Identification of Moringa oleifera protein responsible for the decolorization and pesticide removal from drinking water and industrial effluent – an in silico and in situ evaluation

Natural products are always in demand, especially in the food and water treatment industry, to reduce health hazards caused by the prolonged use of chemicals. Though crude seed extract of Moringa oleifera (MOCE) is used for decolouration, the protein responsible for such activity is not fully known. In this study, in silico analysis of Moringa oleifera coagulant protein (MOCP; a predominant oligomeric protein in MOCE) was undertaken to check its molecular interactions with water and soil pollutants, in order to identify the protein accountable for such activities. The molecular docking studies of MOCP with azo dyes like congo red, tartrazine) and a pesticide (dichlorodiphenyltrichloroethane) revealed a strong binding affinity (?5.66, ?5.33 and ?5.04, respectively, kJ mol^?1) between the protein and the pollutants through hydrogen bonding and electrostatic interactions. Further, these results were verified in situ with MOCP, a recombinant form of MOCP (MOCRP) and MOCE against congo red (100 mg L^?1) and revealed the dye removal efficiency of 63.8%, 65.7%, and 72.3%, respectively. While the jar test results of synthetic coloured water and industrial textile effluent containing congo red showed 51.6% and 58.3%. Hence, we believe that the MOCP is responsible for multiple activities of MOCE and suggest its prospective use for large‐scale treatment of drinking water and industrial effluents. © 2014 Society of Chemical Industry     

哈尔滨郊区池塘养殖鱼类六六六和滴滴涕残留特征及食用健康风险

目的 明确哈尔滨郊区池塘养殖鱼类六六六(HCHs)和滴滴涕(DDTs)的残留水平及食用安全性。方法 以4种养殖鱼类(鲤、鲢、鲶和草鱼)为研究对象,采用气相色谱-串联质谱法(gas chromatography-tandem mass spectrometry, GC-MS)分析了49份鱼类样品的背肌、腹肌、肝脏、皮和鳃中HCHs和DDTs的残留水平,并对其可食部分进行致癌与非致癌风险评价。结果 HCHs和DDTs在鱼体各组织中残留量分别为0.299~12.881 μg/kg和0.012~1.439 μg/kg,均低于GB 2763—2021《食品安全国家标准 食品中农药最大残留限量》中规定的限量标准(DDTs≤500 μg/kg和HCHs≤100 μg/kg)。在背肌、腹肌和皮中,HCHs和DDTs残留量最高的均是鲶,鲢最低,而且背肌残留水平高于腹肌,HCHs的残留量大于DDTs。鱼体中残留的HCHs异构体组成以γ-六六六为主,贡献率在80.24%~95.82%,其次是α-六六六。食用该养殖鱼类导致的HCHs和DDTs每日摄入量分别为3.433~10.751 ng/(kg·d)和0.213~1.420 ng/(kg·d),均低于参考剂量(reference dose, RfD),致癌风险指数(carcinogenic risk index, CRI)在10-7~10-5,存在一定的潜在致癌风险;非致癌风险指数(non-carcinogenic hazard index, HI)均小于1,在可接受水平。结论 尽管HCHs和DDTs已被禁用多年,仍可在养殖鱼类体内检测到,但其残留水平低于国家限量标准,对人群无明显的食用健康风险。     

气相色谱——三重四极杆质谱法测定食用植物油中57种有机污染物

目的:建立高通量测定食用植物油中57种有机污染物的分析方法。方法:样品中的目标物通过乙腈—正己烷溶液提取，经分散固相萃取法与固相萃取净化法净化，采用气相色谱—三重四极杆质谱法测定食用油中16种多环芳烃、17种邻苯二甲酸酯、8种有机氯和16种多氯联苯的含量。结果:所检测的目标物在0.001～0.1μg/mL的质量浓度范围内呈良好的线性关系(r²>0.998),检出限为0.16～2.0μg/kg,基质加标平均回收率为71.0%～119.5%,相对标准偏差≤12.6%(n=6)。采用此方法对24批市售的食用油进行检测，其中25种目标物在样品中有检出。结论:该方法高效、准确、高灵敏度，对持久性有机污染物与邻苯二甲酸酯在食用油中的监测有着重要意义。