Establishment of an Indirect Competitive Enzyme-Linked Immunosorbent Method for the Detection of Heavy Metal Cadmium in Food Packaging Materials

Abstract

Heavy metals in food packaging materials have been indicated to release into the environment at slow rates. Heavy metal contamination, especially that of cadmium (Cd), is widely acknowledged as a global environment threat that leads to continuous growing pollution levels in the environment. Traditionally, the detection of the concentration of Cd relies on expensive precision instruments, such as inductively coupled plasma mass spectrometry (ICP-MS) and inductively coupled plasma-atomic emission spectrometry (ICP-AES). In this study, an indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) based on a specific monoclonal antibody was proposed to rapidly detect Cd. The half-inhibitory concentration and detection sensitivity of the anti-cadmium monoclonal antibody of the ic-ELISA were 5.53 ng mL−1 and 0.35 ng mL−1, respectively. The anti-Cd monoclonal antibody possessed high specificity while diagnosising other heavy metal ions, including Al (III), Ca (II), Cu (II), Fe (III), Hg (II), Mg (II), Mn (II), Pb (II), Zn (II), Cr (III) and Ni (II). The average recovery rates of Cd ranged from 89.03–95.81% in the spiked samples of packing materials, with intra- and inter-board variation coefficients of 7.20% and 6.74%, respectively. The ic-ELISA for Cd detection was applied on 72 food packaging samples that consisted of three material categories—ceramic, glass and paper. Comparison of the detection results with ICP-AES verified the accuracy of the ic-ELISA. The correlation coefficient between the ic-ELISA and the ICP-AES methods was 0.9634, demonstrating that the proposed ic-ELISA approach could be a useful and effective tool for the rapid detection of Cd in food packaging materials.

The Distribution of Selected Toxic Elements in Sauced Chicken during Their Feeding, Processing, and Storage Stages

“…The migration of toxic elements from packaging materials is an important source of chicken contamination [ 40 , 41 ]. The content fluctuation of the four typical toxic elements in the sauced chicken during the storage stage is indicated in Figure 4 .…”

Fluorescence detection of malachite green and cations (Cr3+, Fe3+ and Cu2+) by a europium-based coordination polymer

“…Traditional detection methods for heavy metal ions include ultraviolet spectrometry (UV), [23][24][25][26][27][28][29] atomic absorption spectrometry (AAS), 30,31 uorescence spectrometry (FS), [32][33][34][35][36][37] and inductively coupled plasma mass spectrometry (ICP-MS). [38][39][40][41] Among these methods, uorescence spectrometry has been used widely because it is simple, fast, precise and cost-effective. 42,43 It is necessary to design new chemical sensors for the efficient detection of trace metal ions in environmental chemistry.…”

Indirect Competitive ELISA for the Determination of Total Chromium Content in Food, Feed and Environmental Samples

“…Compared with physical and chemical analysis methods, such as GFAAS, FAAS, ICP-MS, ICP-OES, etc., and other immunoassays such as gold immunochromatographic assay (GICA), fluorescence polarization immunoassay (FPIA), etc., although the icELISA has some defects—such as it is easily affected by environmental and reaction conditions, poor stability, strong nonspecific reaction, prone to false positive results, and strict requirements for sample pretreatment—it has become a fundamental method in the detection of heavy metal ion chelates due to its strong selectivity, high sensitivity, speed and simplicity, large sample screening volume and field operation. Up to now, icELISA methods for the determination of Cd(II) [ 20 , 21 ], Hg(II) [ 22 , 23 ], Pb(II) [ 24 ] and so on have been established. Sasaki et al [ 25 ] developed a Cr ion immunodetector with a limit of detection (LOD) of 1.6 μg/L; Liu et al [ 11 ]and Zou et al [ 26 ] developed a Cr ion colloidal gold immunochromatographic test strip with a LOD of 50 μg/L and 0.1 μg/L, respectively; and Yao et al [ 17 ] developed a Cr(III) plasma ELISA with a LOD of 3.13 μg/L.…”