Europium Nanoparticle-Based Lateral Flow Strip Biosensors for the Detection of Quinoxaline Antibiotics and Their Main Metabolites in Fish Feeds and Tissues.

Olaquindox (OLA) and quinocetone (QCT) have been prohibited in aquatic products due to their significant toxicity and side effects. In this study, rapid and visual europium nanoparticle (EuNP)-based lateral flow strip biosensors (LFSBs) were developed for the simultaneous quantitative detection of OLA, QCT, and 3-methyl-quinoxaline-2-carboxylic acid (MQCA) in fish feed and tissue. The EuNP-LFSBs enabled sensitive detection for OLA, QCT, and MQCA with a limit of detection of 0.067, 0.017, and 0.099 ng/mL (R2 ≥ 0.9776) within 10 min. The average recovery of the EuNP-LFSBs was 95.13%, and relative standard deviations were below 9.38%. The method was verified by high-performance liquid chromatography (HPLC), and the test results were consistent. Therefore, the proposed LFSBs serve as a powerful tool to monitor quinoxalines in fish feeds and their residues in fish tissues.

Rapid immunoassays for the detection of quinoxalines and their metabolites residues in animal-derived foods: A review.

Quinoxalines are a class of veterinary drugs with antibacterial and growth-promoting functions. They are often widely used to treat and prevent animal diseases and are illegally used as animal growth promoters to increase economic benefits. Quinoxalines could be easily metabolized in animals to various residue markers and remain in animal-derived foods, which would pose a serious threat to human health. Consequently, it is necessary to detect the residues of quinoxalines and their metabolites. This article reviewed and evaluated immunoassays for quinoxalines and their metabolites in animal-derived foods, mainly including enzyme-linked immunosorbent assays, fluorescence immunosorbent assays, immunochromatography, and surface plasmon resonance biosensors. In addition, we deeply explored the design of haptens for quinoxalines and their metabolites and analyzed the effect of haptens on antibody performance. This paper aims to provide guidance and references for their accurate and sensitive detection, thereby ensuring food safety and human public health.

Determination of marker residues of quinoxaline-1,4-di-N-oxides and its prototype identification by liquid chromatography tandem mass spectrometry.

Quinoxaline-1,4-di-N-oxides (QdNOs), such as carbadox, olaquindox, mequindox, quinocetone, etc. are a class of antibacterial drugs. Prototype drugs residues can not be detected due to their rapid metabolism in animals. Quinoxaline-2-carboxylic acid (QCA) and 3-methyl-QCA (MQCA) are their common marker residues, so it has been always a challenge to trace the specific QdNOs drug used in food animal production. Herein, a liquid chromatography tandem mass spectrometry method was developed to determine QCA and MQCA, and meanwhile, the prototype drugs were identified by analyzing bis-desoxy QdNOs metabolites in single ion-pair monitoring mode. The method indicated that the average recoveries for QCA and MQCA were from 90 % to 105 % with relative standard deviations below 10 %, and the limits of quantification were 1.0 µg/kg. The limits of detection of five bis-desoxy QdNOs (qualitative markers) reached 0.5 µg/kg. This new analytical strategy can effectively solve the identification problem of QdNOs drugs in animal-derived food.

Multi-class, multi-residue determination of 132 veterinary drugs in milk by magnetic solid-phase extraction based on magnetic hypercrosslinked polystyrene prior to their determination by high-performance liquid chromatography-tandem mass spectrometry.

A quantitative multi-class multi-residue analytical method was developed for the determination of veterinary drugs in milk by high-performance liquid chromatography - tandem mass spectrometry (HPLC-MS/MS). A total of 132 veterinary drugs investigated belonged to almost 15 classes including sulfonamides, ß-lactams, tetracyclines, quinolones, macrolides, nitrofurans, nitroimidazoles, phenicols, lincosamides, pleuromutilins, macrocyclic lactones, quinoxaline antibiotics, benzimidazoles, anthelmintics, coccidiostats and some others. A magnetic solid-phase extraction procedure was developed using magnetic hypercrosslinked polystyrene (HCP/Fe3O4) for the sample preparation prior to HPLC-MS/MS without deproteinization step. The results indicated recoveries of 85-107% for 14 sulfonamides, 85-120% for 13 ß-lactams, 89-115% for 4 tetracyclines, 82-119% for 14 quinolones, 82-115% for 8 macrolides, 97-109% for 4 nitrofurans, 84-115% for 10 nitroimidazoles, 89-114% for 3 phenicols, 86-111% for 3 lincosamides, 97-102% for 2 pleuromutilins, 72-88% for 4 macrocyclic lactones, 87-104% for 4 quinoxaline antibiotics, 76-119% for 21 benzimidazoles, 79-115% for 12 anthelmintics, 81-118% for 12 coccidiostats and 75-119 % for 5 unclassified drugs, with relative standard deviations (RSDs) of less than 20%, and the LOQs ranged from 0.05 to 1 µg kg-1. This methodology was then applied to field-collected real milk samples and trace levels of some veterinary drugs were detected.

Hydrophilic-interaction-based magnetically assisted matrix solid-phase dispersion extraction of carbadox and olaquindox in feeds.

BACKGROUND: Carbadox and olaquindox have been banned from feeds since 1998 by the EU because of their mutagenic, photoallergic, and carcinogenic effects. Unfortunately, owing to their outstanding effect, they are frequently abused or misused in animal husbandry. There is an urgent need to develop a sensitive and reliable method for monitoring these drugs in animal feeds. RESULTS: This work reported a new method of hydrophilic-interaction-based magnetically assisted matrix solid-phase dispersion (MMSPD) extraction coupled with reversed-phase liquid chromatography-mass spectrometry for simultaneous determination of carbadox and olaquindox in animal feeds. 3-Trimethoxysilylpropyl methacrylate (γ-MAPS)-modified attapulgite (ATP) was crosslinked with γ-MAPS-modified iron(II,III) oxide (Fe3 O4 ), 1-vinyl-3-(butyl-4-sulfonate) imidazolium (VBSIm), acrylamide (AM), and N,N'-methylene-bis(acrylamide) (MBA) to synthesize ATP@Fe3 O4 @poly(VBSIm-AM-MBA) particles. The resultant particles were characterized by scanning electron microscopy, energy dispersive spectrometer, transmission electron microscopy, vibrating sample magnetometer, and Fourier transform infrared spectroscopy. Crosslinking of ATP into the magnetic particles has significantly increased the adsorption capacity of the particles. Under optimum conditions, the limits of detection (S/N = 3) were 0.3 µg kg-1 and 0.9 µg kg-1 for carbadox and olaquindox respectively. The intra-day and inter-day recoveries of the spiked targets in feed samples were in the range 83.5-98.3% with relative standard deviations of 1.0-8.3%. CONCLUSION: With a simplified procedure and a low amount of sample, the proposed hydrophilic-interaction-based MMSPD method is not only useful for the determination of carbadox and olaquindox in feeds but also holds great promise for the analysis of other polar targets in solid or semisolid matrices. © 2021 Society of Chemical Industry.

Magnetic ZIF-8-Based Mimic Multi-enzyme System as a Colorimetric Biosensor for Detection of Aryloxyphenoxypropionate Herbicides.

In the present study, a magnetic mimic multi-enzyme system was developed by encapsulating the aryloxyphenoxypropionate (AOPP) herbicide hydrolase QpeH and alcohol oxidase (AOx) in zeolitic imidazolate framework (ZIF-8) nanocrystals with magnetic Fe3O4 nanoparticles (MNPs) to detect AOPP herbicides. The structural, protein loading capacity and loading ratio, porosity, and magnetic properties of QpeH/AOx@mZIF-8 were characterized by scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, thermogravimetric analysis, nitrogen sorption, and vibrating sample magnetometry. An AOPP herbicide colorimetric biosensor made with QpeH/AOx@mZIF-8 had the highest sensitivity toward quizalofop-P-ethyl (QpE) with a limit of detection of 8.2 µM. This system was suitable to detect two other AOPP herbicides, including fenoxaprop-P-ethyl (FpE) and haloxyfop-P-methyl (HpE). The practical application of the biosensor was verified through quantitative analysis of QpE residues in industrial wastewater and field soils. Furthermore, QpeH/AOx@mZIF-8 exhibited excellent long-term storage stability (at least 50 days), easy separation by magnet, and reusability (at least 10 cycles), supporting its promising role in simple and low-cost detection of AOPP herbicides in real environmental samples.

[Determination of quinoxalines veterinary drug residues in food products of animal origin by high performance liquid chromatography-tandem mass spectrometry].

OBJECTIVE: To establish a high performance liquid chromatography-tandem mass spectrometry(HPLC-MS/MS)method for simultaneous determination of olaquindox, quinoxaline-2-carboxylic acid, 3-methyl-quinoxaline-2-carboxylic acid in food products of animal origin. METHODS: Samples were extracted with ethyl acetate-0.1 mol/L sodium dihydrogen phosphate(1∶9, V/V) solution in water bath at 40 ℃, purified by solid phase extraction column(olaquindox uses HLB SPE cartridge, quinoxaline-2-carboxylic acid and 3-methyl-quinoxaline-2-carboxylic acid use MAX SPE cartridge), evaporated by concentrator, and dissolved by mobile phase. The supernatant was separated on Agilent ZORBAX SB-C_(18) column(2.1 mm×50 mm, 1.8 m), using 0.2% formic acid solution methanol solution as mobile phase, and then detected by HPLC-MS/MS using multiple reaction monitoring(MRM) in positive ionization mode. RESULTS: The linear range for olaquindox、quinoxaline-2-carboxylic acid and 3-methyl-quinoxaline-2-carboxylic acid were 2.5-100 µg/L, r & gt; 0.9990.The average recoveries were 72.6%-90.5% and the precisions were 3.2%-13.1%(n=6). The detection limits for olaquindox、quinoxaline-2-carboxylic acid and 3-methyl-quinoxaline-2-carboxylic acid were 0.08 µg/kg. CONCLUSION: The method is specific, sensitive, easy, fast and suitable for the confirmation and quantification of olaquindox、quinoxaline-2-carboxylic acid、3-methyl-quinoxaline-2-carboxylic acid in food products of animal origin.

Simultaneous spectrophotometric quantitative analysis of elbasvir and grazoprevir using assisted chemometric models.

Artificial neural networks and genetic algorithm artificial neural networks, chemometric assisted spectrophotometric models, were developed for the quantitative analysis of elbasvir and grazoprevir in their newly FDA approved pharmaceutical dosage form. The UV absorption spectra of elbasvir and grazoprevir show severe degree of overlap which caused difficulty for selecting certain spectrophotometric method with advantage of simultaneous quantitative analysis of the cited drugs. After extensive study and many experimental trials, artificial neural networks and genetic algorithm artificial neural networks were the suitable models for the quantitative analysis of studied drugs in their binary mixture. Experimental design and constructing the calibration and validation sets of the binary mixture were achieved to implement the proposed models. The models were optimized with the aid of five-levels, two factors experimental design. The designed models were successfully applied to the quantitative analysis of Zepatier® tablets. The results were statistically compared with another reported HPLC quantitative analytical method with no significant difference by applying Student t-test and variance ratio F-test.

Response Surface Methodology of Quantitative of Heterocyclic Aromatic Amines in Fried Fish Using Efficient Microextraction Method Coupled with High-Performance Liquid Chromatography: Central Composite Design.

Meat and meat products are indispensable part of our diet. Heat processing of these tasty foods such as fried fish causes to form heterocyclic aromatic amines (HAAs). The sources of heating have directly affected on the level and type of HAAs. In this research, 2-amino-1-methyl-6-phenylimidazo [4'5-b] pyridine (PhIP), 2-amino-3-methylimidazo [4,5-f]quinolone (IQ), 2-amino-3,4-dimethylimidazo [4,5-f] quinoline (MeIQ) and 2-amino-3,4-dimethylimidazo [4,5-f] quinoxaline (MeIQx) were determined using an efficient analytical methodology coupled with high-performance liquid chromatography. The effective parameters were optimized by central composite design. The results of this survey demonstrated that rang of relative standard deviation were between 4.5 and 8.2, extraction recoveries were obtained 86-97% and limits of detection were between 0.40 and 0.63 for 4 HAAs. The amounts of HAAs found in 20 different fried fish samples were between 0 and 4.8 ng g-1. PhIP with 1.57 ng g-1 and MeIQ with 2.08 ng g-1 have the lowest and highest average level of HAAs, respectively.

Effects of ten vegetable oils on heterocyclic amine profiles in roasted beef patties using UPLC-MS/MS combined with principal component analysis.

Soybean oil (SBO), rapeseed oil (RSO), peanut oil (PO), corn oil (CO), olive oil (OO), sunflower oil (SFO), rice germ oil (RGO), walnut oil (WO), torreya seed oil (TSO), and grapeseed oil (GSO) were used to investigate the formation of heterocyclic amines (HAs) in roasted beef patties. Seven HAs, including 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx), 2-amino-3,4-dimethyl-3H-imidazo[4,5-f]quinolone (MeIQ), 2-amino-3-methyl-3H-imidazo[4,5-f]quinoxaline (IQx), 2-amino-3,4,8-trimethylimidazo[4,5-f]quinoxaline (4,8-DiMeIQx), 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), 1-methyl-9H-pyrido[3,4-b]indole (harman), and 9H-pyrido[3,4-b]indole (norharman) were detected in control patties and patties with vegetable oils. GSO, SFO, and WO greatly reduced the content of PhIP and MeIQ. 1.25%TSO and 3.75% RGO showed higher inhibition effects on the more strongly mutagenic compounds (PhIP, MeIQ, IQx, 4,8-DiMeIQx, MeIQx). SBO, PO, and RSO promoted imidazoquin(ox)aline (MeIQ, MeIQx, 4,8-DiMeIQx, and IQx) and ß-carboline (harman and norharman); 1.25% SBO had the most significant promoting effect on total HA. This could be useful for the reduction of HA by selecting oils during cooking.

A novel magnetic solid-phase extraction method for detection of 14 heterocyclic aromatic amines by UPLC-MS/MS in meat products.

The current study developed a cheap and effective method for the simultaneous extraction of 14 heterocyclic aromatic amines (HAAs) in food matrix. Core-shell Fe3O4@PDA nanoparticles were constructed and acted as the magnetic solid-phase extraction adsorbent to separate and purify HAAs from meat products for the first time. Then, UPLC-MS/MS technique was employed to identify and quantify the HAAs easily. Fe3O4@PDA nanoparticles were synthesized and characterized successfully. Totally 14 HAAs were completely separated in 19.99 min with good regression coefficients. LODs and LOQs were in the range of 0.013-0.247 ng/g and 0.056-0.803 ng/g, respectively. The intra-day precisions and inter-day precisions were below 9%. Except for IQ[4,5-b], Phe-p-1, PhIP, other 11 types of HAAs (DMIP, 1,5,6-TMIP, IQ, IQx, MeIQ, MeIQx, 7,8-DiMeIQx, AαC, MeAαC, Harman, Norharman) could acquire relatively high recoveries (71.06%-108.49%). The proposed method was successfully devoted to the evaluation of HAAs levels in 8 commercial meat products to verify the adaptability.

Residue Behavior and Risk Assessment of Rimsulfuron and Quizalofop-P-ethyl in Potato Under Field Conditions.

A method for simultaneous quantitation of rimsulfuron, quizalofop-P-ethyl and quizalofop-P in potato plant, soil and potato tuber samples was established. The mean recoveries of rimsulfuron, quizalofop-P-ethyl and quizalofop-P in different matrices spiked with them were 81.4%-101.1%, 76.1%-99.0% and 77.4%-106.4% with relative standard deviations (RSDs) of 2.7%-13.3%, 0.9%-5.5%, 1.7%-11.3%, respectively. The open-field trials in China were conducted in potato cultivation system of Changchun and Jinan. The results indicated that the half-lives of rimsulfuron and quizalofop-P-ethyl were 0.04-13.1 days. The residues of quizalofop-P during the harvest time in Jinan soil were < 0.01-0.044 mg kg-1, while there was no residue of target herbicides detected in all other samples. The risk assessment results demonstrated that the risk quotients (RQs) of rimsulfuron and quizalofop-P-ethyl were 7.857 × 10-5 and 8.730 × 10-3, respectively, which exhibited an acceptable dietary risk to Chinese consumers.

Bimetallic Lanthanide-Organic Framework Membranes as a Self-Calibrating Luminescent Sensor for Rapidly Detecting Antibiotics in Water.

Rapid, facile, and reliable recognition of different antibiotics by self-calibrating luminescent sensors are important for practical requirements. Herein, we design and synthesize a series of Eu1-xTbx-MOF using a flexible ligand H4L (5,5'-(propane-1,3-diylbis(oxy))di-isophthalic acid). With changing reactant time, submicrometer bimetallic SMOF-10-10h with homogeneous morphology was achieved and further fabricated MOF-based membrane combining with polymer materials. A luminescent study indicated that the bimetallic SMOF-10-10h membrane possesses a legible emission peak for Eu3+ and Tb3+ ions, which can act as a self-calibrating luminescent probe for efficiently sensing different antibiotics within a certain concentration range through two-dimensional (2D) readouts based on the emission intensity ratio. Our work first reports an inexpensive and convenience bimetallic MOF-based membrane as a luminescent sensor with self-calibrating to detect various antibiotics, which makes it a potential luminescent sensor for beneficial application.

A Photoaffinity-Based Fragment-Screening Platform for Efficient Identification of Protein Ligands.

Advances in genomic analyses enable the identification of new proteins that are associated with disease. To validate these targets, tool molecules are required to demonstrate that a ligand can have a disease-modifying effect. Currently, as tools are reported for only a fraction of the proteome, platforms for ligand discovery are essential to leverage insights from genomic analyses. Fragment screening offers an efficient approach to explore chemical space. Presented here is a fragment-screening platform, termed PhABits (PhotoAffinity Bits), which utilizes a library of photoreactive fragments to covalently capture fragment-protein interactions. Hits can be profiled to determine potency and the site of crosslinking, and subsequently developed as reporters in a competitive displacement assay to identify novel hit matter. The PhABit platform is envisioned to be widely applicable to novel protein targets, identifying starting points in the development of therapeutics.

Simultaneous determination of olaquindox, oxytetracycline and chlorotetracycline in feeds by high performance liquid chromatography with ultraviolet and fluorescence detection adopting online synchronous derivation and separation.

Olaquindox, oxytetracycline and chlorotetracycline were widely used in feed as antibiotics and growth promoter to improve feed conversion efficiency and increase the rate of weight gain for animals. However, the use of these antibiotics in feed was gradually prohibited because of concerns about contamination and resistance in animals. A quantitative and confirmatory method for determining the presence of olaquindox, oxytetracycline and chlorotetracycline in feed by high performance liquid chromatography equipped with ultraviolet detector in series with fluorescence detector (HPLC-UVD-FLD) was developed, optimized, and validated in three different matrices (compound, concentrated and premix feed). The analytes extraction was performed with a mixture of acetonitrile and 0.1 mol/L ethylenediamine tetraacetic acid disodium-Mcllvaine buffer (1:4, v/v) by one step sample preparation procedure. The validated method presented a broad linear range and good linearity with weighted least square method. The decision limit of the analytes ranged from 0.61 to 0.77 mg/kg for olaquindox, 0.90 to 1.2 mg/kg for oxytetracycline and 1.3 to 2.0 mg/kg for chlorotetracycline. The average recovery values found in intermediate precision conditions were ranged from 88.0 to 99.7% for olaquindox with RSD lower than 11.1%, from 84.4 to 99.0% for oxytetracycline with RSD lower than 9.6%, from 83.8 to 97.5% for chlorotetracycline with RSD lower than 10.0%. By Youden test and bottom-up method, the method was proved to be sufficiently robust and had a small uncertainty for different concentration levels. The developed method was successfully utilized for commercial feed samples to monitor complex cross contamination and residue conditions. Online synchronous derivation and separation using ultraviolet detector in series with fluorescence detector can effectively prevent false positive of chlorotetracycline in feed caused by vegetable meal. Since olaquindox, oxytetracycline and chlorotetracycline are widely used in feed, the developed method provide an important and analytical tool for the simultaneous identification and quantification of them in feed to monitor its risk of cross contamination and excessive content.

Determination of 3-Methyl-quinoxaline-2-carboxylic Acid and Quinoxaline-2-carboxylic Acid in Pork Based on a Background Fluorescence Quenching Immunochromatographic Assay.

A novel rapid method based on a background fluorescence quenching immunochromatographic assay (bFQICA) was established to achieve simultaneously the quantitative detection of 3-methyl-quinoxaline-2-carboxylic acid (MQCA) and quinoxaline-2-carboxylic acid (QCA), which were efficiently extracted and enriched 4 times using immunomagnetic beads from pork. The analysis of field pork samples by bFQICA was in accordance with that of LC-MS/MS; especially, the proposed bFQICA exhibited great advantages in convenience and efficiency, which only takes 30 min for the detection of MQCA and QCA.

Effect of pH on the Hydrolytic Transformation of a New Mixture Formulation of Fomesafen and Quizalofop-ethyl in Water.

A hydrolytic transformation study was conducted in water of pH 4.0, 7.0 and 9.2 to evaluate the effect of pH on persistence of a new readymix formulation of fomesafen and quizalofop-ethyl. The water samples were fortified at 0.5 and 1 µg mL-1 levels and analysed at 0 (2 h), 1, 3, 7, 15, 30, 60, 90, 120, 150 days interval. Both the analytical methods were validated following SANTE guideline and found accurate based on average recovery of 80-100%, Relative standard deviation (RSD) < 20% and Coefficient of Determination (R2) 0.99. The dissipation of both the molecules was pH dependent and followed first order kinetics. Higher persistence of fomesafen was observed in alkaline pH as compared to neutral and acidic pH with half-life of 41.56-63.24 days, whereas higher stability of quizalofop-ethyl was observed in the water of acidic pH followed by neutral and alkaline pH with half-life of 1.26-8.09 days.

Surface plasmon resonance biosensor for the determination of 3-methyl-quinoxaline-2-carboxylic acid, the marker residue of olaquindox, in swine tissues.

To monitor the illegal use of olaquindox in animals, a monoclonal antibody-based surface plasmon resonance (SPR) biosensor method has been developed to detect 3-methyl-quinoxaline-2-carboxylic acid, the marker residues of olaquindox, in swine tissues. The limit of detection was 1.4 µg kg-1 in swine muscle and 2.7 µg kg-1 in swine liver, which are lower than the EU recommended concentration (10 µg kg-1). The recoveries were from 82% to 104.6%, with coefficients of variation of less than 12.2%. Good correlations between SPR and HPLC results (r = 0.9806, muscle; r = 0.9698, liver) and between SPR and ic-ELISA results (r = 0.9918, muscle; r = 0.9873, liver) were observed in the affected tissues, which demonstrated the reliability of the SPR method. This method would be a rapid and reliable tool for the screening of the residues of olaquindox in the edible tissues of animals.

Molecularly imprinted electrochemical sensor based on polypyrrole/dopamine@graphene incorporated with surface molecularly imprinted polymers thin film for recognition of olaquindox.

In this paper, an advanced molecularly imprinted electrochemical sensor (MIECS) based on electropolymerized olaquindox (OLA) surface molecularly imprinted polymer thin film on a modified glassy carbon electrode (GCE) was developed for the detection of OLA. It was fabricated by coating dopamine@graphene (DGr) on GCE, then electropolymerizing pyrrole (Py) and molecularly imprinted polymers (MIPs). Graphene (Gr) was introduced for improving conductivity and sensitivity. Dopamine (DA) was used for dispersion and adhesion of Gr. Polypyrrole (PPy) could fix DGr and enhance the current response evidently. The established sensor could selectively recognize OLA but not the analogs of OLA. Some essential parameters controlling the performance of the developed sensor were investigated and optimized. Under optimal conditions, the linear relationship between the current intensity and OLA concentration was obtained from 50 nmol L-1 to 500 nmol L-1 with a limit of detection (LOD) of 7.5 nmol L-1. Analytical results of OLA based on the developed MIECS for fish and feedstuffs showed a good agreement with the results based on high performance liquid chromatography (HPLC).

Development of a Sensitive Chemiluminescent Immunoassay for the Determination of 3-Methyl-quinoxaline-2-carboxylic Acid and Quinoxaline-2-carboxylic Acid in Edible Animal Tissues Using Immunomagnetic Beads Capturing.

We have reported a sensitive chemiluminescent competitive indirect enzyme-linked immunosorbent assay (CL-ciELISA) based on immunomagnetic beads separation, purification and enrichment for the simultaneous determination of 3-methyl-quinoxaline-2-carboxylic acid (MQCA) and quinoxaline-2-carboxylic acid (QCA) in edible animal tissues. Forty field samples were analyzed with the developed CL-ciELISA, and the results correlated well with those obtained in liquid chromatography-tandem mass spectrometry (LC-MS/MS), confirming the utility of CL-ciELISA for the quantitation of MQCA and QCA in fish, shrimp, pork and chicken with a good accuracy.