Regeneration and Reuse of Immunoaffinity Column for Highly Efficient Clean-Up and Economic Detection of Ochratoxin A in Malt and Ginger

Abstract

Immunoaffinity columns (IACs) are most popularly used for mycotoxin clean-up in complex matrices prior to chromatographic analysis. But, their high cost has limited their wide application and the regeneration of IACs for multiple instances of reuse is important. This study aimed to investigate the feasibility of regeneration and reuse of IACs for purification of ochratoxin A (OTA) in spiked raw malt and dried ginger samples followed by high performance liquid chromatography-fluorescence detection. After each use, the IACs were filled with phosphate buffer saline (PBS) as the preservation solution and stored at 8 °C overnight for regeneration and reuse until the recovery rate was <70%. The results showed that matrix type, preparation procedure, and pH value of sample extraction exhibited major effects on the reuse of IACs for OTA clean-up. While, after modifying the sample preparation procedure using water as the diluent and the solution at a pH of 7 to 8, the IACs could be used eight and three times for the spiked raw malt and dried ginger samples with OTA after regeneration. Regarding the traditional procedure recommended in Chinese Pharmacopoeia (2015 edition), the IACs could be used for three and two times for the spiked raw malt and dried ginger samples with OTA, respectively. Therefore, the corresponding experimental cost could be reduced to one-eighth and one-third of the original cost. This is the first study on the regeneration and reuse of IACs for OTA clean-up in complex Chinese herbal medicines, providing a green and economical tool for a large number of samples analysis with low cost.

Aptamer-based and immunosorbents

“…Indeed, despite their susceptibility to irreversible denaturation in some conditions, numerous studies have shown the possibility to reuse ISs after their storage at 4°C in a PBS solution, which is close to physiological conditions and in the presence of an antimicrobial agent such as sodium azide. This possible regeneration was confirmed recently by a detailed study related to the reusability of commercial ISs dedicated to mycotoxin analysis (98). In the same way, despite their sensitivity to nuclease, OSs can be stored at 4°C in a buffer solution, whose composition is close to the binding buffer, and containing also sodium azide.…”

Recent Progress and Development of G-Quadruplex-Based Luminescent Assays for Ochratoxin A Detection

“…In another study, Immunoaffinity column high-performance thin layer chromatography (IM-HPTLC) has also been used to detect OTA with limits of detection <0.28 µg/kg (Chompurat et al, 2007). More recently, an LOD of around 0.4 ng/mL was reported with multitime-regenerated IM (Liu X. et al, 2018). Meanwhile, Yuan et al (2009) reported a rapid and highly sensitive competitive immunoassay coupled to surface plasmon resonance (IM-SPR) for OTA quantification in cereals and beverage.…”

The Existing Methods and Novel Approaches in Mycotoxins’ Detection

“…IACs are very sensitive, selective, and can serve as universal and valid purification tool for tracing the mycotoxins. Furthermore, it is a user-friendly and solvent-saving method because of the antibodies’ specificity [ 65 ]. However, some limitations are linked with this technique.…”

“…Other disadvantages include organic solvents, which can denature or devitalize the antibodies leading to difficulties in the reuse of IACs. Moreover, the operating costs of this method are substantially high [ 65 ]. IAC has been successfully applied in simultaneous analysis of OTA, ZEA, and AFs in wheat bran [ 67 ], OTA, AFs, and Fusarium toxins in maize [ 68 ] and cereals [ 69 ].…”