Emerging frontier technologies for food safety analysis and risk assessment

Access to security and safe food is a basic human necessity and essential for a sustainable world. To perform hi-end rood safety analysis and risk assessment with state of the art technologies is of utmost importance thereof. With applications as exemplified by microfiuidic immunoassay, aptasensor, direct analysis in real time, high resolution mass spectrometry, benchmark dose and chemical specific adjustment factor, this review presents frontier food safety analysis and risk assessment technologies, from which both food quality and public health will benefit undoubtedly in a foreseeable future.

New Strategy for Further Improving the Detection Sensitivity of Direct Analysis in Real Time-Mass Spectrometry

Ambient mass spectrometry facilitates surface detection under ambient conditions and has quickly found its applications in various areas.However,the sensitivity of AMS methods is usually not as good as that of encapsulated ion sources due to less efficient ion transmission.In this work,a briefly machined external ion funnel(threepole electrostatic lens)was adopted and installed between direct analysis in real time and the mass spectrometer inlet to increase detection sensitivity.Software investigation with SIMION version 8.0 was employed to calculate electric fields and to simulate the trajectories of charged particles in the electric field.Both the geometrical parameters of the ion funnel and the electric parameters were studied to obtain the optimal ion focusing results,which demonstrated the ion funnel equipment would greatly improve the ion transmission efficiency.The equipment showed good prospect in direct analysis in real time-mass spectrometry analysis in the future.

用实时直接分析质谱法(DART-MS)快速测定桑叶中的γ-氨基丁酸含量

γ-氨基丁酸（γ-aminobutyric acid,GABA）是桑叶中具有多种药理作用的重要组分之一。为了快速、准确测定桑叶中的GABA含量,建立了基于实时直接分析电离源-串联三重四极杆质谱（DART-MS）的桑叶GABA定性和定量分析方法。在DART离子源和质量分析器同为正离子的模式下,采用选择反应监测模式（SRM）并选取m/z 104→87为定量离子对,以其峰面积（y）进行定量分析,所得线性回归方程为y=4 552 210.19x-11 927 811.70,线性系数R-2=0.998,且在GABA溶液质量浓度（x）为2.50-40.00μg/m L范围内的线性关系良好。对3种质量浓度（7.82、4.14、2.78μg/m L）桑叶样品提取液进行测定的相对标准偏差（RSD）分别为3.98%、5.60%、2.28%,表明该方法的精密度良好;加标回收率在85.60%-97.47%之间。应用DART-MS法对来源于江、浙、皖蚕区的6个桑品种的桑叶样品进行检测,桑叶提取液样品中的GABA质量浓度从高到低的桑品种依次为湖桑32号（7.82μg/m L±0.31μg/m L,江苏海安）、强桑2号（7.44μg/m L±0.21μg/m L,浙江杭州）、强桑1号（7.14μg/m L±0.50μg/m L,杭州）、农桑14号（5.88μg/m L±0.30μg/m L,杭州）、育711号（5.81μg/m L±0.18μg/m L,安徽合肥）、农桑14号（4.25μg/m L±0.29μg/m L,浙江海宁）。建立的DART-MS法用于测定桑叶中的GABA含量,具有简单、快速且灵敏度高等特点。

DART-MS/MS快速检测食品中非法添加的N-苄基他达拉非等7种新型PDE-5型抑制剂

目的将实时直接分析离子源(direct analysis in real time,DART)与三重四极杆质谱联用,建立食品中非法添加PDE-5型抑制剂的快速筛查方法。方法3种不同基质样品加入乙腈振摇10 s后,设进样速率0.2 mm/s,进样体积4μl,选择DART离子源,离子化温度450℃,在正离子、多反应监测(MRM)下进行检测。结果该方法7种物质的检出限为0.025~12.5μg/g,检出阳性样品4种,分别非法添加羟基卡巴地那非、环己基去甲他达拉非、N-苄基他达拉非和N-苯基丙氧苯基卡巴地那非。结论该方法样品前处理简单,分析速度快,定性准确,环境污染小,能满足食品中非法添加PDE-5型抑制剂的快速筛查要求。

In Situ Analysis for Herbal Pieces of Aconitum Plants by Using Direct Analysis in Real Time Mass Spectrometry

In this study,an extend application was developed to in situ analyze the herbal pieces of Aconitum plants by Direct Analysis in Real Time Mass Spectrometry(DART-MS).Nearly all aconitine-type alkaloids can be desorbed and ionized in this method,including diester diterpenoid aconitines(DDAs),monoester diterpenoid aconitines(MDAs)and some other diterpenoid aconitines.The spectra of in situ analysis for the herbal pieces of aconitum plants are similar with that of their extracts.Radix Aconiti and Radix Aconiti Kusnezoffii can be distinguished from each other by the intensity differences of character fragment ions from MDAs,such as m/z 586,572,and 556.The qualified and unqualified herbal pieces can be also identified by the relative abundances of DDAs.The RSD of the relative abundances of some character ions at m/z 556,586,and 590 were 13.53%,4.03%,and 12.03%,respectively.So this in situ analytical method can identify both the types of Aconitum preparata and their quality.It provides the following advantages in the analysis of Chinese herbs:fast detection without much pretreatment,high-throughput analysis,and reduction of pollution without any organic solvent.

Combination of Solid-Phase Micro-Extraction and Direct Analysis in Real Time-Fourier Transform Ion Cyclotron Resonance Mass Spectrometry for Sensitive and Rapid Analysis of 15 Phthalate Plasticizers in Beverages

A method for rapid identification and quantification of phthalate plasticizers in beverages was developed.A number of 15 phthalate plasticizers which covered all the phthalates concerned in the US Consumer Product Safety Improvement Act(CPSIA),European Union legislations and Chinese national standards(GB)were analyzed.By a combined solid-phase micro-extraction(SPME)and direct analysis in real time mass spectrometry(DART-MS)approach,phthalates at sub-ng•mL^(−1)levels can be qualitatively and quantitatively analyzed in a short time.The use of ultrahigh-resolving power and the accurate mass measurement capacity naturally provided by Fourier transform ion cyclotron resonance mass spectrometry(FT-ICR-MS)minimizes the matrix interferences and thus enables the evaluation of phthalates in a complex matrix without extensive sample handlings or preparations.The limits of quantification(LOQs)were estimated to be at 0.3-5.0 ng•mL^(−1),lower than the Maximum Residue Limit(MRL)regulated by the European Union legislations(2007/19/EC)in foods,beverages,food packaging and toys(0.3-30 ng•mL^(−1)).This rapid and easy-to-use SPME-DART-FT-ICR-MS method provided a relatively high-throughput and powerful analytical approach for quick testing and screening phthalates in beverages and water samples to ensure food safety.

Rapid Screening of Nine Illicit Drugs in Human Blood and Urine by Direct Analysis in Real‑Time Mass Spectrometry

We aimed to establish for the rapid detection of morphine,O6‑monoacetylmorphine,heroin,codeine,cocaine,methamphetamine,ketamine,methadone,and dolantin in human blood and urine by direct analysis in real‑time coupled with tandem mass spectrometry(DART‑MS/MS).These samples were extracted by acetonitrile‑methanol(V/V=4:1),using DART 12 Dip‑it automatic sampling system.They were injected at 400℃,and analyzed by positive ion and multiple reaction monitoring mode.The detection limits of morphine,O6‑Monoacetylmorphine,heroin,codeine,cocaine,methamphetamine,ketamine,methadone,and dolantin were 100,50,50,100,20,20,10,1,and 0.01 ng/mL,respectively.The practical cases contained methamphetamine,codeine,cocaine,and O6‑monoacetylmorphine were detected accurately and rapidly.The method has the advantages of high sensitivity and good accuracy.The sample processing is simple and can be analyzed in a short time.This method is suitable for the analysis of morphine,O6‑monoacetylmorphine,heroin,codeine,cocaine,methamphetamine,ketamine,methadone,and dolantin in some practical cases.

DART-MS:A New Research Tool for Herbal Medicine Analysis

Direct analysis in real time(DART) possesses the merits of analyzing sample in its native status with minimal or even no sample pretreatment.In this review, we summarized the recent applications of DART in the field of herbal medicine analysis such as compound detection, species identification, metabolites profiling and initial quantification. DART with the characters of hyper-rapid, easy-hyphenated offers a new research tool for herbal medicines to complete the experimental process in a very simple but still reliable way. It is anticipated that more wide and deep applications of DART in herbal medicine analysis, as rapid quantification, high-throughput active compounds screening, rapid species identification, and fast illegal additives screening will be promising and foreseeable in the near future.

超声萃取雾化碳纤维离子化质谱快速区分当归和欧当归

由于当归与欧当归外形相似,常被不法商贩混淆使用。本研究采用超声萃取雾化碳纤维离子化质谱(UENRT/CFI-MS)法研究当归和欧当归的成分差异,以快速区分二者。以甲醇作为提取溶剂,将药材切片样品置于超声雾化片上,利用超声雾化片的高频振荡实现对样品的在线萃取、过滤和雾化。雾化后的中药样品小液滴在施加高压的碳纤维附近被电离,随后对2种药材的质谱图进行比较分析,寻找差异成分。结果表明,在欧当归的质谱图中识别到m/z 496特征峰,而在当归中未检测到该峰,这一结果为区分2种药材提供了依据。该方法无需繁琐复杂的样品前处理过程,具有分析速度快、操作简单、绿色环保、灵敏度高等优点,能够有效快速区分当归及其伪品欧当归。

采用实时直接分析质谱法原位快速鉴别茶叶

采用近年来发展迅速的常温常压离子化技术——实时直接分析质谱法,建立了对茶叶中主要成分如茶氨酸、咖啡碱等的快速测定方法,通过特征的质谱信号离子,实现了对不同茶叶的快速鉴别。实时直接分析质谱法在大气压下进行,无需对茶叶进行任何的样品处理,大大缩短了分析时间,实现了原位、快速、准确且高通量的检测。

实时直接分析-串联质谱法(DART-MS/MS)快速检测吐根中生物碱

目的:在未经前处理和色谱分离的情况下应用实时直接分析-串联质谱法检测吐根生物碱。方法:在优化的条件下全扫描采集药材,茎及叶的DART-MS(direct analysis in real time,DART)特征图谱,并对生物碱进行二级质谱确证,采用多反应监测模式通过测定样品表面待测物的质谱峰强度来计算其在样品中的平均含量。结果:药材和茎的图谱中均有明显的吐根碱和吐根酚碱的质子化离子峰m/z 481,467,叶中m/z 479,465为其他生物碱的质子化离子峰,定量方法的重复性和线性良好。结论:该模式或在药材、饮片的快速鉴别及实时对中间体或成品的快速定量分析中发挥作用。

DART-Orbitrap质谱法对黄芩药材的快速分析

将实时直接分析（DART）离子源与高分辨率质谱Orbitrap联用,建立了一种对黄芩药材进行快速定性定量分析的方法。定性分析时,对其中的化学成分进行标准品比对和二级质谱确证,同时参考相应文献进行确认。定量分析时,采用Full MS-SIM及Targeted-MS2扫描方式采集信号,Targeted-MS2扫描方式下分别对黄芩素和汉黄芩素的母离子和子离子的提取离子流图积分,通过峰面积计算含量。在黄芩药材中检出黄芩素、汉黄芩素、韧黄芩素Ⅱ、二羟基-二甲氧基黄酮、5,7,2＇,5＇-四羟基-8,6＇-二甲氧基黄酮和SkullcapflavonⅡ的[M＋H]＋峰。定量分析结果显示,黄芩素（m/z 271.06→123.01）的线性范围为49.7～447.3 ng,相关系数（r2）为0.995,平均加标回收率为87.0%;汉黄芩素（m/z 285.07→270.05）的线性范围为50.0～350ng,r2为0.995,平均加标回收率为66.0%。该方法可用于黄芩药材的快速定性检测和定量分析。

DART-Orbitrap质谱法快速定性定量分析延胡索

目的建立一种对延胡索进行快速简便的定性鉴别和定量检测方法。方法采用DART-Orbitrap质谱法进行检测,对延胡索中的化学成分进行对照品比对和二级质谱确证,采用Full MS-SIM/Targeted-MS2扫描方式采集信号,并对延胡索乙素母离子和子离子的提取离子流图积分。结果在延胡索中检测出延胡索甲素和乙素的质子化离子峰,m/z分别为356.18和370.20,定量方法具有良好精密度和稳定性,延胡索乙素的线性范围为0.106~0.848μg/m L,r=0.997 0,平均加样回收率114.1%。结论该方法定量分析时快速精确,并且定性鉴别时无需对样品进行前处理。

实时直接分析-串联质谱法测定葡萄酒中赭曲霉毒素A

建立了葡萄酒中赭曲霉毒素A的实时直接分析-串联质谱(DART-MS/MS)方法。前处理采用乙酸乙酯提取,二甲基十八碳硅烷粉(ODS)粉分散固相萃取净化,采用DART-MS/MS检测,同位素稀释内标法定量。结果表明:在1.0、2.0、10μg/kg 3个加标水平下,回收率为88.7%~105.7%,RSD为8.5%~12.8%,定量限为0.5μg/kg。该方法具有简单、快速、灵敏度高等特点,能满足葡萄酒中赭曲霉毒素A检测的要求。

敞开式离子化质谱新技术及其应用

敞开式离子化质谱(ambient mass spectrometry,AMS)是近年来新兴的一种无需或者只需很少样品前处理步骤,在敞开的大气压环境中可直接对物体表面物质进行离子化的质谱分析技术。本实验室基于敞开式离子源实时直接分析(direct analysis in real time,DART),进行了多方面的研究。主要包括三个方面:第一,应用研究,将简单的样品前处理技术和DART-MS结合,建立了有针对性的快速检测方法;第二,实现正相液相色谱(normal phase liquid chromatography,NPLC)和DART-MS的在线联用,解决了NPLC-MS联用中正相色谱流动相不利于样品离子化的问题,并利用该方法对NPLC分离的手性化合物进行了有效检测;第三,构建了一套新的AMS装置—等离子体辅助多波长激光解吸离子化质谱(plasma assisted multiwavelength laser desorption ioniza-tion mass spectrometry,PAMLDI-MS)。该装置将激光解吸附和等离子体辅助离子化技术相组合,并且将其与简单的TLC快速分离结合,对一些小分子混合物进行了分离检测;实验室还借助简单的铅笔芯中石墨涂覆的滤纸作为PAMLDI-MS的进样基底,发现石墨涂覆的滤纸对于待测样品有很好的基质辅助信号增强作用。

DART-Orbitrap MS快速筛查血液中的130种毒物

血液样品经乙酸乙酯提取、离心、取上清液5μL筛网进样,采用正离子模式扫描进行实时直接分析离子源-静电场轨道阱高分辨质谱（DART-Orbitrap MS）分析,通过比对130种毒物精确分子质量数据库,建立了血液中毒物快速筛查分析方法.结果表明：130种毒物的检出限（以3倍S/N计算）为0.2~50μg/L,质量精确度均在5×10-6μg以内.该方法样品前处理简单、溶剂消耗少,具有分析时间短、灵敏度高的特点,适用于血液中毒物的快速筛查分析.

高分辨质谱技术研究DART离子化条件下的背景离子及潜在应用

运用高分辨质谱技术对实时直接分析(DART)离子化条件下的多种背景离子进行研究和表征,追溯了这些信号可能的来源。研究表明:背景离子主要在阳离子条件下产生,且主要来自实验室环境中微量的增塑剂和聚二甲基硅氧烷,其中聚二甲基硅氧烷可能来自泵油挥发。了解和掌握这些背景离子有助于利用DART技术开展研究和测试方面的工作:(1)这些背景信号较弱,在DART的样品分析时不会产生显著干扰。可在不额外加入内标化合物的情况下,考察高分辨质谱质量轴的稳定性和准确度。(2)了解这些背景离子有助于DART质谱分析复杂体系时避免误判。

实时直接分析质谱法对碧螺春红茶香气物质的快速鉴别

采用实时直接分析质谱法(direct analysis in real time combined with mass spectrometry,DART-MS)快速检测不同产区和不同级别碧螺春红茶的香气物质,结果表明碧螺春红茶的主要特征香气成分主要有酯类、酮类、醛类、酚类等,所体现的花香、果香是碧螺春红茶的香气特征。其中茉莉内酯、百里香酚、柠檬烯、橙花醛、紫罗兰酮等是特征香气成分。东山和西山产区以茉莉内酯、橙花醛、4-乙基愈创木酚、百里香酚、柠檬烯、茶螺烷等为主要的特性香气成分,而无锡和旺山离子种类较少,且离子相对丰度较低;级别较高的碧螺春红茶,离子种类较丰富,离子相对丰度较高,其中烃类物质和酚类物质种类较多,证明级别越高的碧螺春红茶,香气越浓郁。本研究使用一种快速、便捷且不需要样品前处理的方法 DART-MS初步对不同产区和不同级别进行了快速鉴别,为碧螺春红茶品质的提升和指导实际生产提供了参考依据。

实时直接分析-串联质谱法快速筛查火锅底料、牛肉面汤及调味料中罂粟壳生物碱

建立了采用实时直接分析-串联质谱(DART-MS/MS)对火锅底料、牛肉面汤及调味料中5种非法添加的罂粟壳生物碱进行快速筛查的方法。样品经乙腈提取净化后,在离子化温度为300℃、栅极电压为150 V、进样速率为0.8 m m/s的DART离子源正离子模式条件下进样,以电喷雾离子源正离子多反应监测(MRM)模式进行检测,实现了样品经简单预处理后使用DART-MS/MS进行检测的新方法。该方法简便、快速,能满足大批量非法添加样品的快速筛查分析要求。