Determination of siloxanes,silicon, and platinum in tissues of women with silicone gel-filled implants

Silicone [poly(dimethylsiloxane)] gel used in breast implants has been known to migrate through intact silicone elastomer shells, resulting in the clinically observable "gel bleed" on the implant surface. Although silicon concentrations in capsular tissues of women with silicone prostheses have been measured with element-specific silicon analyses, no silicone-specific investigation of these tissues has been performed as yet.A combination of element-specific inductively coupled plasma high-resolution isotope dilution mass spectrometry (ICP-HR-IDMS) and species-specific gas chromatography coupled mass spectrometry (GC-MS) was used to analyze silicon, platinum, and siloxanes in prosthesis capsule, muscle, and fat tissues of women (n=3) who had silicone gel-filled breast implants and in breast tissue of non-augmented women (n=3) as controls.In all tissues of augmented women, siloxanes, in particular octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5), and dodecamethylcyclohexasiloxane (D6) were identified. Depending on the siloxane species and type of tissue analyzed, siloxane levels in the range of about 10-1,400 ng g(-1) were detected; total silicon was found in all tissue samples in the range of about 8,900-85,000 ng g(-1). Higher platinum levels ranging from 25-90 ng g(-1 )were detected in fibrin layer and fat tissue of two patients with prostheses. No siloxanes were detected in control breast tissue samples.This investigation of human tissues by a combination of element-specific and species-specific analytical techniques clearly demonstrates for the first time that platinum and siloxanes leak from prostheses and accumulate in their surrounding tissues.     

Determination of cyclic and linear siloxanes in soil samples by ultrasonic-assisted extraction and gas chromatography-mass spectrometry

A rapid method, based on sonication-assisted extraction in small columns (SAESC) and subsequent quantification and identification by gas chromatography-mass spectrometry (GC-MS), was developed for the determination of cyclic and linear siloxanes in soil. In the experiments with spiked samples (10-50 ng g(-1)), the recovery of cyclic and linear siloxanes ranged from 87.7 to 108.0% and from 84.9 to 107.6%, respectively. The validated method was used to determine the levels of these compounds in various types of soil samples collected from different locations in Spain. The cyclic siloxanes, decamethylcyclopentasiloxane (D5) and dodecamethylcyclohexasiloxane (D6) were detected in all the soil samples analyzed at concentrations from 9.2 to 56.9 ng g(-1) for D5 and from 5.8 to 27.1 ng g(-1) for D6 in agricultural soils and from 22 to 184 ng g(-1) for D5 and from 28 to 483 ng g(-1) for D6 in industrial soils. The total linear siloxanes concentrations (L5-L14) (sum of the 10 congeners) ranged from 191 to 292 ng g(-1) in agricultural soils and from 1411 to 8532 ng g(-1) in industrial soils.     

Rapid simultaneous determination of multiple pesticide residues in traditional Chinese medicines using programmed temperature vaporizer injection-fast gas chromatography coupled with mass spectrometry

A fast gas chromatography coupled with mass spectrometry (GC-MS) using large volume injection with programmed temperature vaporizer in solvent vent mode (PTV-LVI-SV) was developed for the trace determination of multiple pesticide residues in traditional Chinese medicines (TCMs). Experimental conditions of PTV-LVI-SV injection were optimized by central composite design. The optimized result was that initial temperature was held at 40°C for 39 s, vent flow rate was set at 45 mL/min and vent pressure was held at 0 psi for 36 s, injection volume was 10 μL. Furthermore, the quick and effective QuEChERS (quick, easy, cheap, effective, rugged and safe) method was performed to extract and purify pesticide residues in TCMs. The prepared samples were analyzed with GC-MS in the selected ion monitoring mode (SIM). The lowest LOD was 4 μg/kg for some pesticides. The recoveries were checked by spiking samples with pesticides at 25, 50 and 250 μg/kg. The average recoveries of most pesticides were from 80 to 118%. The result indicated that QuEChERS and PTV-LVI-SV GC-MS method was a rapid and sensitive analysis technique for the determination of multiple pesticide residues in TCMs.     

Understanding the impact of silicon compounds on metallic catalysts through experiments and multi-technical analysis

The presence of silicon in petroleum products is a major issue due to its poisoning effect on catalysts. The aim of this work is to combine silicon speciation and poisoning tests. Cyclic siloxanes were the main silicon species found in petroleum products. Other silicon compounds, comprising reactive groups (hydroxy, methoxy and hydroperoxy), were also recovered but at trace levels using GC-ICP/MS. Five well-chosen silicon compounds were used to poison Pd/alumina catalysts. Only dimethoxydimethylsilane poisons Pd-catalysts while polydimethylsiloxane (PDMS) has no effect on their activities in buta-1,3-diene hydrogenation. Unexpectedly, triethylsilane, triethylsilanol and even octamethylcyclotetrasiloxane (D₄) exhibit a promoting effect. An interpretation of the phenomena based on various characterizations is proposed.     

分散固相萃取-气相色谱-质谱联用法测定水产品中的痕量酮麝香

建立了水产品中痕量酮麝香测定的分散固相萃取-气相色谱-质谱联用法(GC-MS)。目标化合物经1%乙酸-乙腈高速匀浆提取,以N-丙基乙二胺(PSA)、C₁₈和石墨化碳(GCB)混合物为分散剂对其进行净化,采用GC-MS在选择离子监测模式下测定,外标法定量,并应用正交试验对前处理条件进行优化,以及对酮麝香的裂解机制进行探讨。在优化条件下,方法在1～50 μg/L范围内线性关系良好,相关系数不低于0.999,检出限(S/N=3)为0.30 μg/kg。对于明虾和罗非鱼空白样品,在1.0、2.0、10.0 μg/kg 3个水平下的加标回收率为91.8%～110.6%,相对标准偏差(RSD)为2.6%～8.4%。该方法操作简便、快速、准确,可用于水产品中痕量酮麝香的日常检验。     

气相色谱-质谱法测定鸡肉组织中残留的氯羟吡啶

建立了气相色谱-质谱(GC-MS)测定鸡肉组织中氯羟吡啶残留的确证方法。采用乙腈提取鸡肉组织中的待测物,经碱性氧化铝层析柱净化,Sylon BFT衍生剂衍生后,采用选择离子监测(SIM)模式检测。对氯羟吡啶三甲基硅烷化衍生物的电子轰击（EI）质谱碎片进行解析,选择m/z 212,214,248和263等4个特征离子作为定性离子,其中m/z 248为定量离子。同时还考察了检测过程中的基质效应。氯羟吡啶衍生物的响应与其质量浓度在5.0～500 μg/L范围内呈良好的线性关系,相关系数大于0.998;以3倍信噪比(S/N)计算方法的检出限达0.5 μg/kg;在5,10和20 μg/kg添加水平下鸡肉组织中待测物的平均回收率分别为77.0%,84.5%及89.4%,相对标准偏差小于6.9%。结果表明,该方法简单、灵敏、可靠,适用于鸡肉组织中氯羟吡啶残留的分析确证。     

Simplified and rapid determination of polychlorinated biphenyls, polybrominated diphenyl ethers, and polycyclic aromatic hydrocarbons in fish and shrimps integrated into a single method

In this study, a new rapid and flexible method for the simultaneous determination of 18 key representatives of polychlorinated biphenyls (PCBs), 7 polybrominated diphenyl ethers (PBDEs), and 32 polycyclic aromatic hydrocarbons (PAHs) in fish and shrimps by gas chromatography coupled to mass spectrometry (GC-MS) was developed and validated. A substantial simplification of sample processing prior to quantification step was achieved: after addition of water to homogenized sample, transfer of hydrophobic analytes into ethyl acetate was supported by added inorganic salts. Bulk fat, contained in crude organic extract obtained by partition, was subsequently removed on a silica minicolumn. This approach enabled to process six samples in less than 1h; moreover, the volume of an extraction solvent and consumption of other chemicals can be significantly reduced compared to, e.g., traditional Soxhlet extraction followed by gel permeation chromatography. The recoveries of target analytes were in the range of 73-120% even at the lowest spiking level (1 μg kg(-1)), repeatabilities (relative standard deviations, RSDs) ranged from 1 to 20%. Under optimized GC-MS conditions (time-of-flight mass analyzer, TOF), the limits of quantification (LOQs) were as follows: PCBs 0.1-0.5 μg kg(-1), PBDEs 0.5 μg kg(-1), and PAHs 0.05-0.25 μg kg(-1). Ambient mass spectrometry employing a direct analysis in real time (DART) ion source was shown as an effective tool for fat control in extract, which is needed during the method development and examination of unknown samples prior to the analysis. Further extension of a method scope by other similar analytes is easily possible.     

GC-MS法测定植物提取物中19种邻苯二甲酸酯类化合物

建立了植物提取物中19种邻苯二甲酸酯类化合物(PAEs)的气相色谱-质谱(GC-MS)分析方法。样品经水溶解,正己烷提取,弗罗里硅土小柱净化,采用GC-MS法在选择离子监测模式(SIM)下进行测定。结果表明:方法在0.1～10 mg/kg范围内具有良好的线性关系,相关系数均大于0.999,检测限为0.14～1.2μg/kg,加标回收率为62.1%～118.2%,相对标准偏差为0.61%～13%。方法可满足植物提取物中PAEs的定性和定量测定。     

多次溶剂萃取-气相色谱/串联质谱法测定热熔胶中的多环芳烃

建立了热熔胶中16种多环芳烃( PAHs)的多次溶剂萃取-气相色谱/串联质谱测定方法。详细研究了样品的萃取条件、净化条件和气相色谱/串联质谱测定条件,并与气相色谱-质谱法进行了对比。样品以10 mL正己烷为萃取溶剂,于60℃超声萃取20 min,萃取液依次经冷冻后离心、二甲基亚砜萃取2次、正己烷反萃取2次进行净化,得到的净化液以气相色谱/串联质谱法多反应监测( MRM)模式进行检测。本方法的线性相关系数( R2)均大于0.9969,检出限为1.0~10μg/kg,精密度小于6.3%,16种PAHs的加标回收率为80.4%~117.6%。考察了串联质谱检测的基质效应,发现基质效应不明显。本方法检出限优于气相色谱-质谱法(23~94μg/kg),并能增加定性和定量分析的准确性。本方法灵敏、准确可靠,满足热熔胶中PAHs测试要求。     

正化学源-气相色谱-质谱法测定食用植物油中有机锡化合物残留

建立了正化学源-气相色谱-质谱技术测定食用植物油中有机锡化合物残留的方法。食用油样品经环己烷-乙酸乙酯（1：1，v/v）溶解后，经凝胶渗透色谱（GPC）净化，目标馏分用四乙基硼酸钠进行衍生。采用基质校正曲线外标法定量，在20~2000 μg/L范围内，7种有机锡化合物均呈现良好的线性关系，相关系数大于0.99，定量限为0.3~1.2 μg/kg。对芝麻油样品进行加标回收试验，在0.05、0.10、0.20 mg/kg 3个添加水平下，7种有机锡化合物的平均回收率为66.2%~103.2%，相对标准偏差均小于11.5%。该方法精密度好，灵敏度高，可用于食用植物油中有机锡化合物残留量的测定。     

改进QuEChERS-气相色谱-质谱法快速分析测定农用土壤中多环芳烃

建立农用土壤中16种多环芳烃的改进QuEChERS快速提取净化方法及气相色谱-质谱检测方法,并通过对西安市周边农用土壤样品的分析,调查土壤中多环芳烃的污染情况.土壤样品用KOH饱和的甲醇碱化处理后,用丙酮-正已烷(1+1)为提取溶剂,涡旋混匀后超声提取,提取液按改进QuEChERS方法加入无水MgSO4、硅胶及正丙基乙二胺(PSA)进行净化,检测时选用DB -5 MS(30m×0.25 mm×0.25 μm)色谱柱分离,EI电离源及离子监测模式检测,16种多环芳烃的测定低限0.7～3.2μg/kg,加标回收率79.8％ ～ 109.6％,相对标准偏差均低于9.4％.检测的农用土壤样品中均检出有不同程度的多环芳烃残留,约16.7％的土壤样品为轻度污染.     

顶空固相微萃取-气相色谱-质谱法同时测定饮用水源水中24种VOCs

建立了同时测定饮用水源水中24种挥发性有机物(VOCs)的顶空固相微萃取-气相色谱-质谱法.用75 μm CarboxenTM-Polydimethylsiloxane(CAR-PDMS)固相微萃取柱顶空萃取水样中的VOCs,VOCs用气相色谱-质谱联用仪检测,采用内标法定量.对萃取柱涂层、样品盐度、萃取温度和萃取时间等样品前处理条件进行了优化,VOCs的检出限在0.03～0.31 μg/L之间,线性相关系数r＞0.996(二氯甲烷和三氯甲烷除外).对饮用水源水实际水样0.50μg/L和1.00 μg/L两个加标浓度水平的回收率进行了测定,三氯甲烷回收率均值分别为104％和142％,其余VOCs回收率分别为90.0％～120％和88.0％～110％,除二氯甲烷和三氯甲烷外,其余VOCs测定结果的相对标准偏差均小于15.0％(n=6).该方法适用于饮用水源水中挥发性有机物的监测分析.     

有机硅橡胶裂解产物气相色谱-质谱联用分析

以室温硅橡胶和高温硅橡胶产品的边角废料及次品作为实验原料,进行到催化和碱催化裂解,将裂解产物进行气相色谱－质谱（ＧＣ－ＭＳ）联用分析,经过质谱数据检索,确定了两种酸催化产物的组成,高温橡胶的酸催化裂解产物主要是环状化物合;室温橡胶的酸催化一妥产物中有太和链状两类化合物,该实验为硅像胶废料利用提供了依据。碱催化产物太复杂,产物利用存在困难。     

粮谷中11种二硝基苯胺类除草剂残留量的气相色谱-串联质谱法测定

建立了粮谷中11种二硝基苯胺类除草剂残留量的气相色谱-串联质潜(GC-MS/MS)测定方法,样品经乙腈提取、QuEChERS法净化,采用GC-MS/MS在多反应监测模式下进行快速分析,外标法定量.在优化实验条件下,11种二硝基苯胺类除草剂的线性范围均为1.0～20.0μg/L,相关系数大于0.996,方法定量下限为5μ...     

微波萃取气相色谱–质谱法测定发泡塑料中的甲酰胺

建立了测定发泡塑料中甲酰胺含量的气相色谱–质谱法。以乙醇于80℃微波萃取样品,用气相色谱–质谱联用仪SIM模式外标法定量测定发泡塑料中甲酰胺残留量。在优化的实验条件下,甲酰胺的质量浓度在0~10.0μg/m L范围内与色谱峰面积成良好的线性关系,线性相关系数为0.999 8。甲酰胺的检出限为1.0 mg/kg,样品加标回收率为97.5%~102.3%,测定结果的相对标准偏差为0.57%~3.07%(n=6)。该方法样品处理简单、快速,适用于发泡塑料中甲酰胺的日常检测。     

气相色谱-质谱法同时测定水果中9种保鲜剂的残留量

建立了采用气相色谱-质谱(GC-MS)同时测定水果中9种保鲜剂残留量的分析方法。水果样品用正己烷/乙酸乙酯(1/1,v/v)混合提取剂超声提取,经Florisil层析柱净化后用正己烷/乙酸乙酯(1/3,v/v)混合洗脱剂洗脱,以磷酸三苯脂(TPP)为内标物,采用GC-MS的全扫描方式(SCAN)和选择离子监测方式(SIM)对9种保鲜剂进行定性与定量分析。实验结果表明,9种保鲜剂的检出限(LOD)为0.10~2.16μg/kg,在50、100、200μg/kg添加水平下的回收率为75.3%~128%,相对标准偏差为1.57%~11.6%。本分析方法样品前处理简便,净化效果明显,在SIM谱图中分析目标物响应值大、灵敏度高,定量准确可靠,能够满足保鲜剂痕量残留的检测要求。     

Determination of Phenoxy Acid Pesticides in Frog and Fish Tissues by Gas Chromatography-Mass Spectrometry

A gas chromatography-mass spectrometric GC-MS method has been developed for the determination of 2,4-dichlorophenoxyacetic acid (2,4-D) and 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) in frog and fish tissues. After homogenization and sonication of 5 g samples, purification was achieved by a liquid phase extraction procedure using methyl-tert-butyl ether. The extract was reacted for 30 min at 80 °C with 10 % H₂SO₄ in methanol to form the corresponding methyl esters, which were simultaneously extracted with petroleum ether, and analysed by GC-MS in selected ion monitoring mode. Detection limits were 1.0 and 0.5 μg. kg^?1 for 2,4-D and 2,4,5-T respectively in tissue samples and the calibration curves showed good linearity (r ≥ 0.999). Twenty-five frog samples and forty-six fish samples from various regions in Korea were analyzed. 2,4,5-T was detected up to a maximum concentration of 16.2 μg kg^?1 in frogs and fish. The developed method may be valuable for the national monitoring project of endocrine disruptors (EDs) in biota.     

固相萃取-气相色谱-质谱法测定食品中23种邻苯二甲酸酯

建立了同时检测食品中23种邻苯二甲酸酯类化合物的固相萃取-气相色谱-质谱(GC-MS)分析方法。样品经正己烷或乙腈提取、玻璃ProElut PSA固相萃取柱净化,GC-MS选择离子监测模式(SIM)测定。考察了不同种类食品的提取、净化方法。23种邻苯二甲酸酯的线性范围除邻苯二甲酸二异壬酯(DINP)和邻苯二甲酸二异癸酯(DIDP)为0.5～5 mg/L外,其余均为0.05～5 mg/L,相关系数(r)除DIDP外均大于0.99。方法的检出限(信噪比为3)为0.005～0.05 mg/kg,定量限(信噪比为10)为0.02～0.2 mg/kg。在10种食品基质中3个加标水平的平均回收率为77%～112%,相对标准偏差(RSD,n=6)为4.1%～12.5%。该方法稳定、可靠,操作简单,适用于食品中邻苯二甲酸酯类化合物的检测与确证。     

气相色谱-电子轰击离子源质谱法分析卷烟和烟叶中29种农药的残留

开展了卷烟和烟叶中有机氯、有机磷和拟除虫菊酯3类29种农药残留的气相色谱-电子轰击离子源质谱(GC-EI/MS)的分析方法研究。优化与选择了卷烟和烟叶样品的前处理条件,样品经正己烷-丙酮(体积比为1∶1)混合提取剂超声提取、Florisil硅土和中性氧化铝双净化剂固相萃取柱净化、二氯甲烷-正己烷(体积比为95∶5)混合洗脱剂洗脱和浓缩后,以磷酸三苯酯(TPP)为内标物,采用GC-EI/MS的选择离子监测方式(SIM)进行定性和定量分析。当样品的加标水平为20,50,100 μg/kg时,加标回收率为70%～110%,相对标准偏差在2%～8%之间;除了甲氰菊酯、氯菊酯和溴氰菊酯的方法检出限(LOD)分别为1.85,1.74与2.54 μg/kg外,其余的26种农药的LOD均小于0.8 μg/kg;线性范围为5.0～500.0 μg/kg,相关系数都大于等于0.9994。此分析方法已成功地应用于卷烟和烟叶样品中3类29种痕量农药残留的分析     

Determination of acrylamide in starch-based foods by HPLC with pre-column ultraviolet derivatization

A new method is developed for the determination of acrylamide in starch-based foods. The method included the extraction of acrylamide with water, defatting with hexane, derivatization with potassium bromate (KBrO(3)) and potassium bromide (KBr), liquid-liquid extraction with ethyl acetate-hexane (4:1), and concentration. The final analyte (2-bromopropenamide, 2-BPA) is analyzed by high-performance liquid chromatography coupled with diode array detection for quantification and by gas chromatography coupled to mass spectrometry for confirmation. The chromatographic analysis is performed on an ODS-3 C(18) column, and good retention and peak response of acrylamide are achieved under the optimal conditions. The limit of detection and quantitation are estimated to be 15 and 50 μg/kg, respectively. The recoveries of acrylamide from the commercial samples are spiked at levels of 50-1000 μg/kg, and range between 89.6 and 102.0%. These results show that this method should be regarded as a new, low-cost, and robust alternative for conventional investigation of acrylamide.