Propamocarb is a carbamate fungicide used to control Phytophthora disease. Frequent and large-scale use of pmpamocarb means that it poses a potential threat to the health of consumers. Monoclonal antibodies against pmpamocarb were prepared using a hapten of propamocarb that was generated by introducing a benzene ring and a carboxyl group into the structure of propamocarb. A lateral flow immunoassay strip was developed for the detection of pmpamocarb in tomato and cucumber samples using the gold nanoparticle-labeled antibody. The immunoassay strip was found to provide a visible limit of detection was 5 ng/g and the cut-off value was 250 ng/g for propamocarb in food samples. For quantitative analysis, the calculated limits of detection (LODs) of the immunoassay strip were 1.43 ng/g and 0.44 ng/g in cucumber and tomato, respectively. Using the immunoassay strip, the average recoveries ranged from 95.5 +/- 5.4% to 108.8 +/- 6.8%, with CVs of 3.1-6.2% for the cucumber, and the average recoveries were 95.1 +/- 6.5%-111.9 +/- 4.2%, with CVs ranging from 3.7% to 6.8% for tomato samples. All the results demonstrated that the immunoassay strip was suitable for the detection of propamocarb in fruits and vegetables.

An improved gas chromatography-based analytical method for the simultaneous separation of seventy-two fatty acids was developed. Twenty-six types of trans fatty acids and conjugated linoleic acids were separated and identified with this method, especially trans C18 isomers. This method was confirmed to be high throughput and have high sensitivity and a low detection limit. It was successfully applied to separate and identify fatty acids in fresh basil seed oil. The linolenic acid content (51.67 g/100 g) was highest in basil seed oil, followed by linoleic acid (20.16 g/100 g) and oleic acid (12.70 g/100 g). These unsaturated fatty acids in fresh basil seed oil were transformed into trans fatty acids, conjugated linoleic acids and saturated fatty acids after heating to a certain temperature for an adequate duration, and the formation mechanisms were characterised.

重金属污染、农药残留问题、真菌毒素超标、加工危害物产生等是粮油食品供应链中安全问题集中爆发的几个主要方面。本课题已建立粮油食品供应链中危害物快速预处理及精准识别技术15种：电热蒸发—原子荧光检测及高灵敏X射线荧光光谱识别技术的建立，简化了粮油食品重金属检测消解的预处理程序，检测周期从6-8h缩短至15min以内；改良QuEChERS前处理方法结合UPLC-MS/MS检测，实现大豆及豆制品中78种除草剂多残留同时精准识别；构建了赭曲霉毒素、桔霉素等真菌毒素的ELISA快速精准识别技术，金标试纸条检测范围最低可达0.21μg/kg;建立C3-C24系列脂肪酸气相色谱识别方法，脂肪酸同时检测种类从37种增加到72种。探讨粮油食品供应链中的危害物的迁移、转化规律及调控机理：优化糙米去砷加工工艺，去除率达32%-43%;明确豆制品中禾草灵、多菌灵、马拉硫磷等多农药残留行为规律，建立农残加工因子的风险评估新思路；阐明油酸、亚油酸和亚麻酸直接异构化反应途径及反应机理。构建了粮油食品供应链危害物指纹图谱数据库及农药残留加工因子数据库的基本架构，确定了危害物和潜在风险因子的法规标准、基本信息、指纹图谱库、检测结构分析、基础地理信息等多个功能模块，完成危害物性质基础数据百余条及指纹图谱数据百余条的信息采集。 Heavy metal pollution,pesticide residues,excessive mycotoxins and hazardous substances from processing are the main points of the safety problems in the supply chain of cereal and oil food.This project has established 15 technologies for rapid pretreatment and identification of hazardous substances in the cereal and oil food supply chain.Methods for heave metal detecting were established by the electrothermal vaporization-atomic fluorescence spectrometry and the highly sensitive X-ray fluorescence spectroscopy respectively,which were simplified the pretreatment procedures such as digestion.The detection cycle was shortened from 6-8 h to less than 15 min.A method for the analysis of 78 herbicide residues in soybean and its products was developed using the modified QuEChERS pretreatment and ultra performance liquid chromatography coupled with triple quadrupole mass spectrometry(UPLC-MS/MS).Ochratoxin A(OTA)and citrinin(CIT)could be identified by ELISA quickly and precisely,the detection range of gold standard test strips was as low as 0.21μg/kg.Identification method of C3-C24 series fatty acid were established by gas chromatography,and the types of fatty acid detection increased from 37 to 72. The migration,transformation rule and regulation mechanism of hazardous substances were discussed in the supply chain of cereal and oil products.The arsenic removal processing technology of brown rice was optimized,and the removal rate could reach to 32%-43%.Clarify the behavioral patterns of multi-pesticide residues such as Promethazine,Carbendazim and Malathion etc in soy products,and the new ideas for risk assessment by processing factors of pesticide residue.The isomerization reaction pathway and mechanism of oleic acid,linoleic acid and linolenic acid were elucidated.The basic structure of the fingerprint database for hazardous substances in the supply chain of cereal and oil products and processing factors of pesticide residues database was separately constructed.Several functional modules were determined for hazardous substances and potential risk factors,such as regulatory standards,basic information,fingerprint database,analysis of detection results and basic geographic information.More than 100 basic data on the nature of hazards and fingerprint data had been collected.

粮油食品供应链长，基质复杂，污染环节多，极易形成多种风险隐患。构建“危害物非靶向筛查”的防控迁移安全技术保障体系，必须建立在粮油食品供应链中多危害物的高通量、高灵敏的精准识别技术上。本报告针对粮油食品供应链中主要危害物重金属、农药残留、真菌毒素、反式脂肪酸在不同基质下的精准识别展开研究。建立校准了谷物基中汞元素的电热蒸发—原子荧光检测技术，降低了由于传统消解过程中汞蒸发导致的数据偏差；建立了豆制品(豆腐)加工过程中的异恶草松、氟磺胺草醚、精喹禾灵及其代谢物精喹禾灵(酸)等除草剂的HPLC-MS/MS精准识别技术，同时明确了研磨、过滤等加工控制的关键控制点；建立了反式亚油酸和共轭亚油酸异构体的精准识别技术，明确了植物油热质加工过程中3种反式亚油酸和20种共轭亚油酸的生成变化规律，并提出了各产物的异构途径；构建了赭曲霉毒素、桔霉素的ELISA快速精准识别技术，并对其中使用的合成赭曲霉毒素(OTA)、桔霉素(CIT)完全抗原进行了表征和鉴定。通过亚克隆实验筛选出单克隆抗体1G1和1F2。利用单克隆抗体1G1和1F2对ic-ELISA进行优化，确定了单克隆抗体最佳工作点。基于粮油食品危害物精准识别技术的研究基础，初步构建了粮油食品供应链危害物指纹图谱数据库的基本架构。确定了危害物和潜在风险因子的法规标准、基本信息、指纹图谱库、检测结构分析、基础地理信息等多个功能模块。 Because the supply chain of cereal and oil food is very long,and complicated,many hazardous pollutants are easily appeared harming food processing.High-throughput,highly sensitive,and highly accurate identification technologies for multiple hazards detection are the premise for the establishment of a safety technology system of prevention,control and migration of hazards in the cereal and oil food supply chains,based on the“non-targeted screening of hazardous materials”.This study focus on the accurate identification of the major hazardous pollutants(heavy metals,pesticide residues,mycotoxins,trans fatty acids)of different food materials in the cereal and oil food supply chain.We have established and calibrated the Electrothermal Evaporation-Atomic Fluorescence Detection Technology for mercury detection in cereals,reduced data bias due to mercury evaporation during traditional sample digestion process;Established HPLC-MS/MS precision identification technology for herbicides such as clomazone,fomesafen,quizalofop-p-ethyl and its metabolite quizalofop acid in the processing of soy products(tofu).And the critical control points in the grinding,filtration and other processing were clarified.Established the accurate identification techniques for trans-linoleic acid and conjugated linoleic acid isomers.Revealed the rule of the formation and transformation of three trans-linoleic acids and 20 conjugated linoleic acids during the thermal processing of vegetable oils,and the heterogeneous pathways of these products were proposed.Established a fast and accurate ELISA identification technique for ochratoxin and citrinin,and the synthetic ochratoxin A(OTA)and citrinin(CIT)complete antigens in it were characterized and identified.Monoclonal antibodies 1G1 and 1F2 were screened by subcloning experiments.The ic-ELISA was optimized with monoclonal antibodies 1G1 and 1F2,the best working point for monoclonal antibodies were determined.Based on the preliminary research of the accurate identification of hazardous substances in cereal and oil food,we have initially constructed the basic framework of the fingerprint database of the main hazards in the cereal and oil food supply chain.Multiple functional modules on hazards and potential risk factors were identified,such as regulatory standards,basic information,fingerprint libraries,structural detection analysis,basic geographic information,etc.

An anti-rosiglitazone (RSG) monoclonal antibody (4G6) was prepared to develop an immunochromatographic strip for the detection of illicitly added RSG in hypoglycemic functional foods. The monoclonal antibody was highly specific for RSG, with a half-life inhibitory concentration (IC50) of 1.0889 ng mL-1. Its limit of detection was 0.2178 ng mL-1 with a linear detection range of 0.2178-1.742 ng mL-1. The cut-off values of colloidal gold-based immunochromatographic test strips in phosphate buffered saline and functional food samples were both 10 ng mL-1. In the spiked samples and recovery tests, the recovery ranged from 96.58% to 101.68%. The results obtained by the immunochromatographic assay were consistent with those obtained by indirect competitive-ELISA. Therefore, our developed immunochromatographic strip system is suitable for the on-site detection and rapid screening of RSG in food samples. © 2019 The Royal Society of Chemistry.

The toxicity of aristolochic acids (AAs) in traditional Chinese medicine has recently caused widespread concern worldwide. In this study, we developed a gold nanoparticle (GNP) immunochromatographic assay (ICA) for the rapid detection of AA I in herbs. Firstly, by the method of immunization and cell fusion, we screened a highly specific and sensitive monoclonal antibody (2A8), which has a half-maximum inhibition concentration of 5.02 ng/ml. On this basis, we developed a lateral-flow ICA strip, having a visual limit of detection and a cut-off limit of 0.25 mu g/g and 0.5 mu g/g respectively. The results from this could be obtained within 5 min using the naked eye. Therefore, the ICA is suitable for the on-site detection and mass screening of AA ROMAN NUMERAL ONE in herbs.

Praziquantel (PZQ) is a broad-spectrum antiparasitic drug used in mammals and fish. In this study, we developed an indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) for the detection of PZQ residues. The hapten PZQ-HS produced by introducing an amino group at a benzene ring synthesized the immunogen and the coating antigen with carrier proteins. Highly sensitive monoclonal antibodies (mAbs) were prepared following mouse immunization and cell fusion. Under optimum conditions, the half maximal inhibitory concentration of the cell line 4E9 was 7.4 ng/mL, and the working range was 2.4-22.8 ng/mL. Immunochromatographic strips (ICS) were developed for the rapid detection of PZQ residues in mackerel. The reliability of the ICS assay was verified with PZQ-negative mackerel and confirmed by HPLC/MS. The cutoff value for ICS was 50 ng/mL PZQ. Our findings revealed that ic-ELISA and ICS can be used for the rapid detection of PZQ in mackerel.[GRAPHICS].