轻质烃类中微量甲醇、甲基叔丁基醚等含氧化合物的测定

在乙烯厂生产中微量含氧化合物的测定非常重要,含氧化合物的存在可引起催化剂中毒,致使生产不能长周期运行。对乙烯、丁烯-1中含氧化合物的测定已有报道。但随着仪器和数据处理设备的更新有些缺陷就显现出来。近年来,毛细管色谱柱在含氧化合物的测定上也得到应用,但所使用的极性柱对甲醇、甲基叔丁基醚（MTBE）等含氧化合物分析时常有C3,C4和C5等烃类的干扰,在分析实际样品时会有合峰出现,无法得到准确结果。本文采用超强极性的LOWOX色谱柱,可以排除轻质烃类的干扰,降低检出限。     

气相色谱-质谱法测定甲基叔丁基醚中共存化合物的含量

用DB-624毛细管色谱柱分离了由甲醇和丁烯混合物反应所生成的甲基叔丁基醚(以下简写作MtBE)共存的杂质化合物,并用气相色谱-质谱联用法予以鉴别和测定。测定中采用峰面积归一化法,总共测得包括MtBE本身在内的66种化合物,并给出了它们的相对含量。并对其中部分杂质化合物的形成机理也作了探讨。     

液液萃取结合分散固相萃取-液相色谱串联质谱检测食品包装纸中的4-氨基偶氮苯

采用高效液相色谱-串联质谱法（LC-MS/MS）快速测定食品包装纸中偶氮染料释放的4-氨基偶氮苯.试样在0.5 mol/L氢氧化钠溶液的碱性环境下,用连二亚硫酸钠还原试样中的偶氮染料,用甲基叔丁基醚反萃取还原裂解产生的4-氨基偶氮苯,经氮吹、甲醇复溶后,用液相色谱-串联质谱进行测定,内标法定量.方法优化了色谱分离、质谱、液液萃取和分散固相萃取等条件.最优化条件下方法的检出限为0.13 mg/kg,定量限为0.42 mg/kg,加标回收率在90%~95%之间（添加水平分别为1、10、30 mg/kg）,相对标准偏差小于5%.     

利用大口径毛细管气相色谱法测定液化气中的含硫化合物

利用大口径毛细管色谱柱、不分流进样、氢焰离子化检测器（ＦＩＤ）、双火焰光度检测器（ＤＦＰＤ）,与气相色谱－质谱（ＧＣ－ＭＳ）联用技术相结合,对脱硫后的液化气进行测定,成功地鉴定出１７种含硫化合物。该法简便、快速,对含硫化合物的检测灵敏度高。     

气相色谱法测定车用汽油中含氧化合物和苯胺类化合物

利用中心切割技术和双毛细管色谱柱系统,采用两次进样的方式,建立了气相色谱测定车用汽油中含氧化合物和苯胺类化合物的分析方法。第一次进样分析,组分首先进入非极性DB-1色谱柱(30 m×0.32 mm×1.0μm),按沸点由低到高的顺序分离,通过电磁阀切换将沸点小于2-己酮的组分切割至强极性GS-OxyPLOT色谱柱(10 m×0.53 mm×10μm)或CP-Lowox色谱柱(10 m×0.53 mm×10μm),其余重烃组分通过阻尼柱进入FID检测器。在GS-OxyPLOT或CP-Lowox色谱柱上,烃类组分与含氧化合物分离并进入检测器检测,消除了大量的烃类组分对含氧化合物测定的影响。第二次进样分析,设定电磁阀切换时间为间-甲基苯胺从非极性色谱柱流出的时间,苯胺类化合物在GS-OxyPLOT或CP-Lowox色谱柱上与烃类和含氧化合物分离并进入检测器检测。以乙二醇二甲基醚为内标化合物进行内标法定量。实现了在一套系统上同时测定车用汽油中添加的甲基叔丁基醚(MTBE)、甲醇、甲缩醛、乙酸仲丁酯、乙酸乙酯、苯胺、邻/间/对-甲基苯胺和N-甲基苯胺的含量,各组分的检测范围为0.01%~10%(质量分数),回收率为86.0%~102.6%。该法可以为车用汽油的质量控制提供有效的检测手段。     

超声萃取-气相色谱-质谱法检测塑料玩具中8种邻苯二甲酸酯类增塑剂

建立了气相色谱-质谱法（GC-MS）同时测定玩具中8种邻苯二甲酸酯化合物的方法.利用四氢呋喃提取塑料玩具中邻苯二甲酸酯化合物,超声提取30 min,经乙腈沉淀,采用GC-MS外标法进行定量检测.结果表明,8种邻苯二甲酸酯线性范围为0.5~10 mg/L,相关系数均大于0.995,方法检出限为1.14~13.65 mg/kg,平均回收率为89.2%~103.8%,相对标准偏差为1.41%~4.93%.方法简单、快速、准确,可用于塑料玩具中邻苯二甲酸酯的检测.     

离子色谱-积分脉冲安培法测定肉类产品中鹅肌肽、高肌肽及肌肽

建立了一种离子色谱-积分脉冲安培（IC-IPAD）同时测定肉类样品中鹅肌肽、高肌肽及肌肽的分析方法。方法采用高效阴离子交换色谱柱AminoPac PA10（250 mm×2 mm）分离,以100 mmol/L NaOH为淋洗液,流速为0.2 mL/min,柱温为30℃。结果表明,3种目标化合物在15 min内可实现完全分离,且17种氨基酸对3种目标化合物不存在干扰。在最佳色谱条件下,鹅肌肽、高肌肽及肌肽在0.05~5.0 mg/L范围内呈良好的线性关系,线性相关系数（r）>0.99。3种目标化合物的检出限和定量限分别为8.9~22.1 μg/L和29.6~73.6 μg/L。对鸭胸及鹅胸样品进行分析,加标回收率为92.4%~104.5%。该方法简单方便,无需衍生化,灵敏度高,可用于肉类产品中相关营养成分的测定。     

高效液相色谱法测定甲基化氨基酸及其相关化合物

本文提出一种用于测定甲基化氨基酸化合物的高效液相色谱方法。本法采用实验室组装的离子交换色谱分析仪和柱后衍生－荧光检测法，所有已知组氨酸、赖氨酸和精氨酸的天然衍生物均可完全分离测定，全部分离测定过程需时１１８ｍｉｎ，检测灵敏度可达皮摩尔级（１０￣（－１２）ｍｏｌ），方法重现性良好，本法已成功地用于遭受环境污染损害的云杉针叶中甲基化氨基酸化合物的分离测定。     

高效液相色谱-串联质谱法同时测定烟草中5种Amadori化合物

建立了高效液相色谱-三重四极杆质谱（HPLC-QqQ MS）联用定量分析烟草中5种Amadori前香物质的方法。样品经含5%（v/v）甲醇的水提取后,采用Waters XBridge^TM Amide色谱柱（250 mm×4.6 mm,3.5 μm）、以甲醇-水为流动相进行分离,采用多反应监测（MRM）模式测定烟草样品中5种Amadori化合物的含量。结果表明,5种Amadori化合物的峰面积与质量浓度的线性关系良好,相关系数r为0.9895~0.9989;定量限（S/N=10）在10.18~44.58 μg/L,检出限（S/N=3）在3.51~14.86 μg/L;平均加标回收率为92.6%~123.6%,相对标准偏差（RSD）小于9.4%。本方法操作简便、灵敏度高、分析速度快,可以用于烟叶及卷烟中5种主要Amadori类物质的含量测定。     

黄芪中黄酮类化合物的超临界流体色谱分离方法研究

考察了超临界流体色谱（SFC）中的色谱柱、改性剂、添加剂、流速、柱温和背压等因素对9种黄酮类成分（包括芒柄花素、异鼠李素、毛蕊异黄酮、山奈酚、槲皮素、紫云英苷、芒柄花苷、异槲皮苷、毛蕊异黄酮葡萄糖苷）分离的影响,与高效液相色谱法（HPLC）进行了比较,并建立了黄芪饮片中5种主要黄酮类化合物的SFC分析方法。采用Agilent ZORBAX RX－SIL色谱柱（4.6 mm × 150 mm,5 μm）进行分离,CO2－0.1%磷酸甲醇溶液为流动相梯度洗脱,流速为3 mL/min;柱温为35 ℃;背压为10 MPa,9种黄酮类化合物可在10 min内实现基线分离。5种黄酮类化合物在一定质量浓度范围内均具有良好的线性关系（r2 ≥ 0.963 2）,检出限为10.69 ~ 16.21 μg/mL,日内相对标准偏差（RSD）为1.3% ~ 2.0%;日间RSD为1.6% ~ 2.2%。5种黄酮类化合物在48 h内具有良好的稳定性,重复性为3.6% ~ 6.0%,回收率为91.8% ~ 112%。与HPLC法相比,9种化合物的保留时间顺序基本相反,SFC法更快速、经济环保,且其保留及选择性受色谱柱、改性剂和添加剂的影响较大,添加剂对色谱峰形影响明显。     

Determination of Oxygenates in Gasoline by GC×GC

Comprehensive two‐dimensional gas chromatography (GC×GC) has been applied to the quantitation of oxygenates in reformulated gasoline. Target oxygenates were C₁–C₄ alcohols, tert‐pentanol, methyl tert‐butyl ether (MTBE), diisopropyl ether (DIPE), ethyl tert‐butyl ether (ETBE), and tert‐amyl methyl ether (TAME). These were separated from the gasoline matrix using a volatility‐based selectivity in the first chromatographic dimension, followed by a mixed‐phase polarity/shape selectivity in the second dimension. The high resolving power of this stationary phase combination completely separated all oxygenates except DIPE, ETBE, and TAME, which exhibited coelution with other nonpolar gasoline components. Oxygenates quantitation was achieved with the use of an internal standard, an FID detector, and calibration curves. Quantitation results are in good agreement with ASTM and EPA standard methods. When coupled with our previous method for BTEX and aromatics, a single GC×GC method can now quantitate MTBE, alcohols, BTEX, and aromatics in a one‐hour analysis.     

Effects of Mobile Phase Ratios on the Separation of Plant Carotenoids by HPLC with a C30 Column

Plant products are dietary sources of lutein and zeaxanthin. Lutein and zeaxanthin have been implicated in the protection of age related macular degeneration (AMD) and in cardiovascular diseases. However, xanthophylls and unidentified components (λ_max = 423 and 468 nm) in plant products are often not separated well, and affect an accurate quantitative determination of lutein and zeaxanthin. A high performance liquid chromatography (HPLC) system equipped with a Bischoff C30 column and a mobile phase of methanol, methyl-tert-butyl ether (MTBE) and water was used to separate lutein, zeaxanthin and other unidentified components in plant products. Mobile phase A containing methanol, MTBE and water with a ratio of 60:33:7 by volume (1.5% ammonium acetate, NH₄Ac), combined with mobile phase B with a ratio of 8:90:2 by volume (1.0% NH₄Ac) is optimal for the separation. This method was successfully applied to the quantitative determination of lutein and zeaxanthin in extracts of plant products, such as chlorella, spirulina, celery and mallow.     

A new disposable ionic liquid based coating for headspace solid-phase microextraction of methyl tert-butyl ether in a gasoline sample followed by gas chromatography-flame ionization detection

A new ionic liquid (IL) based solid-phase microextraction (SPME) fiber was investigated and used for headspace (HS) extraction of methyl tert-butyl ether (MTBE) in a gasoline sample. Using the new IL coated HS-SPME fiber with the combination of gas chromatography-flame ionization detection (GC-FID); sub-to-low μg L⁻¹ concentrations of MTBE were detected. Four different ILs including 1-butyl-3-methylimidazolium tetraflouroborate ([C₄C₁IM] [BF₄]), 1-octyl-3-methylimidazolium tetraflouroborate ([C₈C₁IM] [BF₄]), 1-octyl-3-methylimidazolium hexaflourophosphate ([C₈C₁IM] [PF₆]) and 1-ethyl-3-methylimidazolium ethylsulphate ([C₂C₁IM] [ETSO₄]) were synthesized and examined for extraction, preconcentration and determination of MTBE. It was observed that [C₈C₁IM] [BF₄] showed the highest extraction efficiency and possessed the best extractability for MTBE. The fiber coating takes up the compounds from the sample by absorption in the case of liquid coatings. The calibration graph was linear in a concentration range of 1-120 μg L⁻¹ (R² > 0.994) with the detection limit of 0.09 μg L⁻¹ level. The new IL-coated fiber was applied successfully for the determination of MTBE in a gasoline sample with good recoveries between 90 and 95%.     

Liquid chromatographic analysis of the anticancer alkaloid luotonin A and some new derivatives in human serum samples

The quantitation of the natural cytotoxic and anti‐inflammatory alkaloid luotonin A and five recently synthesized derivatives is described, constituting the first report of a HPLC method for the analysis of these compounds in human serum samples. The conditions for the chromatographic separation were optimized and the method was validated for the analysis of these compounds in biological samples according to international guidelines. An RP‐HPLC method with fluorimetric detection and a C₁₈ stationary phase was applied. Different ACN/water mobile phases were assayed, including 0–4% of a mobile phase modifier such as tetrahydrofuran, dioxane or tert‐butyl methyl ether. Isocratic and gradient elution conditions are compared. The influence of pH on the efficiency and resolution of the separation was also considered. The developed method was applied to the determination of luotonins in pooled human serum samples by gradient elution RP‐HPLC using a simple cleanup procedure. The proposed chromatographic method exhibits satisfactory analytical figures of merit, with LOD from 1.0×10^?10 to 2.0×10^?10 M, intraday and interday precision below 6% except for the concentration level closest to LOD, and good agreement between experimental and theoretical concentrations. Therefore, the developed method is suitable, reliable, rapid, and simple.     

Coupling of solid‐phase microextraction with micellar desorption and high performance liquid chromatography for the determination of pharmaceutical residues in environmental liquid samples

A residue analytical method combining solid‐phase microextraction (SPME) with external micellar desorption (MD) and high‐performance liquid chromatography with diode array detector (HPLC‐DAD) has been developed and validated for the simultaneous determination of six pharmaceutical compounds, belonging to various therapeutic categories in water samples. Target compounds include antiinflamatory drugs (ibuprofen, ketoprofen and naproxen), an analgesic (phenazone), a lipid regulator (bezafibrate) and an antiepileptic (carbamazepine). A detailed study of the experimental conditions of extraction and desorption with different surfactants was performed in order to obtain the best results during instrumental analysis. Of the different fibers and surfactants investigated, 65 µm polydimethysiloxane‐divinilbenzene (PDMS‐DVB) fiber and polyoxyethylene 10 lauryl ether (POLE) and polyoxyethylene 6 lauryl ether (C₁₂E₆) as desorbing agents produced the optimal response to pharmaceutical residues. Recoveries obtained were generally higher than 80% and the variability of the method was below 16% for all compounds in both surfactants. Method detection limits were 0.05–12 ng mL^?1 for POLE and 0.1–5 ng mL^?1 for C₁₂E₆. The developed method was compared using external desorption with organic solvent and it was successfully applied to the determination of these pharmaceutical compounds in water samples from different origin. Solid‐phase microextraction with micellar desorption (SPME‐MD) represents a new approach for the extraction of different pharmaceutical compounds in natural waters because it combines shorter handling time, better efficiency, safety and more environmentally friendly process than the traditional methods. Copyright © 2009 John Wiley & Sons, Ltd.     

Chromatography-mass spectrometry and toxicity evaluation of selected contaminants in seawater

Summary In the present work a combined analytical study involving gas and liquid-chromatography and toxicity studies were developed for the determination of various contaminants typically present in sea water samples. The compounds investigated were Diuron, Chlorothalonil, Dichlofluanid, TCMTB (2-thiocyanomethylthiobenzothiazole), lrgarol 1051, Sea nine 211 and MTBE (methyl-tert-butyl ether). The selected compounds are additives of boat paints and gasoline and they can release into the aquatic environment in considerable amounts in areas with intense shipping traffic. The developed analytical protocol consisted on the use of a solid phase extraction procedure with Oasis^™ HLB cartridges followed by GC-El/NCI-MS and LC-ES-MS both in SIM mode. Average recoveries, loading 600 mL of samples with pH=3, varied from 40 to 95% and the detection limits ranged from 1–25 ng L⁻¹. The developed method was applied to real samples from various marinas of Andalusia (Spain).Daphnia magna, Vibrio fischeri andSelenastrum capricornotum toxicity bioassays on individual and mixtures of selected compounds were applied to evaluate EC₅₀ (effective concentration) and LOEC (lowest observable effect concentration) values. Resulting values were in the range of 0.001–720 mg L⁻¹ for EC₅₀ and 0.8.10⁻⁹–30 mg L⁻¹ for LOEC for all contaminants except for MTBE where no toxic effect were found up to 680 mg L⁻¹ onDaphnia magna. Toxicity effects of binary mixtures of the selected compounds showed synergistic effects in the majority of the cases (47.6%) and antagonistic in the lower of the cases (9.5%). Levels of the contaminants found in the seawater samples showed around a 30% of inhibition on tested species, during the summer months considering mixture lrgarol 1051-Diuron. Accelerated toxicity processes were observed in mixtures MTBE-Diuron and MTBE-Dichlofluanid. Presented in the Workshop “GPoll of European Science Foundation” Barcelona, Spain, 8–10 November 2001.     

Fast liquid chromatography-tandem mass spectrometry for the analysis of bisphenol A-diglycidyl ether, bisphenol F-diglycidyl ether and their derivatives in canned food and beverages

In this work a fast liquid chromatography coupled with tandem mass spectrometry (LC–MS/MS) method using a C18 Fused Core™ column, was developed for the simultaneous analysis of bisphenol A diglycidyl ether (BADGE), bisphenol A (2,3-dihydroxypropyl) glycidyl ether (BADGE·H₂O), bisphenol A bis(2,3-dihydroxypropyl) ether (BADGE·2H₂O), bisphenol A (3-chloro-2-hydroxypropyl) glycidyl ether (BADGE·HCl), bisphenol A bis(3-chloro-2-hydroxypropyl) ether (BADGE·2HCl) and bisphenol A (3-chloro-2-hydroxypropyl)(2,3-dihydroxypropyl ether) (BADGE·HCl·H₂O) and bisphenol F diglycidyl ether (BFDGE), bisphenol F bis(2,3-dihydroxypropyl) ether (BFDGE·2H₂O), bisphenol F bis(3-chloro-2-hydroxypropyl) ether (BFDGE·2HCl). The LC method was coupled with a triple quadrupole mass spectrometer, using an ESI source in positive mode and using the [M+NH₄]⁺ adduct as precursor ion for tandem mass spectrometry experiments. The method developed was applied to the determination of these compounds in canned soft drinks and canned food. OASIS HLB solid phase extraction (SPE) cartridges were used for the analysis of soft drinks, while solid canned food was extracted with ethyl acetate. Method limits of quantitation ranged from 0.13 μg L⁻¹ to 1.6 μg L⁻¹ in soft drinks and 1.0 μg kg⁻¹ to 4.0 μg kg⁻¹ in food samples. BADGE·2H₂O was detected in all the analyzed samples, while other BADGEs such as BADGE·H₂O, BADGE·HCl·H₂O, BADGE·HCl and BADGE·2HCl were also detected in canned foods.     

Fast detection of methyl tert-butyl ether from water using solid phase microextraction and ion mobility spectrometry

Methyl tert-butyl ether (MTBE) is commonly used as chemical additive to increase oxygen content and octane rating of reformulated gasoline. Despite its impact on enhancing cleaner combustion of gasoline, MTBE poses a threat to surface and ground water when gasoline is released into the environment. Methods for onsite analysis of MTBE in water samples are also needed. A less common technique for MTBE detection from water is ion mobility spectrometry (IMS). We describe a method for fast sampling and screening of MTBE from water by solid phase microextraction (SPME) and IMS. MTBE is adsorbed from the head space of a sample to the coating of SPME fiber. The interface containing a heated sample chamber, which couples SPME and IMS, was constructed and the SPME fiber was introduced into the sample chamber for thermal desorption and IMS detection of MTBE vapors. The demonstrated SPME-IMS method proved to be a straightforward method for the detection of trace quantities of MTBE from waters including surface and ground water. We determined the relative standard deviation of 8.3% and detection limit of 5 mg L⁻¹ for MTBE. Because of short sampling, desorption, and detection times, the described configuration of combined SPME and IMS is a feasible method for the detection of hazardous substances from environmental matrices.     

Gas-chromatographische Spurenbestimmung von C1- und C2-Fluor- und Chlorkohlenwasserstoffen in Luft

Zusammenfassung Als Beitrag zur Untersuchung des viel diskutierten Ozonabbaus wurde eine Analysenmethode zur quantitativen Bestimmung von CCl₄ (R10), CFCl₃ (R11), CF₂Cl₂ (R 12), CHCl₃, CH₃-CCl₃, C₂HCl₃ und C₂Cl₄ ausgearbeitet. Geeignete Methoden der Probenahme, Anreicherung, Detektion und der gesamten gas-chromatographischen Technik ermöglichen Bestimmungen in ppb-Bereich (10^–9 V/V) und ppt-Bereich (10^–12 V/V) bis herab zur Nachweisgrenze, die für alle genannten Verbindungen bei 10 ppt (V/V) liegt, u. U. auch darunter. Im Spurenbereich 100 ppt (V/V) werden eine Genauigkeit von < 10% und eine Reproduzierbarkeit von < 5 % erreicht, wenn die Untersuchung unmittelbar oder wenigstens innerhalb von 2 Tagen nach der Speicherung durchgeführt wird. Ist dies nicht möglich, wird ein besonderes Gas-Sammelgefäß verwendet, von dem aus in das Speicherrohr übergeführt werden kann.

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Gas-chromatographic determination of traces of C₁- and C₂-fluoro- and chlorohydrocarbons in air

Summary As a contribution to the frequently discussed ozone decomposition an analytical method has been elaborated for the quantitative determination of CCl₄, CFCl₃, CF₂Cl₂, CHCl₃, CH₃-CCl₃, C₂HCl₃, and C₂Cl₄. Suitable methods of sampling, enrichment, detection, and the whole gas-chromatographic operation allow determinations in the ppb range (10^–9 V/V) and the ppt-range (10^–12 V/V) down to the limit of detection at 10 ppt for all the cited compounds. For trace amounts of 100 ppt, an accuracy of < 10% and a reproducibility of < 5 % are reached if the determination is carried out immediately or at least 2 days after storage. If this is impossible, a special gassampling vessel is employed from which the sample is transferred to the storage column.

Herrn Prof. Hartmann zum 65. Geburtstag gewidmet     

PAHs Formation in the Depositions in a Methyl tert-Butyl Ether/Ar,a Methyl tert-Butyl Ether/O2/Ar and a Methyl tert-Butyl Ether/H2/Ar RF Plasma Environment

Contents and distributions of polycyclic aromatic hydrocarbons (PAHs) in the depositions were investigated and discussed in a MTBE/Ar, a MTBE/O₂/Ar and a MTBE/H₂/Ar plasma systems. A radio-frequency (RF) plasma system was used to produce the depositions under the designed operational condition. The identification and quantification of PAHs was accomplished by using a GC with a mass selectivity detector (GC/MS). Results indicated that when the input power controlled at high wattage (70 W) in the three systems, the contents of total-PAH in the MTBE/Ar system are higher than those of total-PAH in other system with adding O₂ or H₂. The comparison of three systems indicated the formation and accumulation of PAHs in the MTBE/Ar system is easier than other systems. At high input power wattage, when the MTBE/Ar mixture added O₂ or H₂, the domain pattern was shifted from both 3- and 4-ring PAH to 2-ring PAH. As far as the total-PAH content is concerned, the MTBE/Ar system at 70 W was found to have the highest mean total-PAH content (1540 g/g), while the MTBE/O₂/Ar system at 20 W had the lowest mean total-PAH content (44.4 g/g).