电感耦合等离子体串联质谱测定水产品中的痕量重金属元素

建立了电感耦合等离子体串联质谱(inductively coupled plasma tandem mass spectrometry,ICP-MS/MS)法准确测定水产品中多种痕量重金属元素的分析方法。针对ICP-MS/MS分析中复杂基质所形成的质谱干扰,在MS/MS模式下,向八极杆碰撞反应池(octopole reaction system, ORS)中通入O_2为反应气,分析离子Cr~+、Ni~+、As~+能与O_2反应分别生成CrO~+、NiO~+、AsO~+,而干扰离子不与O_2反应,利用O_2质量转移法消除了质谱干扰,选择Sc、In、Bi为内标元素校正了基体效应并防止了分析信号的漂移,实现了水产品中痕量重金属元素Cr、Ni、As、Cd、Hg、Pb的无干扰测定。采用扇贝成分分析标准物质(GBW10024)并验证了所建立方法的准确性。分析元素的检出限为0.85～4.28 ng/L,相对标准偏差≤4.65%。ICP-MS/MS的反应模式是克服质谱干扰的有效手段,可以在痕量水平上准确测定水产品中的多种重金属元素。     

食用橄榄油中重金属元素的质谱分析

建立了电感耦合等离子体质谱(ICP-MS)法直接测定橄榄油中Cr、Ni、As、Cd、Hg、Pb等6种重金属元素的分析方法。样品经正丙醇+二甲苯(70:30,V/V)有机溶剂稀释后直接进入ICP-MS进行分析,有机样品可以长时间保持稳定以满足多元素的测定要求,在等离子气中引入少量氧气,以防止样品溶液中的高碳在质谱采样锥锥孔沉积导致分析元素的灵敏度降低。应用碰撞/反应池技术校正了多原子离子对待测元素产生的质谱干扰,采用Rh为内标元素校正了质谱分析中的基体效应。6种重金属元素的检出限在17.58~53.81 ng/L之间,加标回收率在94.00~107.00%之间,相对标准偏差(RSD)为1.33~2.80%。     

ICP-MS法直接测定食用黄油中的重金属元素

建立了电感耦合等离子体质谱(ICP-MS)法直接测定食用黄油中Cr、Co、Ni、As、Cd、Sb、Hg、Pb等8种重金属元素的分析方法。黄油经正丙醇+二甲苯(70:30,V/V)稀释后直接进入ICP-MS进行分析,有机样品可以长时间保持稳定以满足多元素的测定要求,在等离子气中引入少量氧气,以防止样品溶液中的高碳在质谱采样锥锥口沉积导致分析元素的灵敏度降低。应用ORS技术校正了多原子离子对待测元素产生的质谱干扰,采用Rh为内标元素校正了质谱分析中的基体效应。8种重金属元素的检出限在0.6~22.1 ng/L之间,加标回收率在92.6%~106.0%之间,相对标准偏差(RSD)为1.6%~3.4%。     

微波消解-电感耦合等离子体质谱法同时测定蜂胶中的5种重金属元素

目的建立微波消解-电感耦合等离子质谱法(microwave digestion-inductively coupled plasma mass spectrometry,MWD-ICP-MS)同时测定蜂胶中铅(Pb)、砷(As)、汞(Hg)、镉(Cd)、铬(Cr)5种常见重金属元素。方法样品加HNO_3 5.0 m L和H_2O_2 1.0 m L进行微波消解,赶酸温度为110℃;采用ICP-MS法直接测定Pb、As、Hg、Cd、Cr 5种重金属元素的含量。结果 Pb、As、Cd、Cr在1~500μg/L线性范围内,Hg在1~5.0μg/L线性范围内都具有良好的线性关系,相关系数r0.999,检出限为0.012~0.015 mg/kg,加标回收率为95.3%~101.8%。该方法测得蜂胶中的Pb含量为2.16 mg/kg、As含量为0.23 mg/kg、Hg含量为0.03 mg/kg、Cd含量为0.06 mg/kg、Cr含量为1.2 mg/kg。结论该方法具有良好的准确度和精密度,检出限低,适用于蜂胶中常见重金属元素的同时测定。     

ICP-MS法测定食用明胶中重金属元素

利用电感耦合等离子体质谱法(ICP-MS)测定食用明胶中Cr、Mn、Ni、As、Cd、Sb、Hg、Pb等8种重金属元素的分析方法。通过优化仪器的工作参数、选择适宜待测元素的同位素以及选用干扰元素校正方程可以克服质谱干扰,以Sc、Rh、Bi为内标元素,样品的基体效应和仪器漂移得到了很好地校正。结果表明,8种重金属元素的检出限在0.002～0.091μg/L之间,RSD<2.11%,回收率在91.5%～109.0%之间,方法与其他分析对照,结果一致。     

ICP-MS法测定皮革和纺织品中可萃取重金属含量

建立了电感耦合等离子体质谱(ICP-MS)法同时测定皮革和纺织品中10种可萃取重金属元素As、Cd、Cr、Co、Cu、Ni、Sb、Pb、Hg、Zn的含量。各元素的线性相关系数均≥0.999,方法检出限为:0.0015~0.85 mg/kg;同时进行加标回收实验,不同浓度的加标回收率均在88.0%~107%之间。精密度为1.73%~5.27%;可以满足测定的要求。     

基于电感耦合等离子体-串联质谱技术测定猪肉和鸡肉中32 种元素含量

建立电感耦合等离子体-串联质谱（inductively coupled plasma tandem mass spectrometry,ICP-MS/MS）测定猪肉和鸡肉中32 种元素含量的分析方法。样品采用微波消解处理,利用ICP-MS/MS在No gas、He、H2、O2和NH3/He 5 种模式下测定样品中多元素含量,利用目标离子与反应气发生碰撞或反应,用原位质量和质量转移方式消除分析过程中质谱干扰。结果表明：32 种待测元素在0～100 μg/L和0～1 000 μg/L范围内线性关系良好,R2≥0.999 2,检出限为0.000 028～0.130 063 mg/kg,加标回收率为91.6%～109.7%,相对标准偏差≤4.6%;对实际样品进行测定,样品中P、S、K、Na、Ca、Mg等元素含量相对较高,有害元素Cr、As、Cd、Pb的含量符合国家食品安全标准。     

基于ICP-MS/MS技术测定食用植物油中22种微量元素

基于电感耦合等离子体串联质谱（ICP-MS/MS）测定食用植物油中的22种微量元素。食用植物油样品采用煤油稀释后直接进样分析，在MS/MS模式下，分别采用H2、O2、NH3/He为反应气，使干扰物或分析物与反应气发生质量转移反应，利用原位质量法或质量转移法消除质谱干扰。结果：各待测元素线性关系良好，线性相关系数≥0.9996。22种元素的检出限在0.35～307.84 pg/g范围。采用加标回收法验证方法的准确性，加标回收率在96.60%～105.46%之间，相对标准偏差（RSD）≤3.99%。采用所建立的方法分别测定来自国内不同地区的菜籽油、花生油、葵花籽油、玉米油和橄榄油等常用食用植物油，结果显示：5种食用植物油中P、S、K、Na、Ca的含量较高，而重金属元素Cr、As、Cd、Hg、Pb的含量很低。该方法具有样品处理简单、灵敏度高、检出限低的特点，能准确监控食用植物油中的营养性元素和安全性元素。     

ICP-MS法直接测定氢化植物油中的重金属元素

建立了煤油稀释样品,电感耦合等离子体质谱(ICP-MS)法直接测定氢化植物油中Cr、Ni、Cu、As、Cd、Sb、Hg、Pb等8种重金属元素的分析方法。通过向等离子体气中混入20%的氧气以消除有机样品中高碳的影响,详细地研究了在加氧情况下载气流速、等离子体功率和样品提升量对等离子体稳定性的影响,采用碰撞/反应池(CRC)技术校正了多原子离子质谱干扰,选择内标法校正了基体效应。结果表明,8种重金属元素定量标准曲线的线性相关系数不小于0.999 8,检出限在0.13~2.06 ng/g之间,RSD为2.26%~4.81%,加标回收率在91.23%~106.55%之间。方法能满足氢化植物油中重金属元素的分析要求。     

用ICP-MS法测定卷烟烟气中的重金属元素

用电感耦合等离子体质谱 (ICP MS)法定量分析了 4种卷烟烟气中Pb、Cd、Cr、Hg和Ni5种重金属元素的含量 ,其CV值绝大多数小于 5 % ,回收率在 89.3%～ 10 5 .0 %之间。ICP MS方法具有同时分析多种含量在ng/L～mg/L范围内的元素 ,分析速度快 ,样品前处理简单 ,干扰少等优点     

Application of Orbitrap-mass spectrometry to differentiate isomeric sildenafil- and thiosildenafil-like analogues used for the adulteration of dietary supplements

Two groups of isomeric phosphodiestrase-type 5 inhibitors (PDE-5), consisting of four sildenafil- and three thiosildenafil-like analogues, have been successfully differentiated using high-resolution MS/MS. The optimised MS/MS data obtained from each compound were used to build a database with the aid of mass processing software. Isomeric compounds with very close chromatographic separation like dimethylsildenafil and homosildenafil could be distinguished by their unique fingerprint fragment ions in the MS/MS database. All fragment ions were within the mass tolerance of 5 ppm. One case study using an adulterated dietary supplement is included to provide more insights into this application.     

LC/MS/MS法测定白酒中氨基甲酸酯类农残研究

首次建立同时对蒸馏白酒中8种氨基甲酸酯类农药(抗蚜威、恶虫威、克百威、仲丁威、甲萘威、扑灭威、多菌灵、灭多威)残留的液相色谱串联质谱法(liquid chromatography-tandem mass spectrometry, LC/MS/MS)定性鉴别和定量测试方法,此8种农药残留的方法检出限为0.5 μg/kg^10 μg/kg。上述8种农药残留在蒸馏白酒中加标回收率为87.6 %~100.0 %,精密度为0.89 %~5.6 %,均能够满足测试要求。     

Stable isotope dilution analysis of the Fusarium mycotoxins deoxynivalenol and 3-acetyldeoxynivalenol

Trichothecenes are secondary metabolites produced by several fungi of the Fusarium genus during their growth period. They inhibit protein biosynthesis in eukaryotic cells resulting in numerous toxic effects such as diarrhea, vomiting, and gastro-intestinal inflammation. Considering its occurrence in food and feedstuff, deoxynivalenol (DON) is one of the most important trichothecenes. We report the synthesis of stable isotope labeled 15-d(1)-deoxynivalenol (15-d(1)-DON) from its natural precursor 3-acetyldeoxynivalenol (3-AcDON) as starting material. Furthermore, a method for the analysis of DON and 3-AcDON using HPLC-MS/MS with stable isotope labeled 15-d(1)-DON and 3-d(3)-AcDON as internal standards has been developed. In total, 18 cereal product samples were analyzed with contamination levels ranging from 10-301 microg/kg for DON and 5-14 microg/kg for 3-AcDON. This is the first report of an isotope dilution MS method for the analysis of type B-trichothecenes.     

水产品中四环素类药物残留的超高效液相色谱-串联质谱测定

建立同时测定水产品中6 种四环素类药物残留的超高效液相色谱- 串联质谱(UPLC-MS/MS)分析方法。用0.01mol/L Na2EDTA-Mcllvaine 磷酸盐缓冲溶液提取,样液过滤后正己烷除脂,经Oasis HLB 固相萃取柱净化,甲醇洗脱,氮气吹干缓冲液定容后,用反相液相色谱分离,电喷雾正离子模式离子化,用多反应监测模式(MRM)监测,三重四级杆质谱测定,外标法定量。该法对四环素类药物在5.0～50.0μg/kg 范围内呈线性关系,相关系数r 在0.9969～0.9999 之间,在5.0、10.0、25.0、50.0μg/kg 添加水平,回收率为61%～97%,相对标准偏差(RSD)为1.3%～5.7%,其检出限达2.5μg/kg,方法操作简便,稳定性好,选择性好,灵敏度高。     

食物过敏原蛋白的定量检测方法

食物过敏现象的日益严重凸显食物过敏原蛋白定量检测的重要性。目前对食物过敏原蛋白进行定量检测的方法多是基于单个蛋白的间接测定。随着质谱分析方法的进步,定量蛋白质组学技术已开始并将广泛应用于复杂食品混合物中微量过敏原的直接定量检测。本文分别对基于单个蛋白和蛋白质组学的食物过敏原蛋白的定量测定方法进行综述。     

食用植物油中痕量游离棉酚的超高效液相色谱-串联质谱测定

建立了超高效液相色谱-三重四级杆-串联质谱法(UPLC-ESI-MS/MS)测定食用植物油中游离棉酚的含量,以乙醇为提取溶剂提取食用植物油中的游离棉酚,采用Waters AQUITY UPLC BEH C18色谱柱进行分离,以乙腈-0.1%的甲酸水溶液作为流动相,梯度洗脱。在电喷雾离子源(ESI)负离子模式和多反应通道监测(MRM)模式下进行定量分析。结果表明:棉酚的质量浓度在0.005～5.0μg/mL范围内线性关系良好,方法检出限LOD (S/N≥3)为10μg/kg,定量限LOQ (S/N≥10)为50μg/kg。以0.25、2.5、25μg/g 3个不同棉酚浓度进行加标后测得平均加标回收率为80.3%～112.6%,相对标准偏差小于11%,精密度0.42%。该方法灵敏度高,测定结果准确,回收率稳定,适用于确证检测食用植物油中的棉酚残留。     

Pyrrolizidine alkaloids in honey: comparison of analytical methods

Pyrrolizidine alkaloids (PAs) are a structurally diverse group of toxicologically relevant secondary plant metabolites. Currently, two analytical methods are used to determine PA content in honey. To achieve reasonably high sensitivity and selectivity, mass spectrometry detection is demanded. One method is an HPLC-ESI-MS-MS approach, the other a sum parameter method utilising HRGC-EI-MS operated in the selected ion monitoring mode (SIM). To date, no fully validated or standardised method exists to measure the PA content in honey. To establish an LC-MS method, several hundred standard pollen analysis results of raw honey were analysed. Possible PA plants were identified and typical commercially available marker PA-N-oxides (PANOs). Three distinct honey sets were analysed with both methods. Set A consisted of pure Echium honey (61–80% Echium pollen). Echium is an attractive bee plant. It is quite common in all temperate zones worldwide and is one of the major reasons for PA contamination in honey. Although only echimidine/echimidine-N-oxide were available as reference for the LC-MS target approach, the results for both analytical techniques matched very well (n?=?8; PA content ranging from 311 to 520?µg?kg^?1). The second batch (B) consisted of a set of randomly picked raw honeys, mostly originating from Eupatorium spp. (0–15%), another common PA plant, usually characterised by the occurrence of lycopsamine-type PA. Again, the results showed good consistency in terms of PA-positive samples and quantification results (n?=?8; ranging from 0 to 625?µg?kg^?1 retronecine equivalents). The last set (C) was obtained by consciously placing beehives in areas with a high abundance of Jacobaea vulgaris (ragwort) from the Veluwe region (the Netherlands). J. vulgaris increasingly invades countrysides in Central Europe, especially areas with reduced farming or sites with natural restorations. Honey from two seasons (2007 and 2008) was sampled. While only trace amounts of ragwort pollen were detected (0–6.3%), in some cases extremely high PA values were detected (n?=?31; ranging from 0 to 13019?µg?kg^?1, average?=?1261 or 76?µg?kg^?1 for GC-MS and LC-MS, respectively). Here the results showed significantly different quantification results. The GC-MS sum parameter showed in average higher values (on average differing by a factor 17). The main reason for the discrepancy is most likely the incomplete coverage of the J. vulgaris PA pattern. Major J. vulgaris PAs like jacobine-type PAs or erucifoline/acetylerucifoline were not available as reference compounds for the LC-MS target approach. Based on the direct comparison, both methods are considered from various perspectives and the respective individual strengths and weaknesses for each method are presented in detail.     

超高效液相色谱-串联质谱法测定干香菇中的多菌灵和噻菌灵残留量

称取1.0g 干香菇样品,用0.02mol/L 盐酸- 甲醇(80:20,V/V)溶液浸泡提取,调节溶液pH 值至6～8,用二氯甲烷进行提取净化,旋转蒸发器减压蒸干后,用30% 甲醇水溶解,样液用超高效液相色谱分离,电喷雾串联四级杆质谱进行检测,外标法定量。本法研究的多菌灵和噻菌灵的线性范围为1.0～100.0μg/L,线性相关系数R2 ＞ 0.99,在1.0～10.0μg/kg 的3 个添加水平范围内的平均回收率为78%～106%,相对标准偏差为7.9%～9.8%,方法检测限可达1.0μg/kg,在3min 内快速完成分析测试,可应用于大通量的实际样品检测。     

Estimation of selenium intake in Switzerland in relation to selected food groups

The selenium concentration in foods was analysed in order to identify principal sources of this trace element in Switzerland. Selenium intake estimations based on three different approaches were carried out. From the relationship between intake and serum/plasma concentration, the selenium intake was estimated to 66 µg day^?1. The second approach based on measured food groups combined with consumption statistics; and the third approach consisted of duplicate meal samples. With the last two methods, over 75% of the serum/plasma based intake was confirmed. Swiss pasta made of North American durum wheat was the food with the highest contribution to the dietary intake, followed by meat. The strong decrease in imports of selenium-rich North American wheat of the last years was not reflected in the present intake estimations. It appears that this intake loss was compensated by a consumption increase of other foods. Compared with former intake estimations, selenium intake seems to be in Switzerland nearly constant for the last 25 years.     

基于UPLC/Q-TOF MS/MS的花生油成分分析

采用超高效液相色谱-串联四级杆飞行时间质谱(UPLC/Q-TOF MS/MS)联用仪对花生油甲醇提取液分离检测,分析花生油成分,并通过二级质谱图和标准品确定物质。结果表明:正离子模式下检出86种化合物,鉴定30种物质,其中芥酸、棕榈酰胺、硬酯酰胺、油酸酰胺、11Z-二十二碳二烯酸为已知的花生油成分,亚油酰乙醇胺、亚油酰胺、鞘氨醇、N-油酰乙醇胺、十八碳四烯酸、顺-4-癸二酸等26种物质均为首次被检出;在负离子模式下,共检出27种化合物,鉴定15种物质,其中包括花生油中常见的7种脂肪酸,首次检出(Z)-13-氧-9-十八烯酸、蓖麻油酸、烯油酸、13-羟基十八酸和2(R)-羟基海藻酸5种脂肪酸和其他3种物质。