气球中N-亚硝胺及其前体物迁移量的测定与NDMA的儿童致癌暴露风险分析

用Sep-Pak AC2串联Dry cartridges固相萃取小柱对气球中的7种挥发性N-亚硝胺进行分离净化,并用气相色谱-串联质谱法对其进行定性与定量分析。方法对气球中N-亚硝胺及其前体物的检出限分别为1.25μg/kg和5.00μg/kg。对空白样品进行添加量为2.5μg/kg的加标回收实验,回收率为85%～103%,RSDs(n=3)≤4.6%。分析的气球样品中,N-亚硝基二甲胺(NDMA)及其前体物的检出频率最高;其次是N-亚硝基二乙胺(NDEA)及其前体物;N-亚硝基吗啉(NMOR)、N-亚硝基二丙胺(NDPA)和N-亚硝基哌啶(NPIP)及其前体物均未检出;7种N-亚硝胺及其前体物的总迁移量分别为0.036～0.964 mg/kg和0.259～8.436 mg/kg。6个月～4岁儿童通过口直接接触单个气球样品造成的NDMA的暴露量集中在0.010～0.030mg/kg体重,具有潜在的致癌暴露风险。     

欧盟EN12868方法与固相微萃取-气质联用法检测乳胶气球中亚硝胺模拟迁移量

利用欧盟EN12868方法对市售乳胶气球中的8种挥发性亚硝胺及其前体物的模拟迁移量进行了检测,包括N-亚硝基二甲胺(NDMA),N-亚硝基二乙胺(NDEA),N-亚硝基二丙胺(NDPA),N-亚硝基异丙胺(NDiPA),N-亚硝基二丁胺(NDBA),N-亚硝基哌啶(NPIP),N-亚硝基吡咯烷(NPYR),N-亚硝基吗啉(NMOR)。其中NDMA,NDEA和NDBA 3种亚硝胺及其前体物被检出,且均超标。建立了顶空-固相微萃取-气相色谱-质谱法(HS-SPMEGC-MS)快速测定乳胶气球中亚硝胺模拟迁移量的分析方法。样品置于人工唾液40℃浸提1h来模拟气球的使用情况,考察了不同的萃取条件对分离检测的影响,综合评价了4种检测系统的性能。8种亚硝胺的方法检出限为0.26~5.38μg/kg。利用所建方法检测9种市售乳胶气球中亚硝胺的模拟迁移总量为31.37~337.72μg/kg。     

固相萃取-气相色谱-串联质谱法测定乳胶儿童用品中15种N-亚硝胺及其前体物的迁移量

建立了同时测定乳胶儿童用品中15种N-亚硝胺及其前体物迁移量的固相萃取-气相色谱-串联质谱(SPEGC-MS/MS)分析方法。以人工唾液作为迁移模拟物,以Chromabond Easy固相萃取柱(填料的主要成分是极性修饰的聚乙烯-二乙烯基苯共聚物)对迁移液中的N-亚硝胺分析物进行净化,采用HP-5 MS UI色谱柱分离,MS/MS在多反应监测模式下进行定性及定量分析。15种N-亚硝胺在5~2 000μg/L范围内呈良好的线性关系,相关系数均大于0.998;方法定量限(S/N=10)为0.625~12.50μg/kg,低于欧盟2 009/48/EC指令的限量要求。在低、中、高3个添加水平的回收率为53.8%~116.2%、52.7%~105.1%和49.5%~102.9%;日内精密度分别为1.3%~14.0%(n=6),日间精密度为1.6%~7.6%(n=4)。采用本方法对婴儿奶嘴样品和气球样品进行了测定,其中4件奶嘴和7件气球样品中检出亚硝胺及其前体物,奶嘴和气球中N-亚硝胺的总检出含量分别为0.049 9~0.126mg/kg和0.515~41.2 mg/kg;N-亚硝胺前体物总检出量分别为0.026 4~0.030 0 mg/kg和0.187~12.5mg/kg。     

水蒸气蒸馏-活性炭柱固相萃取/GC-MS/MS法测定火腿中8种N-亚硝胺

建立了水蒸气蒸馏提取,活性炭柱固相萃取,气相色谱-串联质谱(GCM S/M S)检测火腿中8种N-亚硝胺的新方法。样品经水蒸气蒸馏提取,馏出液经Sep-Pak AC-2活性炭柱固相萃取进行净化与富集,二氯甲烷洗脱,以多重反应监测(MRM)方式进行GC-MS/MS检测。在考察的浓度范围内(1~400 ng/m L)方法线性良好,R20.9995,除N-二甲基亚硝胺(NDM A)和N-亚硝基甲乙胺(NMEA)检出限≤0.1 ng/g外,其它分析物的检出限为≤0.04 ng/g;在0.3,3和10μg/kg 3个水平的添加回收率为78.7%~118.2%,除N-亚硝基吗啉(NM OR)回收率略低,为45.2%~58.2%,相对标准偏差为2.5%~21%。应用该方法对市售的4种火腿进行检测,结果表明NDMA和N-亚硝基吡咯烷(NPYR)是主要的挥发性N-亚硝胺,含量分别为0.30 ng/g和0.56~0.99 ng/g,N-二乙基亚硝胺(NDEA)、NMOR和N-二丁基亚硝胺(NDBA)均有检出,但含量低于定量限,NM EA、N-二丙基亚硝胺(NDPA)和N-亚硝基哌啶(NPIP)未检出。     

固相萃取-气相色谱-串联质谱法测定牛奶中9种N-亚硝胺的含量

建立固相萃取-气相色谱-串联质谱法同时测定牛奶中9种N-亚硝胺的分析方法.在10.0 g牛奶样品中加入10 mL乙腈提取9种N-亚硝胺,Captiva EMR-Lipid固相萃取小柱净化提取液,低温微流氮吹浓缩净化液,气相色谱-串联质谱仪采用多反应监测(MRM)模式测定,内标法进行定量.9种N-亚硝胺的线性范围均为0....     

顶空-固相微萃取-气相色谱-质谱法测定乳胶避孕套中亚硝胺的模拟迁移量

采用顶空固相微萃取-气相色谱-质谱法测定了乳胶避孕套中8种亚硝胺的模拟迁移量。参照人工汗液配制方法,配制了酸度为pH 4.5的模拟阴道分泌液。称取避孕套碎片2g于顶空瓶中,加入上述分泌液10mL,在(40±2)℃下磁力搅拌(10±0.5)min。选用CAR/PDMS纤维头在45℃下固相萃取60min,随即将萃取头移至进样口解吸并进行气相色谱-质谱分析。8种亚硝胺的检出限(3S/N)在0.03~0.70μg·kg-1之间。应用此方法分析了8件样品,均检出N-亚硝基二甲胺、N-亚硝基二乙胺及N-亚硝基二丁胺,总亚硝胺的迁移量为9.89~823.41μg·kg-1。     

气相色谱-正化学源质谱法测定家用橡胶手套中7种N-亚硝胺及其前体物的迁移量

该文用Sep-Pak AC2串联Sep-Pak Dry cartridges固相萃取小柱对家用橡胶手套迁移提取液中的N-亚硝基二甲胺(NDMA)、N-亚硝基二乙胺(NDEA)、N-亚硝基二丙胺(NDPA)、N-亚硝基二丁胺(NDBA)、N-亚硝吗啉(NMOR)、N-亚硝基吡咯烷(NPYR)和N-亚硝基哌啶(NPIP)7...     

气相色谱-质谱联用法测定腌制水产品中的挥发性N-亚硝胺类化合物

建立了气相色谱-质谱(GC-MS)快速测定腌制水产品中挥发性N-亚硝胺含量的分析方法。采用GC-MS测定了N-二甲基亚硝胺(NDMA)、N-二乙基亚硝胺(NDEA)、N-二丙基亚硝胺(NDPA)、N-亚硝基吡咯烷(NPYR)、N-亚硝基哌啶(NPIP)、N-二丁基亚硝胺(NDBA)6种化合物,考察了样品不同提取方法、不同固相萃取小柱、不同色谱柱对分离检测的影响。结果显示: 在10～1000 μg/L范围内,线性相关系数可达0.9998以上;重现性良好,相对标准偏差小于8%;回收率可达79%～105%;灵敏度高,检出限低,除NDPA为0.03 μg/kg外,其他5种N-亚硝胺为0.05 μg/kg。该方法前处理快速简捷,易于操作,适用于腌制水产品中N-亚硝胺残留量的检测工作。     

固相微萃取-气相色谱-质谱法测定橡胶密封圈中8种N-亚硝胺含量

采用固相微萃取-气相色谱-质谱法测定橡胶密封圈中8种N-亚硝胺的含量。按国家标准GB/T 24153-2009进行样品的预处理,然后用二乙烯基苯/聚二甲基硅氧烷萃取头,在30℃和800r·min~(-1)转速的条件下萃取45min。在气相色谱分离中用Agilent 1701色谱柱为固定相;在质谱测定中采用选择离子监测模式。8种N-亚硝胺的线性范围均为0.10~2.0mg·L~(-1),方法的检出限(3S/N)均为0.03mg·kg~(-1)。以空白样品为基体进行加标回收试验,回收率在73.0%~96.1%之间,测定值的相对标准偏差(n=6)在1.3%~9.7%之间。     

乳胶制品中N-亚硝胺析出物的GC-MS/SIM检测

使用气相色谱-质谱(GC-MS/SIM)检测了乳胶制品中5种N-亚硝胺析出物,样品经过二氯甲烷萃取,用Rtx-5MS石英毛细管柱分离,采用内标法进行检测计算.实验得出5种N-亚硝基化合物的内标标准曲线日内RSD(小于5%),日间RSD(小于14%).N-亚硝基二乙胺(NDEA)、N-亚硝基二丙胺(NDPA)、N-亚硝基哌啶(NPIP)、N-亚硝基二丁胺(NDBA)、N-亚硝基二苯胺(NDPhA)的方法的检出限分别为2.0,5.0,10.0,1.0,112.0μg/L.运用该法对北京市场的乳胶制品进行了检测.     

GC determination of N-nitrosamines by supersonic molecular beam MS equipped with triple quadrupole analyzer, GC/SMB/QQQ/MS

The determination of 14 N-nitrosamines by a supersonic molecular beam electron ionization mass spectrometer equipped with triple quadruple analyzer, GC/SMB/EI/QQQ/MS is presented. The supersonic molecular beam electron ionization ion source allows the elucidation of the molecular ion of 13 out of the 14 examined nitrosamines (except for diphenylnitrosamine which was degraded before the analysis). It was possible to use the molecular ions of all the nitrosamines as the parent ions for multiple reactions monitoring mode, which in turn allows significant increase of specificity and lowering of the method limit of detection of the higher molecular weight nitrosamines. The instrumental LOD for different N-nitrosamines was 1–5 pg injection⁻¹. The proposed method was exemplified by analysis of N-nitrosamines and N-nitrosatables in rubber teats according to the British Standard BS EN 12868:1999.     

Extraction,confirmation, and screening of non-target compounds in silicone rubber teats by purge-and-trap and SPME combined with GC-MS

As a food contact material, the safety of silicone rubber teats for infants is very important. This analysis of non-target compounds in silicone rubber teats is a prospective work on the safety evaluation and early warning mechanism for similar polymer materials. In this study, two “green” analytical approaches were applied to extract non-target compounds in 30 silicone rubber teats based on the purge-and-trap method and solid phase microextraction. A total of 140 extracted compounds were separated and identified by gas chromatography-mass spectrometry, coupled with three qualitative methods, namely, matching with the mass spectra library, retention index (RI) and standard confirmation. Chromatographic peak area normalization was used to approximate the relative content of each component. A database containing 140 compounds in 12 categories was established. To identify the noteworthy compounds that could migrate and endanger infant health, all compounds were filtered by a three-step screening process based on the detection rate, RI and relative content. Finally, the 53 selected compounds included alkanes, siloxanes, aromatics, aldehydes, trimethylsilanol, butylated hydroxytoluene, N,N-dibutylformamide and benzothiazole. Given their higher detection rate, higher relative content or potential toxicity, these compounds should be further investigated for safety evaluation.     

固相萃取净化及超高效液相色谱-串联质谱法测定橡胶制品中的13种N-亚硝胺

建立了固相萃取(SPE)净化、超高效液相色谱-串联质谱(UHPLC-MS/MS)测定橡胶制品中13种N-亚硝胺的方法。样品于密闭萃取瓶中于60 ℃下用甲醇超声萃取30 min,C₁₈固相萃取小柱对萃取液进行净化,经C₁₈色谱柱分离,最后用电喷雾正离子(ESI⁺)和多重反应监测模式(MRM)对13种N-亚硝胺进行定性、定量测定。实验中对样品前处理、色谱分离条件和质谱检测条件进行了优化。在优化的实验条件下,橡胶样品中添加N-亚硝基二甲胺(NDMA)与N-亚硝基-二乙基胺(NDEA)为500 μg/kg、其他组分均为50 μg/kg时,各组分的相对标准偏差(RSD,n=7)小于10%;在实际样品中的加标回收率为70.7%~117.0%;方法的检出限(LOD,以10倍标准偏差计)为0.5~500 μg/kg。方法可应用于橡胶制品中13种N-亚硝胺的测定。     

Determination of non-volatile N-nitrosamines in baby bottle rubber nipples and pacifiers by high-performance liquid chromatography-thermal energy analysis

A method is described for the determination of non-volatile N-nitrosamines in baby bottle rubber nipples and pacifiers. It consists of extraction of the sample with dichloromethane in the presence of ascorbyl palmitate (an inhibitor of artifactual formation of nitrosamines), clean-up on silica or basic alumina, and final analysis by high-performance liquid chromatography-thermal energy analysis, a technique which is highly specific for N-nitroso compounds. The method worked well for the determination of four rubber-related non-volatile nitrosamines, namely, N-nitrosomethylphenylamine, N-nitrosoethylphenylamine, N-nitrosodicyclohexylamine, and N-nitrosodibenzylamine (recoveries from spiked samples greater than 80%; detection limit, ca. 5 micrograms/kg for each). Eighteen out of twenty four samples analyzed were found to contain varying levels (mean, 41 micrograms/kg; range, 8-146 micrograms/kg) of N-nitrosodibenzylamine. The identity of the compound was confirmed by gas chromatography-thermal energy analysis as well as by gas chromatography-mass spectrometry analyses.     

Optimization of parameters for the supercritical fluid extraction in the determination of N-nitrosamines in rubbers

The study of the possibilities of supercritical fluid extraction (SFE) with N-nitrosamines in rubbers has been carried out. Home-made materials fortified with several N-nitrosamines were prepared in order to optimize the SFE parameters. A Plackett-Burman design was employed to evaluate the influence of those parameters to be controlled in SFE, such as pressure, temperature, static and dynamic time, restrictor temperature and volume of modifier while CO2 was used as the extraction fluid. An extra central composite design for the main factors (according to the previously obtained results) was also developed in order to refine the best supercritical conditions for the extraction of N-nitrosamines from rubbers. Gas chromatography with a nitrogen and phosphorus sensitive detector was used to achieve sensitivity and limits of detection for the concentrations expected in plastic materials. The proposed analytical method has shown to be useful in the determination of N-nitrosamines even for complex matrices.     

Structural features of aliphatic N-nitrosamines of 7-azabicyclo[2.2.1]heptanes that facilitate N-NO bond cleavage

N-Nitrosamines can be considered as potential nitric oxide (NO)/nitrosonium ion (NO(+)) donors. However, the relation of the structures of N-nitrosamines, in particular of aliphatic N-nitrosamines, to the characteristics of release of NO or NO(+) remains unclear. Here we show that aliphatic N-nitrosoamines of 7-azabicyclo[2.2.1]heptanes can undergo heterolytic N-NO bond cleavage. On the basis of the observation of reduced rotational barriers of the N-NO bonds in solution and nitrogen-pyramidal structures of the N-nitroso group in the solid state, we postulate that N-NO bond cleavage of N-nitrosamines is enhanced by a reduction of the resonance in the N-NO group. Computational studies suggest that these structural features of the N-nitrosamines of 7-azabicyclo[2.2.1]heptane are derived from angle strain imposed on the CNC angles.     

分散固相萃取-气相色谱-串联质谱法测定动物源性食品中9种N-亚硝胺类化合物

建立了分散固相萃取-同位素稀释-气相色谱-串联质谱同时测定动物源性食品中9种N-亚硝胺的方法。样品用乙腈提取,上清液经分散固相萃取（dSPE）净化后浓缩。选用DB-WAX极性毛细管色谱柱对待测物进行分离,经EI源电离后以多反应监测（MRM）模式采集数据并做定性筛查和定量分析。9种N-亚硝胺在相应的浓度范围内线性关系良好,相关系数均大于0.99,对4类典型的动物源性食品进行3个不同浓度的加标试验,平均回收率为62.5%~118%,RSD为2.11%~25.6%,检出限（LOD,S/N=3）为0.02~0.31 μg/kg。该方法成本低廉、灵敏可靠,适用于同时对动物源性食品中9种N-亚硝胺进行定性和定量测定。     

微波辐射辅助快速检测微量亚硝胺的研究

分析了分光光度法对于溶液中亚硝胺回收率过低的原因,发现去亚硝基化反应 产物NOBr在吹离溶液过程中分解成为光度法无法检测的NO_x（x < 2）鉴于此,在 装置中增加一个CrO_3氧化管,将生成的NO_x（x < 2）转化成可被显色检测的 NO_2,使亚硝胺回收率高于90%,接近公认标准方法－热能分析仪（TEA）法的类似 指标（76% ～ 96%）;而检测限可达2 * 10~(-8) mol/L。发现微波辐射能使亚硝 胺在低于其沸点的温度下挥发和/或分解,并将其用于倩光度法检测,可以在3 min之内将样品中的亚硝胺收集以供测定,形成快速同时检测环境样品（如烟草） 中微量亚硝胺和氮氧化物的新方法。     

Analysis of odorous compounds in water by isolation by closed-loop stripping with a multichannel silicone rubber trap followed by gas chromatography-mass spectrometry.

An alternative technique for the isolation and concentration of odorous compounds found in potable water is described. The method currently employed by water authorities is closed-loop stripping with the collection of these substances on a small activated carbon filter. The compounds of interest are then extracted from the carbon using a suitable solvent. The authors offer a multichannel silicone rubber trap as an alternative to the carbon filter. The absorbed compounds are thermally desorbed from the trap, directly on to the gas chromatographic column for analysis by GC-MS, thereby eliminating the solvent extraction step required by the carbon filter. The multichannel silicone rubber trap, producing equivalent results, offers a number of advantages over the carbon filter.