色谱与色谱/质谱法相结合分析热裂解汽油C9馏分

采用毛细管气相色谱-氢火焰离子化检测器（CGC-FID）和气相色谱-质谱法(GC/MS)分析了热裂解汽油C9 馏分的组成。实验使用PONA毛细管气相色谱柱(100 m×0.25 mm i.d.×0.5 μm),根据烃类化合物在PONA柱上的保留规律,以正构烷烃标样保留值作为碳数分布依据,定量分析了裂解汽油C9 馏分中烃类化合物的碳数分布和单体烃含量;用GC/MS联用技术和CGC保留值定性法相结合对裂解汽油C9 馏分中相对含量大于0.2%的39种化合物进行了定性。     

裂解气相色谱-质谱法分析裂解气压缩机垢样的组成

采用裂解气相色谱-质谱联用技术对大庆石化公司裂解气压缩机EC301不同压缩段的垢样进行分析。实验使用了RJ-1型管炉式裂解器,在500℃下对垢样进行裂解,色谱柱为60 m DB-1型毛细管色谱柱,质谱采用电子轰击电离源,电离能70 eV。研究表明,垢样的形成与环戊二烯密切相关。裂解气相色谱-质谱法可以作为分析该垢样成因的有效手段。     

沙门氏菌全细胞的热裂解气相色谱-质谱分析

本研究探讨了一种新型的快速检测食源性病原菌的方法。该方法应用热裂解气相色谱-质谱技术(pyrolysis-gas chromatography-mass spectrometry,Py-GC-MS)对食源性致病菌沙门氏菌进行了分析。通过对影响总离子流色谱图条件(热裂解条件、色谱条件、质谱条件)的研究,得到了满意的实验结果。结果表明:沙门氏菌全细胞在裂解温度600℃,时间为10s,离子源温度220℃,电离方式为EI,电离能为60eV的条件下可得到清晰的总离子流色谱图,同时对部分裂解产物的结构进行了鉴定。该方法快速、简便,可为研究快速鉴定致病菌提供新的技术手段。     

裂解气相色谱-质谱法鉴别汽车用非金属材料

建立了裂解气相色谱-质谱联用法(PY-GCMS)测试汽车用非金属材料,包括其中主体材料及有机添加剂的定性分析。首先将样品进行逸出气体分析(EGA),然后根据是分析非金属材料中的添加剂还是主体材料来选择合适的裂解温度,进行裂解气相色谱-质谱分析。试验结果表明,不同材料可根据裂解后的特征峰及所使用的添加剂进行鉴别。该方法无需样品前处理,样品用量少,是一种快速鉴别和测定汽车用聚合物材料的有效方法。     

裂解气相色谱-质谱联用法分析聚醚酰亚胺的裂解产物

应用裂解气相色谱及质谱联用法研究了3种聚醚酰亚胺(PEIM′s)的裂解行为,并根据裂解产物的结构及其相对产率推断了裂解的机理。取3种PEIM样品置于石英裂解管中,分别在550℃,650℃,750℃条件下裂解,所得产物用气相色谱-质谱联用法分析。分析中采用DB-5毛细管色谱柱,电子轰击离子源(200℃,70eV)及在m/z 29～500范围内全扫描方式,并用NIST谱库进行检索和用归一化法计算峰面积进行定量。由试验结果可知:选择在750℃进行裂解较好,在此条件下获得主要裂解产物存在的更明显的信息,有利于对产物进行详细分析和鉴定。     

气相色谱-氮化学发光检测法分析催化汽油中含氮化合物类型的分布

建立了催化汽油馏分中各种含氮化合物类型分布的气相色谱-氮化学发光检测分析方法,考察了各种色谱条件对含氮化合物分离的影响。采用化学预处理的方法浓缩了催化汽油中的含氮化合物,并结合气相色谱-质谱检测以及部分含氮化合物标准样品,对某催化汽油中的20多个含氮化合物进行了定性(或归类)。催化汽油中几种主要含氮化合物(苯胺、2-甲基苯胺、二甲基苯胺)含量测定值的相对标准偏差(RSD)均不大于2.5%。当信噪比(S/N)为3时,苯胺氮的检出限为1.0 mg/L。该方法可用于不同来源和不同加工工艺的汽油馏分中各种含氮化合物类型分布的研究。     

果蔬中107种残留农药的气相色谱-质谱检测方法

采用毛细管气相色谱-质谱法对果蔬中107种残留农药检测进行了系统研究,考察了被测组分在不同极性毛细管色谱柱上的保留时间值,对比了不同前处理技术对检测结果的影响,确定了气相色谱-质谱检测农残初筛离子选择原则,规定了气相色谱-质谱确证被捡出农药应符合的条件。     

裂解同时烷基化气相色谱/质谱鉴定醇酸树脂

 用裂解同时烷基化气相色谱-质谱联用技术（SPM-GC-MS）对不同类型的醇酸树脂进行分析研究,将衍生化试剂四甲基氢氧化胺与样品同时裂解,经高效毛细管气相色谱分离,质谱鉴定,可区分醇酸树脂中的多元醇、多元酸、植物油类型,由此对改性醇酸树脂作结构鉴定。与直接裂解-气相色谱-质谱联用技术比较,具有样品前处理快速、简单,用量少,灵敏度高,定性准确,谱图直观等特点。     

气相色谱-质谱表征甲醇制烯烃副产汽油中的C5～C7烯烃

采用气相色谱-质谱(GC-MS)对甲醇制烯烃(MTO)副产汽油中的C5~C7烯烃进行了详细的定性表征,对MTO副产汽油中的49个单烯烃、11个二烯烃和9个环烯烃共计69个C5~C7烯烃组分在聚甲基硅氧烷柱上的保留指数进行了测定和定性确认。根据GC-MS定性分析结果建立了MTO副产汽油中C5~C7烯烃的保留指数数据库,采用气相色谱对副产汽油中C5~C7烯烃组分进行了定量分析。定量结果表明:MTO汽油以C5~C7脂肪族烯烃为主,含有少量的二烯烃和环烯烃,烷烃和环烷烃含量很少。MTO副产汽油中C5~C7烯烃的详细表征为其综合利用提供了依据。     

废弃印刷电路板材料裂解产物的高分辨裂解气相色谱-质谱分析

采用高分辨裂解气相色谱-质谱法(PyGC-MS)分析了FR-4型印刷电路板粉末样品的裂解产物。在氦气氛围中,分别在350,450,550,650和750 ℃下对印刷电路板粉末样品进行热裂解,并通过毛细管气相色谱-质谱对裂解产物进行分析,研究了不同裂解温度下裂解产物分布以及主要裂解产物的产率与裂解温度的关系,根据热分解产物的组成,探讨了热分解反应机理。     

Comparison of EI and metastable atom bombardment ionization for the identification of polyurethane thermal degradation products

Polyurethanes are widely used in the manufacture of commercial products such as foams and paints. During combustion, these polymers can generate isocyanates, which induce adverse health effects. Polymer pyrolysis (Py) hyphenated with mass spectrometry (MS) allows the investigation of polymer thermal degradation over time/temperature. A diphenylmethanediisocyanate (MDI) polyurethane foam was analyzed with electron ionization (EI) and metastable atom bombardment (MAB) ionization at a pyrolysis temperature of 400 °C. The recently introduced MAB ionization source uses discrete energy stored in metastable atoms of gases to ionize the analytes. This characteristic allows modulation of the ionization energy by simply changing the ionization gas. The extensive fragmentation of molecular ions observed using EI 70 eV is not totally eliminated with EI 10 eV. However, only molecular ions are observed with MAB using N₂ as the ionization gas. Temperature gradients were used to separate the products generated during the thermal degradation of a 1,6-hexamethylenediisocyanate (HDI) polyurethane paint. The analysis of mass spectra was facilitated owing to a selective desorption of pyrolysis products. Furthermore, changing the MAB ionization gas allows elucidation of the structure of the pyrolysis products by controlling the extent of their fragmentation. During these experiments, isocyanic acid, methyleneisocyanate, ethyleneisocyanate, propylisocyanate and butylisocyanate were detected.     

碳五馏分组分的HP-1毛细管色谱法测定

提出用ＨＰ－１毛细管色谱柱分析测定碳五馏分中组分含量的分析方法,研究了其测定条件,并对分离后的组分用质谱方法进行定性,按确定的分析条件,碳五馏分中各组分得到较好的分离,精密度好,分析结果准确可靠。     

One-dimensional and comprehensive two-dimensional gas chromatography coupled to soft photo ionization time-of-flight mass spectrometry: a two- and three-dimensional separation approach

Soft laser photo-ionization mass spectrometry is presented as a separation dimension hyphenated with gas chromatographic techniques. Single photon ionization (SPI) is a universal soft ionization method which ionizes organic molecules with an ionization potential below 10.5 eV if 118 nm laser radiation is used. The inherently soft ionization of photo ionization techniques can further be utilized together with gas chromatography as a comprehensive two-dimensional separation method (GC x MS), using the GC retention time as first separation dimension and the molecular mass as second separation dimension. Some GC x MS chromatograms of diesel petroleum samples using SPI are presented and discussed. Finally, it is demonstrated that the coupling of soft SPI mass spectrometry with comprehensive two-dimensional gas chromatography (GC x GC) provides a three-dimensional separation technique (GC x GC x SPI-MS).     

Non‐polar lipids characterization of Quinoa (Chenopodium quinoa) seed by comprehensive two‐dimensional gas chromatography with flame ionization/mass spectrometry detection and non‐aqueous reversed‐phase liquid chromatography with atmospheric pressure chemical ionization mass spectrometry detection

A chemical characterization of major lipid components, namely, triacylglycerols, fatty acids and the unsaponifiable fraction, in a Quinoa seed lipids sample is reported. To tackle such a task, non‐aqueous reversed‐phase high‐performance liquid chromatography with mass spectrometry detection was employed. The latter was interfaced with atmospheric pressure chemical ionization for the analysis of triacylglycerols. The main triacylglycerols (>10%) were represented by OLP, OOL and OLL (P = palmitoyl, O = oleoyl, L = linoleoyl); the latter was present in the oil sample at the highest percentage (18.1%). Furthermore, fatty acid methyl esters were evaluated by gas chromatography with flame ionization detection. 89% of the total fatty acids was represented by unsaturated fatty acid methyl esters with the greatest percentage represented by linoleic and oleic acids accounting for approximately 48 and 28%, respectively. An extensive characterization of the unsaponifiable fraction of Quinoa seed lipids was performed for the first time, by using comprehensive two‐dimensional gas chromatography with dual mass spectrometry/flame ionization detection. Overall, 66 compounds of the unsaponifiable fraction were tentatively identified, many constituents of which (particularly sterols) were confirmed by using gas chromatography with high‐resolution time‐of‐flight mass spectrometry.     

气相色谱-质谱法测定大蒜挥发油的组成

采用改进的水蒸汽蒸馏法从山东金乡大蒜中提取挥发油。实验确定了气相色谱-质谱法分析大蒜油的条件,并对大蒜挥发油的化学成分进行了定性分析,共鉴定出20种物质。用峰面积归一化法对各物质的相对含量进行了测定,结果表明含硫化合物约占挥发油总成分的95%以上,其中含量最高的是大蒜新素,约占挥发油总量的三分之一。对低温储藏半年的挥发油进行分析的结果表明样品在低温下可稳定存放。     

Characterization of complex hydrocarbons in cigarette smoke condensate by gas chromatography-mass spectrometry and comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry

Gas chromatography-mass spectrometry with electron ionization and positive-ion chemical ionization and comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry (GC x GC-TOF-MS) were applied for the characterization of the chemical composition of complex hydrocarbons in the non-polar neutral fraction of cigarette smoke condensates. Automated data processing by TOF-MS software combined with structured chromatograms and manual review of library hits were used to assign the components from GC x GC-TOF-MS analysis. The distributions of aliphatic hydrocarbons and aromatics were also investigated. Over 100 isoprenoid hydrocarbons were detected, including carotene degradation products, phytadiene isomers and carbocyclic diterpenoids. A total of 1800 hydrocarbons were tentatively identified, including aliphatic hydrocarbons, aromatics, and isoprenoid hydrocarbons. The identified hydrocarbons by GC x GC-TOF-MS were far more than those by GC-MS.     

红霉素类抗生素的自身化学电离质谱研究

采用自身化学电离离子化(SCI)/四极质谱法,测定了5个红霉素类抗生素,不仅得到了丰度较高的准分子离子(MH)^+,而且也得到了丰富的碎片离子,并对其裂解规律进行了总结。结果表明对于在电离过程中不稳定的化合物,SCI/四极质谱法既可确定其分子量,也可提供丰富的分子结构信息。此方法简便、快速,且图谱简单有助于结构分析。     

谱图检索结合二级质谱定性分析烟草中挥发性成分

采用同时蒸馏萃取法提取烟叶中的挥发性成分,利用气相色谱-质谱联用仪(GC-MS)分离测定,通过谱库检索和匹配度定性结合色谱保留指数方法鉴定烟叶中挥发性成分,并引入离子阱二级质谱对谱库检索匹配度差距小、含量低,背景干扰大的物质准确定性.采用谱图检索结合二级质谱定性共鉴定144个化合物,其中104个化合物在烟草挥发性成分的文献中已有报道,报道中有9个化合物是通过二级质谱定性,其余40个化合物还未见报道.结果表明,离子阱二级质谱定性的引入提高了对未知化合物定性的准确性和可靠性,适合于烟叶这类复杂植物体系的化学组分研究.     

纳秒强光场下呋喃的激光电离中高价离子的产生

The photo ionization of furan by an intense 25 ns Nd:YAG 532 nm laser has been studied by time-of-flight mass spectrometry. At the laser intensity of 1010～1011 W/cm2, multi-charged ions Can+ (n=2～4) and Ohm+ (m=2～3) appeared in the mass spectra when argon was used as the carrier gas. From the peak splitting and the numeric analysis, the most probable kinetic energies of C2+, C3+ and C4+ were confirmed to be 21、63 and 100 eV respectively, and the most probable kinetic energies of O2+ and O3+ were confirmed to be 20 and 40 eV respectively. It is proposed that the multi-charged ions come from the Coulomb explosion of furan cluster ions produced by multi photon ionization of neutral furan cluster.