食物污染不是一个新问题。这就是为什么食品生产商小心翼翼地进行风险评估并保持其运营尽可能卫生的原因。但是近年来，新一类污染物的兴起已成为该行业的主要关注点。

These emerging contaminants, also known as contaminants of emerging concern,¹can enter the water supply and food chain through industrial wastewaters²and include the likes of medicines, personal care products, agricultural chemicals and microplastics. These compounds were not designed to be ingested with foods in this way, and as a result, their effects on human and animal health are generally not yet well understood and potentially dangerous.

Given the potential risks presented to consumers, an increasing number of these contaminants are now routinely screened for in the food industry. Today, this is predominantly done with the aid ofmass spectrometry(MS) techniques, such as high-resolution mass spectrometry (HRMS) or tandem mass spectrometry (MS/MS), but scientists are continuously trying to develop new and improved methods to deal with these emerging risks.

Two exciting developments currently being investigated are the application of new MS methods and the development of electrochemical aptamer-based biosensors for the rapid and inexpensive detection of emerging contaminant residues.

Going further with mass spectrometry

MS是一种非常敏感的分析技术，这意味着可以有效地检测到每万亿级的零件的新兴污染物。结果，HRMS和MS/MS方法已被广泛用于新兴污染物筛选。 ³

“For HRMS, one of the key advantages is that a sample can be retroactively analyzed, and so there's no need to have some sense of what the target compounds are ahead of time. So long as the fragments and empirical masses are determined, one can piece together the puzzle of what contaminants are in the material,” said food scientist, author and food industry consultant, Dr. Bryan Le 。

但是，尽管这些方法是有效的，但它们仍然可以进行改进。以前，方法一次倾向于一次只关注一类污染物，因此很难研究多种潜在的风险。鉴于新兴污染物的纯粹化学多样性，实际上需要采用更“通用”的分析方法，该方法可以在一次运行中检测出更广泛的潜在污染物残基的范围。

In 2008, Mol et al. ⁴ 开发了第一种综合方法，该方法能够在一个分析程序中结合对几个物质类别的筛选。多级方法的开发一直在继续，最终在发表论文中Analytical and Bioanalytical Chemistry ⁵ earlier this year that describes a multi-class approach capable of covering over 1000 unique substances in a single analytical run.

使用此方法 液相色谱与串联质谱法 (LC-MS/MS) to study over 1000 compounds in 2 cattle feed matrices and was internally developed and validated by researchers at the 大学of Natural Resources and Life Sciences , and the Austrian Competence Center for Feed and Food Quality, Safety and Innovation 。In the interest of minimizing the workload associated with the method, the researchers chose to use a simple “dilute and shoot” sample preparation method.

“Chemical contaminants are the most suitable for [screening with] this technology, for this MS approach, and there are a lot of potential uses,” said Dr. Angela Anandappa, founding director of the non-profit Alliance for Advanced Sanitation 以及东北大学食品科学和风险评估的讲师。

“I’m hoping we will see lots more reference points for pesticide residues and similar contaminants that can be monitored through this technology. In all these cases, it’s important for us to use the latest tools and reference standards so that new and emerging food safety risks can be better identified and classified before announcements of success can be made.”

Indeed, further development and refinement of such multi-class methods will be needed before this technique is likely to challenge traditional MS/MS and HRMS in the average testing laboratory. For example, the researchers behind the newAnalytical and Bioanalytical Chemistrypaper also report current issues with “overwhelming data management” in some analytical runs. But with further validation, the research group believes that implementing sensible performance guidelines on this issue could open the door to new possibilities for simultaneous contaminant detection.

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用于快速筛选的电化学适中器

Other avenues for innovation in food testing have moved away from the MS approach altogether.

抗菌残留物是与食品行业最相关的新兴污染物类别之一。由于在动物饲养中使用抗菌素，这种污染往往会影响动物来源的食品。这些通常是使用物理化学技术（例如LC-MS/MS）进行筛选的，但也可以使用免疫测试检测（例如，例如， enzyme-linked immunosorbent assay （ELISA））或微生物板测试。

Biosensors have recently emerged as a new avenue for development to overcome some of the limitations of these existing methods. While microbiological techniques are inexpensive, they can lack sensitivity for some types of antimicrobial drugs. Immunological assays are quick and sensitive to a broad range of antimicrobials, but the cost of this testing can grow dramatically as the number of antimicrobial families for which screening is required rises. Techniques such as LC-MS/MS offer the best sensitivity but are extremely costly. Researchers in the field believe that effective biosensors could represent a cheaper, portable testing solution that still retains good sensitivity.

电化学适中器 ⁶ are one of the major technologies being proposed for this purpose. These are a class of biosensor that utilize an aptamer – the name given to a single-stranded DNA or RNA molecule – as the recognition element of the biosensor. This aptamer can easily be modified chemically to ensure a good affinity for the target molecules in question and can be functionalized further with nanomaterials to improve a variety of performance characteristics, including sensitivity and stability.

Le解释说：“基于适体的传感器是最先进的分析技术，对包括重金属离子，毒素，病原体和小分子在内的各种分析物高度敏感。”

“Much of the research has been concentrated towards diagnostic uses in the medical field, and so the technology is not yet in standard practice for food applications and there are no large-scale commercial manufacturers for aptamer-based sensors used to detect food contaminants. However, aptamers are more cost-effective than antibody-based sensors and would be valuable for the on-site detection of contaminants. They are a promising new technology that will drive down the cost of ELISA-like assays that use aptamers在代替of antibodies as the binding platform.”

A recent scientific review ⁷ of electrochemical aptasensors for antimicrobial screening in food products found numerous instances where proof-of-concept devices were able to detect and quantify antimicrobial drugs effectively in a given sample. Detecting the use of widely banned antibiotics (such as chloramphenicol ⁸ ) appears to be an area of particular interest, ⁷ as it is crucial to avoid false positives in these cases. The specificity of the electrochemical aptasensor could be used to great advantage here.

该评论还突出了一些未来改进的领域。最关键的是，这些传感器仍然需要在更真实的样品上进行测试。评论中发现了一些研究，这些研究报告了能够测试牛奶样品的方法学 effectively, ⁹ but the technique still needs to be proven to be useful for testing solid foods. Additional validation assays must be carried out before these electrochemical aptasensors can be considered more than a proof-of-concept. Still, from the existing literature, it is clear that this technique holds a lot of potential promise for the future.

在工业农业中使用农药，在动物饲养中的抗菌素以及个人护理产品和药物的一般使用是现代生活中不可避免的。只要是这种情况，至关重要的是，科学家可以有效地测试这些化合物的痕迹作为污染物。多级MS和廉价但敏感的生物传感器的开发只是科学家目前正在探索的两条途径，以应对新兴污染物所带来的威胁，但是这两种技术都表现出对未来的巨大希望，这极大地鼓舞了人们。

References

1。Emerging Contaminants. U.S. Geological Survey.https://www.usgs.gov/mission-areas/water-resources/science/emerging-contaminants?qt-science_center_objects=0#qt-science_center_objects。Accessed May 21, 2021.

2。Beadle A. Emerging contaminants in water: sources, effects and treatments. Technology Networks.//www.qianliexian123.com/applied-sciences/articles/emerging-contaminants-in-water-sources-effects-and-treatments-296802。Published 2018. Accessed May 21, 2021.

3.FarréM，BarcelóD，BarcelóD。食品中新兴污染物的分析。TrAC Trends Anal Chem。2013; 43：240-253。doi：10.1016/j.trac.2012.12.003

4。Mol HGJ, Plaza-Bolaños P, Zomer P, De Rijk TC, Stolker AAM, Mulder PPJ. Toward a generic extraction method for simultaneous determination of pesticides, mycotoxins, plant toxins, and veterinary drugs in feed and food matrixes.肛门化学。2008; 80（24）：9450-9459。doi：10.1021/ac801557f

5。Steiner D, Malachová A, Sulyok M, Krska R. Challenges and future directions in LC-MS-based multiclass method development for the quantification of food contaminants.Anal Bioanal Chem。2021;413(1):25-34. doi:10.1007/s00216-020-03015-7

6。Di Pietrantonio F, Cannatà D, Benetti M. Chapter 8 - Biosensor technologies based on nanomaterials.Micro and Nano Technologies。Elsevier; 2019:181-242. doi:10.1016/B978-0-12-814401-5.00008-6

7。Gaudin V. Contribution of Nanomaterials to the development of electrochemical aptasensors for the detection of antimicrobial residues in food products.化学素。2021;9(4). doi:10.3390/chemosensors9040069

8。FAO urges countries to discontinue the use of chloramphenicol in animal production. Food and Agriculture Organization of the United Nations.http://www.fao.org/asiapacific/news/detail-events/en/c/47419/。Published January 24, 2002.

9。Mohammad Danesh N, Ramezani M, Sarreshtehdar Emrani A, Abnous K, Taghdisi SM. A novel electrochemical aptasensor based on arch-shape structure of aptamer-complimentary strand conjugate and exonuclease I for sensitive detection of streptomycin.Biosens Bioelectron.2016;75:123-128. doi:10.1016/j.bios.2015.08.017