Arsanilic acid (ASA) residue, which is the most common contaminant in edible animal tissues such as pork and liver, has caused environmental and food-safety concerns. In this study, direct and indirect competitive fluorescence-linked immunosorbent assays (dc-FLISA and ic-FLISA) incorporating quantum dots (QDs) as the fluorescent label were developed for the first time to detect ASA residues in edible pork and animal liver. Monoclonal antibodies against ASA and rabbit anti-mouse antibody were conjugated to orange QDs with excitation wavelengths at 450 nm, and the QD-Abs served as detection probes. The limits of detection for dc-FLISA and ic-FLISA were 0.11 ng/mL and 0.001 ng/mL, respectively. QD-FLISA was used to analyse spiked samples; recoveries ranged from 80.2%-91.2% in dc-FLISA and 82.5%-91.2% in ic-FLISA, and the coefficients of variations (CV) were less than 12%. Compared with conventional indirect competitive enzyme-linked immunosorbent assay (ic-ELISA), the QD-FLISA described here was more sensitive and accurate in the analysis of ASA residues in animal tissues. Moreover, the results of QD-FLISA correlated well with HPLC. These results indicate that dc-FLISA and ic-FLISA are sensitive and reliable for detection of ASA residues in edible animal tissues.
Shengnan Chen,Jing Deng,Cheng Ye,Chengcheng Xu,Lingyi Huai,Xiao Ling,Jun Li,Xueyan Li
Pre-magnetized Fe 0 /persulfate (pre-Fe 0 /PS) process was innovatively employed for controlling the pollution of p -arsanilic acid ( p -ASA). This process showed favorable removal performance, achieving almost complete elimination of 10 mg/L p -ASA within 30 min at the reaction conditions of 0.2 g/L pre-Fe 0 and 1 mM PS. The increase of PS concentration and pre-Fe 0 dosage was conducive to the degradation. The coexistence of Cl − , NO 3 − and SO 4 2− accelerated the removal, however the presence of HCO 3 − and HA presented the opposite trend. The p -ASA degradation decelerated gradually with increasing pH from 5 to 9. Its removal was caused by the attack of reactive oxygen species (i.e., SO 4 − , OH, O 2 − ), which could be continuously formed via the Fe 2+ /Fe 3+ cycle in solution and on pre-Fe 0 surface. In pre-Fe 0 /PS system, SO 4 − in solution, surface-bound SO 4 − , OH, OH in solution, O 2 − in solution and Fe(IV) contributed to the p -ASA degradation. A plausible transformation route related to the break of C-N and As-C bonds, the substitution of OH group was put forward. More importantly, the released inorganic arsenic during p -ASA decomposition could be effectively controlled through multiple functions including the precipitation, co-precipitation and sorption, which was well confirmed by XPS, FTIR and XRD analysis. Pre-Fe 0 /PS and Fe 0 /PS pretreatments both reduced the generation of C-DBPs except for chloral hydrate, while increased the formation of N-DBPs except for trichloroacetamide.
危险品化学品经营许可证（带存储）