immunoaffinity chromatography columns were prepared by the coupling of monoclonal antibodies against AMP to activated sepharose. Both sensitivity and specificity were tested for the most commonly used penicillins (AMP, AMO, PenG, OXA, CLO, DICL). Recoveries ranging from 67% to 100% were obtained from phosphate buffer solutions, and it was assumed... 

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