食品中氟虫腈及其代谢物残留与检测研究进展

氟虫腈是一类广谱杀虫剂,通过与害虫等无脊椎动物神经中枢细胞膜上的γ-氨基丁酸受体结合,造成其神经功能受损,从而引起死亡,对主要农作物的害虫都有良好的防治效果,被广泛应用于农业、兽医等领域。但因其不仅对害虫有危害,对某些哺乳动物也存在毒性,故我国于2009年禁止氟虫腈作为农药使用。氟虫腈通过对土壤、水体等环境造成严重污染,从而对动植物体造成伤害,最终随着动植物食品进入身体威胁人类健康。本文主要列举了近5年国内外食品中氟虫腈及其代谢物污染现状,概述了测定食品中氟虫腈及其代谢物的前处理方法及检测方法的最新进展,对食品中氟虫腈及其代谢物的后续研究提出建议,为未来食品中农药和药物残留的控制提供参考。     

氟虫腈的危害及检测技术研究进展

食品生产是一个系统工程,涉及到产地环境、种植过程、养殖过程、产品加工、货物流通、贮存及货架存放等各个环节,因此影响因素复杂多样。其中农药残留是影响食品安全的重要因素之一。氟虫腈是一种广谱杀虫剂,在作物害虫控制、家庭宠物寄生虫防控、娱乐场所环境卫生改善等各方面得到广泛应用。然而,氟虫腈残留对水体、土壤及环境造成严重污染,从而损害了有益生物的生理健康乃至威胁到其生命安全,并最终通过食物链危害到人类健康和安全。2017年,欧洲爆发了由氟虫腈引起的毒鸡蛋事件,该事件爆发凸显出做好氟虫腈监控检测工作的重要性。本文综述了氟虫腈的应用、残留危害及监控检测方法研究进展,并展望了其检测新技术未来发展趋势。     

氟虫腈检测技术及国内外标准制定研究进展

氟虫腈是世界上首个苯基吡唑类高活性广谱性杀虫剂, 具有独特的杀虫机制, 曾在农药界具有十分良好的应用前景。欧洲爆发的由氟虫腈引起的毒鸡蛋事件却让全球知晓了氟虫腈同样具有污染自然环境、影响人类健康和安全的危害, 并凸显出做好氟虫腈监控检测工作的重要性。世界各国政府和相关组织都对氟虫腈在基质中的最大残留限量做了严格规定,并研究开发出具有不同特点的检测技术。。本文综述了氟虫腈的特性作用、残留危害、国内外限量值的规定和监控检测的研究方法, 介绍了氟虫腈在国际标准化组织ISO(International Organization for Standardization, ISO)体系中相关标准建立的意义和进展, , 并展望了我国旨在通过ISO国际标准的制订，推动全球食品安全检测技术的进步，加强各国在食品安全问题的合作，从而提高我国在国际食品安全事宜上的话语权和影响力, 推动中国相关产业的全球化贸易发展。     

QuEChERS-高效液相色谱-串联质谱法测定稻田水产品中氟虫腈及其代谢物残留

以QuEChERS作为样品前处理方法,结合高效液相色谱-串联质谱技术建立检测稻田水产品中氟虫腈及其代谢物氟甲腈、氟虫腈砜、氟虫腈亚砜残留的方法。样品通过体积分数为0.10%甲酸-乙腈溶液及陶瓷均质子旋涡振荡法提取,由0.15 g乙二胺?N?丙基硅烷分散萃取净化后采用ZORBAX Extend-C18色谱柱（2.1 mm×100.0 mm,1.8 μm）进行分离,电喷雾负离子模式测定,基质匹配标准曲线后运用外标法定量。结果表明,稻田水产品中氟虫腈、氟甲腈、氟虫腈砜和氟虫腈亚砜的平均回收率在85.2%～112.6%之间,相对标准偏差在1.2%～12.4%之间,氟虫腈及其代谢物在质量浓度0.5～100.0 ng/mL之间线性良好,相关系数均大于0.999,检出限为1.0～1.5 μg/kg、定量限为3.0～5.0 μg/kg,二者均低于GB 2763—2019《食品中农药最大残留限量》对禽肉中氟虫腈最大残留限量10 μg/kg的规定,实验方法简单、快速、灵敏,能够满足稻田水产品中氟虫腈及其代谢物的检测需求。     

鸡蛋中氟虫腈及其代谢物残留分析方法

采用超高效液相色谱-串联质谱技术,以鸡蛋为研究对象,建立一种高效测定鸡蛋中氟虫腈及其代谢物残留测定方法。样品用乙腈提取,并通过固相萃取技术对样品进行净化处理,供超高效液相色谱-串联质谱仪进行检测。实验结果表明,该方法能够有效地分离和测定氟虫腈及其代谢物残留。在3 个不同的添加水平（0.005、0.010、0.020 mg/kg）下,4 种农药的回收率范围为81.3%～92.5%,相对标准偏差均低于5.5%。;在0.001～0.050 μg/mL 浓度范围内,线性关系良好,相关系数均大于0.990 4;氟虫腈、氟甲腈、氟虫腈砜与氟虫腈亚砜的检出限分别为0.001、0.002、0.002、0.002 mg/kg。该方法准确、灵敏、快速,可满足对鸡蛋中氟虫腈、氟甲腈、氟虫腈砜与氟虫腈亚砜4 种药物残留的检测需要。     

叶面肥对烟叶中4种杀虫剂残留降解的影响

叶面肥与农药混用是农业生产中一种新兴的药肥施用模式,但其对农药残留的影响尚待进一步研究。本试验开展了叶面肥与农药不同施用模式试验,采用QuEChERS和高效液相色谱-串联质谱(HPLC-MS/MS)相结合的检测方法,探讨叶面肥对烟叶中氯虫苯甲酰胺、氟啶虫酰胺、氟苯虫酰胺和氟啶虫胺腈4种杀虫剂残留降解速率的影响。结果表明,施用叶面肥对氯虫苯甲酰胺残留降解促进作用显著,对氟啶虫酰胺、氟苯虫酰胺和氟啶虫胺腈残留降解有一定促进作用,且叶面肥稀释1000倍处理效果最佳。研究结果为"药肥合一"模式降低烟叶农药残留水平,提高烟叶品质提供基础数据。     

GC-MS法测定芹菜中氟虫腈及其代谢物的残留量

建立同时检测芹菜中氟甲腈、氟虫腈硫醚、氟虫腈、氟虫腈砜4种农药残留的气质联用检测方法。样品经乙腈提取后,浓缩过石墨化炭黑/氨基固相萃取柱净化,洗脱液洗脱浓缩定容后检测。4种农药在0.01 mg/L~1.0 mg/L范围内线性关系良好(R≥0.999 2),平均回收率为82.9%~102.2%,精密度为2.18%~5.66%,均满足定量分析的要求。4种农药残留的定量限为0.002 mg/kg。     

QuEChERS-液质联用法测定禽源性食品中苯基吡唑类杀虫剂残留

本方法建立了一种QuEChERS-液质联用法同时检测禽源性食品中氟虫腈、氟甲腈、氟虫腈砜、氟虫腈亚砜、乙虫腈、丁烯氟虫腈共6种苯基吡唑类杀虫剂残留的方法。样品采用乙腈提取、QuEChERS方法净化,质谱采集模式为ESI-negative--MRM。结果表明,6种苯基咪唑类杀虫剂在不同基质中的定量限不同,定量限范围为0.06~1.20 μg/kg,在不同线性范围(1~40、4~160、10~400 μg/kg)下相关性良好(R2>0.994)。考虑三类样品基质的区别,分别进行3种水平的标准添加测试,回收率达84.49%~107.86%,相对标准偏差为0.99%~4.19%。该方法快速、灵敏、准确,适合用于禽源性食品中苯基咪唑类杀虫剂残留量的测定。     

烹饪方法对鸡蛋及鸡肉中氟虫腈及其代谢物残留量的影响

建立鸡蛋及鸡肉中氟虫腈及其代谢物氟甲腈、氟虫腈砜、氟虫腈亚砜的超高效液相色谱-串联质谱定量检 测方法。采用乙腈沉淀蛋白,并用QuEChERS处理样本后进样分析。结果表明,4 种目标化合物的平均加标回收率 在75.7%～104.5%之间,相对标准偏差在1.3%～10.4%之间。利用此方法对高、低2 个浓度的被污染样本烹调前后的 氟虫腈及其代谢物含量进行检测。分别采用蒸锅中蒸制10 min、平底锅中小火煎制5 min及沸水中煮制10 min的烹调 方法对鸡蛋和鸡肉阳性样本进行烹调,氟虫腈砜的含量在鸡蛋和鸡肉烹调前后没有发生较大变化,在氟虫腈砜含量 变化最大的煎制法处理之后,鸡蛋中的氟虫腈砜含量也只降低了12.2%和16.2%,鸡肉中只降低了7.3%和14.7%。结 果表明,烹调并不会使鸡蛋和鸡肉中氟虫腈及其代谢物的含量发生明显变化,加强源头管控是最有效的监管方法。     

气相色谱-负化学源-串联质谱法测定动物源食品中氟虫腈及其4种代谢产物残留量

建立动物源食品(鸡蛋、鸡肉、鸡肝)中氟虫腈及其4种代谢产物(氟甲腈、氟虫腈砜、氟虫腈硫醚、酰胺氟虫腈)残留量的气相色谱-负化学源-串联质谱(gas chromatography-negative chemical ionization-tandem mass spectrometry,GC-NCI-MS/MS)测定方法。样品经乙腈(正己烷饱和)提取后,采用改进的QuEChERS净化和GC-NCI-MS/MS的多反应监测模式检测,基质匹配工作曲线法定量。实验结果表明,氟虫腈及其4种代谢产物在1~100μg/L质量浓度范围内线性良好,线性系数均大于0.999 0,氟甲腈、氟虫腈和氟虫腈硫醚定量限(RSN≥10)为0.5μg/kg,氟虫腈砜和酰胺氟虫腈定量限为1.0μg/kg。在2.0、10.0、20.0μg/kg加标水平下,回收率在80.2%~108.7%之间,相对标准偏差为3.8%~10.2%。该方法灵敏度高、准确性好,能够满足动物源食品中氟虫腈及其4种代谢产物残留量的测定。     

Occurrence of fipronil and its biologically active derivatives in urban residential runoff

Insecticides are commonly used around homes for controlling insects such as ants, termites, and spiders. Such uses have been linked to pesticide contamination and toxicity in urban aquatic ecosystems. Fipronil is a relatively new and popular urban-use insecticide that has acute toxicity to arthropods at low-ppb levels. In this study, we collected runoff water from 6 large communities, each consisting of 152 to 460 single-family homes, in Sacramento County and Orange County, California, and evaluated the occurrence of fipronil and its biologically active derivatives over 26 months under dry weather conditions. Statistical modeling showed that the levels of fipronil and derivatives in the runoff water were both spatially and temporally correlated. More than 10-fold differences were observed between the Sacramento and Orange County sites, with the much higher levels for Orange County (southern California) coinciding with heavier use. The median concentrations of combined fipronil and derivatives for the Orange County sites were 204-440 ng L(-1), with the 90th percentile levels ranging from 340 to 1170 ng L(-1). These levels frequently exceeded the LC50 values for arthropods such as mysid shrimp and grass shrimp. The highest levels occurred from April to October, while decreases were seen from October to December and from January to March, likely reflecting seasonal use patterns and the effect of rain-induced washoff. Fipronil and fipronil sulfone (oxidation derivative) each accounted for about 35% of the total concentrations, with desulfinyl fipronil (a photolytic product) contributing about 25%. Results of this study clearly established residential drainage as a direct source for pesticide contamination in urban waterways, and for the first time, identified fipronil as a new and widespread contaminant with potential ecotoxicological significance.     

食品中氯虫苯甲酰胺分析方法研究进展

氯虫苯甲酰胺是美国杜邦公司开发的新型邻甲酰氨基苯甲酰胺类杀虫剂,具有杀虫谱广、速效性好、持效期长的特点,在蔬菜、瓜果、水稻等作物上广泛使用。该药对人体健康具有潜在危害性,许多国家对其残留限量做出明确规定。为满足不同氯虫苯甲酰胺限量的检测要求,发展简单、快速、灵敏、可靠的检测方法尤为重要。本文综述了近年来国内外食品中氯虫苯甲酰胺的主要检测技术及其研究进展,包括固相萃取、分散固相萃取等样品前处理方法,以及液相色谱、液相色谱-质谱联用等分析方法,以期为今后食品中氯虫苯甲酰胺的分析研究提供参考。     

Phototransformation of the insecticide fipronil: identification of novel photoproducts and evidence for an alternative pathway of photodegradation

Fipronil is a recently discovered insecticide of the phenylpyrazole series. It has a highly selective biochemical mode of action, which has led to its use in a large number of important agronomical, household, and veterinary applications. Previous studies have shown that, during exposure to light, fipronil is converted into a desulfurated derivative (desulfinyl-fipronil), which has slightly reduced insecticidal activity. In this study, the photodegradation of fipronil was studied in solution at low light intensities (sunlight or UV lamp). In addition to desulfinyl-fipronil, a large number of minor photoproducts were observed, including diversely substituted phenylpyrazole derivatives and aniline derivatives that had lost the pyrazole ring. Desulfinylfipronil itself was shown to be relatively stable under both UV light and sunlight, with only limited changes occurring in the substitution of the aromatic ring. Since this compound accumulated to levels corresponding to only 30-55% of the amount of fipronil degraded, it was concluded that one or more alternative pathways of photodegradation must be operating. On the basis of the structurally identified photoproducts, it is proposed that fipronil photodegradation occurs via at least two distinct pathways, one of which involves desulfuration at the 4-position of the pyrazole ring giving the desulfinyl derivative and the other of which involves a different modification of the 4-substituent, leading to cleavage of the pyrazole ring and the formation of aniline derivatives. The latter compounds do not accumulate to high levels and may, therefore, be degraded further. The ecological significance of these results is discussed, particularly with regard to the insecticidal activity of the photoproducts.     

Enantioselective degradation of fipronil in Chinese cabbage (Brassica pekinensis)

Chiral pesticide enantiomers often show different bioactivity and residual toxicity, but this property is usually ignored when evaluating the environmental risk and public safety. In this study, a convenient and precise chiral method was developed and validated for measuring fipronil enantiomers in Chinese cabbage (Brassica pekinensis) based on a high-performance liquid chromatography (HPLC) using (R,R) Whelk-O 1 column. Then the proposed method was successfully applied to the study of enantioselective degradation of fipronil in Chinese cabbage under field conditions. The results showed that the degradation of the two enantiomers in Chinese cabbage was proved to be enantioselective and followed pseudo first-order kinetics (R² ? 0.98). The (R)-enantiomer degraded faster than the (S)-enantiomer, resulting in the relative enrichment of (S)-enantiomer in residue. The detected metabolites MB46513 (desthio), MB45950 (sulfide) and MB46136 (sulfone) by GC–MS suggested that degradation was mainly contributed by oxidization, reduction and photodegradation. Due to the more insecticide activity and lower mammalian toxicity of S-form, the higher concentration of S-fipronil may result in higher activity in crop protection and lower risk to environment and human beings compared to the recemate. This result should be considered in future environmental risk and food safety evaluation.     

Enantioselective microbial transformation of the phenylpyrazole insecticide fipronil in anoxic sediments

Fipronil, a chiral insecticide, was biotransformed initially to fipronil sulfide in anoxic sediment slurries following a short lag period. Sulfidogenic or methanogenic sediments transformed fipronil with half-lives of approximately 35 and 40 days, respectively. In all microbially active sediment slurries tested, the transformation of fipronil to fipronil sulfide was enantioselective. In the sulfidogenic sediment slurry, the enantiomeric fraction (EF) of fipronil decreased from an initial racemic EF value of 0.46 to a value of 0.22 during the incubation period of active fipronil transformation, indicating preferential transformation of the S-(+)-enantiomer. A previously unidentified product, 5-amino1-[2,6-dichloro-4-(trifluoromethyl)-phenyl]-4-(trifluoromethylthio)-1-H-pyrazole-3-carboxyamide, or fipronil sulfide-amide, was detected in the sulfidogenic slurries and coincided with the loss of fipronil sulfide. Biota from methanogenic freshwater sediment slurries also transformed fipronil enantioselectively but with a preference for the R-(-)-enantiomer. In all microbially inhibited (autoclaved) sediment slurries tested, no changes in the enantiomeric fractions of fipronil were observed and only low levels (< 5% of the added fipronil) of the fipronil sulfide metabolite were detected. In defined (model) chemical experiments, solutions of pyrite (FeS2) and iron sulfide (FeS) non-enantioselectively transformed fipronil primarily to either 2,6-dichloro-4-(trifluoromethyl)-aniline or to fipronil sulfide and fipronil amide, respectively. This report provides the first experimental evidence of enantioselective microbial transformation of fipronil in a natural environment (soil, water, and sediment) as well as identification of a novel fipronil biotransformation product.     

Entomotoxic efficacy of aluminium oxide,titanium dioxide and zinc oxide nanoparticles against Sitophilus oryzae (L.): A comparative analysis

The development of resistance in both stored grain and field insect pests to conventional insecticides, coupled with increased consumer awareness of the consequences of their residual toxicity in food crops and environmental contamination have led agro-chemical researchers to reappraise the use of inert dusts as alternative insecticide. Diatomaceous Earth or DE became popular as an alternative insecticide in last two decades for its low mammalian toxicity and physical mode of action. But due to several limitations of DE many researchers are trying to explore the possibility of using nanoparticles as potential insecticide. In this study, a comparison on entomotoxic efficacy of different oxide nanoparticles like aluminium oxide, titanium dioxide and zinc oxide was evaluated on Sitophilus oryzae. Though more than 90% S. oryzae died after 4 days of nano aluminium oxide treatment at 1 g kg⁻¹ dosage, nano zinc oxide and titanium dioxide treatment could attain this efficacy at 2 g kg⁻¹ after 14 days. Even then use of nano zinc oxide and titanium dioxide in agriculture sector is preferred to nano aluminium oxide as the latter nanoparticle has adverse effects on plant growth. Moreover due to the antimicrobial property of nano zinc oxide and titanium dioxide have antimicrobial property, they will not only protect the agricultural produce from insect pests, but also from microbial infection.     

Crops that feed the world 9. Oats- a cereal crop for human and livestock feed with industrial applications

Oats are a low input cereal widely grown across the world as both a grain and forage crop. Significant areas of production are in Northern Europe and North America and also in China and Australia. Although a traditional crop in many countries, in the last 50 years there has been a significant shift in oat production as a consequence of changing agricultural production and competition from other cereal crops. Oats are of significant economic importance for human consumption, for livestock feed and increasingly as a source of high value compounds with industrial applications as a consequence of the many unique properties of the oat grain. Traditional use in human diets in many countries has been boosted by the recent recognition of oats as a health food. This is attributed to the presence of β-glucan, the major endospermic cell wall polysaccharide. As a result, there has been an increase in the use of oats and a broadening of oat based products. Increasing knowledge of the composition of the oat grain and its value for the various end-users is leading to new opportunities for the crop. While the value of oats as a break crop in cereal based rotations is widely recognised, maintaining the profitability of the crop whilst meeting the needs of end users is essential for future production. Opportunities exist for plant breeders and agronomists to introduce new oat varieties with tailored agronomic approaches to address this challenge and to ensure the sustainability of oats for the future.     

食品接触材料中双酚A暴露风险及风险管理

双酚A被广泛应用于食品接触材料中,人体暴露于双酚A可能会带来健康问题.目前中国是世界上最大的双酚A生产国,在全国范围内尚未对双酚A的暴露量进行系统性评估,缺乏相应的食品接触材料数据库.因此,了解食品接触材料迁移的双酚A暴露风险及国内外主要的风险管理措施,对于中国食品安全风险管理策略的制定及消费者食品选择指导具有重要的意...