气相色谱-质谱法测定苹果中多效唑残留量

苹果样品中的多效唑用丙酬-乙酸乙酯提取,弗罗里硅土柱净化后,用气相色谱-质谱电子轰击源正离子方式进行测定,外标法定量、通过监测离子的相对丰度对阳性结果进行确证。空白苹果样品中添加量在0．02～0．5mg／kg范围时,回收率达到90％～98％,相对标准偏差5．0％～8．6％,检出限为0．02mg／kg。     

凝胶渗透色谱净化一气相色谱分离同时测定糙米中50种有机磷农药残留

研究了同时检测糙米中50种有机磷农药残留的方法。用乙酸乙酯提取，凝胶渗透色谱净化，环己烷-二氯甲烷(50：50，V/V)作为流动相，气相色谱-氮磷检测器检测。方法检出限为0．001～0．089mg／kg；相对标准偏差为1．7％～18．9％；40多种农药平均回收率在70％～120％。     

气相色谱质谱联用法对农产品中8种种衣剂农药残留的同时测定

应用气相色谱-质谱联用仪（GC-MS）建立了水果、蔬菜、粮谷等农产品中8种种衣剂农药残留的分析测定方法。样品用乙腈提取,通过石墨化碳或C18固相萃取小柱净化,经DB-5ms气相色谱柱分离,电子轰击电离（EI）、选择离子监测模式（SIM）对定量离子和定性离子进行MS测定。标准工作曲线范围0．02-0．5mg／L。样品中添加水平为0．005、0．010和0．020mg／kg时,回收率为74％～110％;相对标准偏差小于15％。检出限（S／N=3）为0．09～0．77μg／kg。     

QuEChERS-气相色谱-串联质谱法同时测定银耳中17种杀虫剂残留

建立了QuEChERS-气相色谱-串联质谱法测定银耳中17种杀虫剂残留的分析方法。样品经乙酸乙酯+正己烷(50+50,V/V)提取,采用500 mg无水MgSO_4、150 mg乙二胺-N-丙基硅烷(PSA)、50 mg石墨化炭黑(GCB)吸附净化,以SH-Rxi-5Sil MS毛细管柱(30 m×0.25 mm×0.25μm)分离,质谱在多反应监测(MRM)模式下进行检测,外标法定量。结果显示:目标物在5.0～100.0μg/L范围内线性良好(R~20.995);在10μg/kg、20μg/kg、50μg/kg 3个添加水平下的回收率为92.0%～108.3%,相对标准偏差(RSD,n=6)为2.45%～11.23%,检出限为0.06～1.50μg/kg,定量限为0.20～5.00μg/kg。该方法准确、稳定,可以满足实际银耳样品中17种目标杀虫剂残留的分析需求。     

气相色谱-质谱同时测定猪肉中3种巴比妥药物残留

建立了固相萃取-气相色谱-质谱同时分析猪肉中3种巴比妥类药物残留量的方法。对猪肉样品的乙腈提取、C18固相萃取柱净化和碘甲烷甲基化条件进行了优化。采用HP-5毛细管柱分离,电子轰击电离源质谱选择离子模式(SIM)检测(巴比妥m／z126,169,183,184;异戊巴比妥m／z169、170、184、226;苯巴比妥m／z175、232、245、260;dwell time80s),外标法定量(定量离子m／z分别为169、169和232)。3种巴比妥药物的添加标准曲线线性回归系数均在0．99以上;线性范围2．5～50μg/kg,回收率为65％～112％,相对标准偏差5．4％～17．2％,检出限均为1μg/kg。     

气相色谱-串联质谱法测定涂料中10种苯并三唑类紫外线吸收剂

建立了涂料中10种苯并三唑类紫外线吸收剂的气相色谱-串联质谱(GC-MS/MS)检测方法。水性涂料和溶剂型涂料样品风干成膜后分别以正己烷、乙腈超声提取,DB-5色谱柱(30 m×0. 32 mm×0. 25μm)分离,MRM模式进行分析检测。结果表明,10种苯并三唑类紫外线吸收剂在0. 1～10μg/m L范围内与峰面积呈线性关系,方法的检出限(S/N=3)为0. 6 mg/kg,定量下限(S/N=10)为2. 0 mg/kg,在2、20、200 mg/kg加标浓度下的回收率为71. 6%～112%,相对标准偏差(RSD,n=6)不大于5. 5%。该方法快速简便、准确可靠,适用于涂料中苯并三唑类紫外线吸收剂的日常分析检测。     

气相色谱-负化学源质谱联用法测定菊酯类农药

通过固相萃取-气相色谱-负化学离子源质谱技术建立了11种拟除虫菊酯类农药残留的检测方法，并应用于茶叶农残检测。样品经乙酸乙酯提取后，用串联的活性炭和中性氧化铝固相萃取柱选择性地富集茶叶中待测组分，再由气相色谱-负化学离子源质谱分时段选择离子监测技术进行测定。方法简单快速，一次进样就能得到11种菊酯残留结果；准确度和精密度高，在0．016μg／kg、0．032μg／kg和0．064μg／kg3个添加水平下的回收率在70％～110％之间，CV≤7．4％；选择性好，消除了色素和其它杂质干扰；灵敏度高，检出限低，除了氯菊酯为10μg／kg外，其它菊酯检出限都在μg/∥kg级，七氟菊酯则达到了0．02μg／kg。     

气相色谱-质谱联用法在火药剖析中的应用

采用固液萃取的方法对火药样品进行处理,用气相色谱-质谱联用法对某未知火药进行成分剖析,以选择离子质谱法进行定量。目标化合物浓度在20-50mg／L范围内与色谱峰面积呈良好的线性关系,相关系数在0．9940～0．9996之间。方法加标回收率为96．9％～104.3％,测定结果的相对标准偏差为2．4％-4．9％（n=5）.气相色谱-质谱联用法可用于火药剖析研究。     

固相萃取-气相色谱法测定动物组织中盐酸克伦特罗残留量

建立了固相萃取-气相色谱分析动物组织中盐酸克伦特罗残留量的方法．采用固相萃取,分离富集动物组织中的盐酸克伦特罗．肉样的加标回收率在70％～80％;最低检出限为1μg／kg．盐酸克伦特罗的硅烷化衍生产物,采用气相色谱(ECD检测器)检测,其衍生物的峰面积与样品浓度在0．005～1．0μg／mL范围内呈良好的线性关系,线性回归系数大于0．999．     

溶剂萃取-毛细管气相色谱法测定烟草中主要生物碱

报道了用毛细管柱气相色谱同时测定烟草中尼古丁、去甲基尼古丁、新烟碱和去氢新烟碱4种主要生物碱的方法。烟草样品经二氯甲烷／甲醇(V/V,3：1)溶剂萃取,过一次性滤膜,直接进样,经HP-5MS毛细管柱分离,氮磷检测器(NPD)检测。该方法简单,重现性好;4种生物碱相对标准偏差为1．5％～3．4％;加标回收率为93．6％～102．4％。     

Study of the responses of a gas chromatography—reduction gas detector system to gaseous hydrocarbons under different conditions

The response of a reduction gas detector (RGD) to C₂-C₆ alkenes, C₂-C₆ alkanes, isoprene and benzene has been investigated using gas chromatography (GC) with a packed column. The RGD is considerably more sensitive to alkenes than is the flame ionization detector. The detection limit of this present GC/RGD system for alkenes is about 0.01 ng. It has much greater sensitivity to alkenes than to alkanes. Its sensitivity increases with increasing HgO bed temperature, but its selectivity towards alkenes decreases at the same time. The selectivity of the RGD may not be significant for much heavier molecules. The sensitivity of the RGD is inversely proportional to the carrier gas flow rate through the HgO bed. The baseline of the system increases significantly with increasing oven temperature.     

减肥保健品中芬氟拉明等8种合成食欲抑制剂的分析测定

建立了用气相色谱同时测定减肥保健品中芬氟拉明、苯丁胺 ,苄非他明、氯苯丁胺、氯苄苯丙胺、苯双甲吗啉、苯甲吗啉及安非泼拉酮等 8种合成食欲抑制剂的方法 ,检出限 <10 0 μg /L。分析结果用GC/MSD进一步确证 ,准确、可靠。     

气相色谱FID检测器常见故障及故障排除方法

介绍气相色谱FID检测器的结构特点、使用中常见故障及故障排除方法。     

High Pressure Liquid Chromatography of Selected Sulfur Compounds

Abstract

High pressure liquid chromatography was used to separate and determine quantitatively the following groups of sulfur compounds: thiols, sulfides, disulfides, sulfones, isothiocyanates, thioamides, and thioureas. Amperometric and UV detectors were compared; for thiols, thioureas, isothiocyanates, and thioamides, the former was generally more sensitive. With the exception of alkyl and cycloalkyl sulfides, the liquid chromatographic method can be used for the analysis of the investigated sulfur compounds below the ppm range. The method developed was compared to gas chromatography with flame photometric detection. The latter was found to be superior for the analysis of alkyl and cycloalkyl thiols, sulfides and disulfides of molecular weight below 200, whereas the former was more suitable for the analysis of aromatic thiols, sulfides and disulfides, as well as thioamides, isothiocyanates, and thioureas. Both methods were equivalent for the analysis of aromatic sulfones.     

Pulsed discharge helium ionization detector

Summary A pulsed discharge helium ionization detector (PDHID) (patent pending) for gas chromatography has been developed. This detector uses a non-radioactive pulsed high voltage discharge source for generation of electrons and pulsed collection of these electrons. We have evaluated this detector for the analysis of a wide range of chemical compounds. In this paper the analytes are passed through the discharge since the permanent gases are difficult to ionize. The initial results for the permanent gases indicate that the PDHID can be used as a universal detector of contaminant traces at detection levels on the order of 1–20 pg. The response in this mode of operation is linear over four orders of magnitude.Dedicated to Professor Leslie S. Ettre on the occasion of his 70th birthday.     

气相色谱法测定天然气中的硫化物

用气相色谱法,选择脉冲火焰光度检测器（PFPD）,在甲基硅油毛细管色谱柱上分析天然气中的硫化物。该方法灵敏度高,选择性好,结果准确,相对标准偏差小于1.1%。     

关于气相色谱仪检定的几个问题

在对气相色谱仪进行检定的过程中,遇到了有关色谱柱,标准样品,积分仪和色谱数据工作站数据采集等实际问题,为了既不影响生产工艺分析任务的进行,又能及时完成对仪器性能的检定工作,采取了相应的措施和办法,较快地完成了对气相色谱仪的检定,并对某些测试数据进行了比较和讨论。     

猪油样品中有机锡化合物的气相色谱-火焰光度法及气相色谱-质谱联用分析

通过将污染猪油中的有机锡化合物进行丙基化衍生后,利用气相色谱－ 火焰光度法（GC－FPD）及毛细管气相色谱－质谱联用（GC－MS）对它们作了全面的定性分析。实验结果表明：猪油样品中均含有二甲基锡,多数样品中还含有三甲基锡和一甲基锡。     

Determination of anthraquinone in a photometric detector

Anthraquinone can be determined, following gas chromatographic separation, by photometry of its luminescence in excited nitrogen. The spectrum consists of some broad bands, the most prominent of which peak at 460–480 nm. The minimum detectable amount (S/N=2), using a packed column, is surprisingly low at ca. 0.5 pg or 0.24 fmol/s (2.4×10^–16mol/s); the linear range spans three to four orders of magnitude; and the detector is capable of operating under temperature-programmed GC conditions.While anthraquinone is the strongest responding analyte of its kind, similar though somewhat weaker responses are produced by certain types of aroyl compounds. All other tested groups of organics give only extremely weak, negative responses (decreases in background luminescence) at some 10⁵ to 10⁶ higher concentrations. Quenching of anthraquinone luminescence can occur: As a typical example, a 50% reduction in response is produced by a ca. 100 ppmv/v level of co-elutingn-butane in the nitrogen carrier (a more than millionfold weight excess for a 1 pg peak of anthraquinone).Material taken from the Ph. D. thesis of Y.-Z. Tang (Dalhousie University, 1987)