微波萃取-气相色谱法测定尿液中的苯丙胺类毒品

建立了人体尿液中甲基苯丙胺(MA)、3,4-亚甲二氧基苯丙胺(MDA)、3,4-亚甲二氧基甲基苯丙胺(MDMA)的微波萃取-气相色谱(GC)测定方法。分别考察了萃取溶剂种类、用量、pH值以及萃取温度、时间等因素对萃取率的影响。实验结果表明,尿液中MA,MDA,MDMA的最佳提取条件为:调节尿样pH为12,以环己烷为萃取溶剂,于40 ℃下微波提取10 min。在此条件下MA,MDA,MDMA的平均回收率分别为92.25%,85.94%和91.50%,相对标准偏差分别为5.5%,5.5%和6.1% (n=5),提取液经气相色谱-氢火焰离子化检测器(GC-FID)检测,3种药物与基体得到了很好的分离,对尿液中MA,MDA,MDMA的最低检测限分别为10,20和20 ng/mL。该方法未对药物进行衍生化,是一种快速、准确、灵敏度高的同时测定尿液中MA,MDA,MDMA的方法。     

超声液相萃取-GC/MS-SIM法定量检测唾液中苯丙胺类毒品

建立了一种人体唾液中苯丙胺(AM)、甲基苯丙胺(MAM)、 3, 4-亚甲二氧基苯丙胺(MDA)、 3, 4-亚甲二氧基甲基苯丙胺(MDMA)毒品的超声波液液萃取-气相色谱/质谱-选择离子检测方法. 对萃取溶剂、萃取时间等参数进行了考查, 确定了乙酸乙酯为萃取溶剂, 在超声波下液液萃取2 min. 用该溶剂对添加毒品的唾液进行提取, 采用气相色谱/质谱-选择离子检测法(GC/MS-SIM)检测, 获得了良好线性, 相对标准偏差在15%内, 准确性均在80%～115%之间, 最小检测限可达0.05 μg/mL. 该方法未对毒品进行衍生化处理, 可用于缴获毒品及嫌疑吸毒者人体生物检材中苯丙胺类毒品的分析.     

微波辅助萃取-气相色谱质谱法检测生物体内的多溴联苯醚

建立了微波辅助萃取-气相色谱质谱法测定生物样品中的多溴联苯醚(PBDEs)的方法,优化了萃取剂的种类、萃取剂用量、萃取时间等微波萃取条件和GC-MS仪器分析条件。正己烷-丙酮混合溶剂提取后,经实验室自制的多层硅胶柱分离纯化,用气相色谱-质谱进行测定,该方法基质加标回收率在60%～77%之间,相对标准偏差在11%～18%之间,方法的检测限为0.03～0.20ng/g,适用于生物样品中PBDEs的测定。     

微波萃取-气相色谱法测定血液中的可卡因及其代谢物爱冈宁甲基酯

建立了血液中可卡因(cocaine, COC)及其代谢物爱冈宁甲基酯(ecgonine methyl ester, EME)的气相色谱-质谱(CG-MS)和气相色谱-氢火焰离子化检测(GC-FID)方法。该方法采用微波萃取提取血液中的COC和EME,优化并确定了最佳提取条件: 以氯仿-异丙醇(体积比为9:1)混合溶液为提取溶剂,用0.05 mol/L Na2CO3-NaHCO3缓冲溶液调节样品溶液的pH至10.0,在40 ℃下微波萃取6 min;采用GC-MS对萃取液中的COC和EME进行定性,采用GC-FID进行定量检测。COC和EME的平均回收率分别为79.91%～99.85%,相对标准偏差(RSD)均小于3.10%,检出限(S/N=3)分别为60 mg/L和40 mg/L。该方法无需衍生化,快速、准确、灵敏,可同时检测血液中的COC和EME。     

唾液中苯丙胺类毒品的液相小体积萃取GC/MS-SIM检测

建立了一种便捷的唾液中4种毒品(苯丙胺(AM)、甲基苯丙胺(MAM)、3,4-(亚甲二氧基)苯丙胺(MDA)、3,4(亚甲二氧基)-甲基苯丙胺(MDMA))的液相小体积超声提取-气相色谱/质谱-选择离子检测分析方法并考察了小体积萃取溶剂和体积对萃取效果的影响.该方法用100μL环己烷对唾液中的毒品进行提取,直接抽取提取液用气相色谱/质谱-选择离子(GC/MS-SIM)检测,获得良好线性,相对标准偏差在15%内,准确性均在80%～120%之间,最小检测限可达0.1μg/mL.该方法灵敏、简便、快速,可用于缴获毒品及嫌疑吸毒者人体生物检材中苯丙胺类毒品的分析.     

中空纤维膜液相微萃取-气相色谱/质谱法检测尿液中的苯丙胺类兴奋剂

建立了尿液中痕量苯丙胺类毒品的中空纤维膜液相微萃取-气相色谱/质谱检测方法。采用中空纤维膜液相微萃取技术萃取尿液中4种苯丙胺类毒品,研究萃取剂类型、体积、溶液pH、萃取时间和温度等对萃取效果的影响。尿液中4种苯丙胺类毒品的最佳萃取条件为:样品溶液pH 13,甲苯为萃取剂,搅拌速度500 r/min,30℃条件下萃取15 min;此条件下苯丙胺(AM)、甲基苯丙胺(MAM)、3,4-亚甲二氧基苯丙胺(MDA)、3,4-亚甲二氧基甲基苯丙胺(MDMA)的检出限(S/N=3)分别为1.0,0.75,1.0,0.64 ng/mL,相对标准偏差分别为6.62%,3.98%,4.57%,2.35%,富集倍数分别为155,170,132,218倍。本方法可用于尿液中痕量苯丙胺类毒品的分析测定。     

非极性溶剂微波萃取-气相色谱-质谱法测定白豆蔻中挥发油成分

提出了非极性溶剂微波萃取-气相色谱-质谱法测定白豆蔻中的挥发油成分的方法。优化的试验条件如下:①微波吸收介质为0.35g石墨粉;②提取溶剂为正己烷;③样品质量与溶剂容积之比为2g比25mL;④提取时间为30min。在气相色谱分离中用DB-5石英毛细管柱为固定相,在质谱分析中采用全扫描检测模式。以α-甲基苯甲醇丙酸酯为内标物。方法用于白豆蔻样品的分析,共鉴定出60种挥发性化学成分,主要化合物为桉油精(70.34%)、β-蒎烯(6.81%)、α-松油醇(3.36%)和α-蒎烯(2.54%)等。     

环境和生物样品中有机氯农药残留检测研究进展

综述了环境和生物样品中有机氯农药残留检测中样品的前处理方法(包括溶剂提取、溶剂提取和层析柱分离法、微波萃取、凝胶渗透色谱净化法、固相萃取法等)和测定方法(包括气相色谱法、气相色谱-质谱法等)的研究进展。     

气相色谱-质谱法检测白酒和黄酒中18种邻苯二甲酸酯类增塑剂

建立了白酒和黄酒中增塑剂的液液萃取法提取,气相色谱-质谱法检测技术,内标法定量。考察了基质效应,萃取方法等主要条件,并最终确定正己烷为提取溶剂的液液萃取技术,并且提取过程中加入NaCl和H2O。在优化的条件下,18种增塑剂均具有较好的线性相关性,线性相关系数均大于0.9978,白酒和黄酒的添加回收率、相对标准偏差分别为75.7%~97.5%、2.3%~6.7%和74.8%~96.0%、1.9%~7.1%;检出限均小于0.05 mg/kg。方法可为酒中增塑剂检测的标准方法的建立提供参考。     

气相色谱法测定尿液中可卡因及其代谢物爱冈宁甲基酯

建立了尿样中可卡因（COC）及其代谢物爱冈宁甲基酯（EME）的气相色谱检测方法。 采用液液萃取法提取尿样中可卡因和爱冈宁甲基酯,考察了萃取剂种类和用量、试样pH值以及萃取时间等因素对提取效果的影响。 结果表明,尿样中COC和EME的最佳液液萃取条件是：以V(氯仿)∶V(异丙醇)=9∶1为提取溶剂,调节样品溶液pH=9.5,在40 ℃ 水浴振荡提取6 min。 COC和EME日内精密度分别为1.73%和1.44%,日间精密度分别为2.57%和2.89%,最低检出限（LOD）为0.040 mg/L。 此法无需衍生化、快速、准确、灵敏度高,可同时检测尿样中COC和EME的含量。     

液相微萃取/离子色谱测定牛奶中的氨

以水为微滴萃取溶剂,采用顶空液相微萃取/离子色谱检测了牛奶中的氨.优化了顶空液相微萃取的实验条件:pH=12,萃取温度为35 ℃,萃取时间为15 min,搅拌速率为800 r/min,萃取溶剂体积为5 μL.测定氨的线性范围为10 ～300 μg·L-1(R2=0.998),检出限达1.8 μg·L-1,回收率为92% ～105%.     

微波辅助提取-固相膜萃取测定水体沉积物中的甲基汞

利用微波辅助提取-固相膜萃取前处理技术分离富集水体沉积物中的甲基汞,固相膜萃取的前处理方法能够集富集和净化为一体,有效地去除基质的影响。方法的关键在于样品的萃取过程,萃取过程中既要保证样品中甲基汞的原来形态不被破坏和转化,又要保证其从样品中被充分萃取以达到稳定可靠的回收效果。通过微波辅助提取技术将水体沉积物中的甲基汞提取到溶液后,提取液通过0.01%的二乙基二硫代氨基甲酸钠改性后的C18固相萃取膜,选择性地将提取液中的甲基汞分离富集的同时净化。洗脱液再经过原子荧光光谱仪进行测定。实验条件考察了流动相、微波提取条件以及固相膜萃取条件对甲基汞的影响。在最优的实验条件下,对甲基汞的稳定性进行了研究,实验结果表明在4 ℃以及-15 ℃条件下贮存,甲基汞降解不显著。同时对沉积物实际样品和加标样品进行了分析,所得结果沉积物中甲基汞检出限为0.20 μg/kg,沉积物实际样品的加标回收率和相对标准偏差分别在71.3%～87.6%和2.00%~6.36%之间,实验结果令人满意。该方法萃取速度快、消耗溶剂少、萃取效率高,可以同时处理多个样品,节约能耗,绿色环保,符合现代监测分析的发展趋势,适用于分析测定水体沉积物中的甲基汞。     

Determination of vitamin A in blood serum based on solid‐phase extraction using cetyltrimethyl ammonium bromide‐modified attapulgite

Cetyltrimethyl ammonium bromide‐modified attapulgite was prepared and utilized as a novel sorbent in a simple solid‐phase extraction method for the determination of vitamin A in blood serum. Several factors affecting extraction efficiency were systematically optimized, including the sampling solvent and its volume, as well as the elution solvent and its volume. Under the optimal solid‐phase extraction conditions, the adsorption capacity of vitamin A was as high as 28 mg/g according to the Langmuir isotherm model. Based on the developed solid‐phase extraction method, the level of vitamin A in 200 µL blood serum sample could be accurately determined by high‐performance liquid chromatography. The recoveries of vitamin A spiked in 10% v/v methanol aqueous solutions were in the range of 86.9–92.8%, with the relative standard deviations not more than 8.1%. The method was applied to the determination of vitamin A in serum samples from 20 pregnant women. Compared with the previously reported solid‐phase extraction methods for determination of vitamin A in serum, our developed cetyltrimethyl ammonium bromide‐modified attapulgite‐based solid‐phase extraction method used lower serum volume, omitted extra steps (i.e. evaporation and re‐dissolution), and eliminated internal standard. The results were promising for it to be used in routine monitoring during pregnancy.     

MAE–GC Determination of Methamphetamine, 3,4-Methylenedioxyamphetamine and 3,4-Methylenedioxymethamphetamine in Human Urine

Methamphetamine (MA), 3,4-methylenedioxyamphetamine (MDA) and 3,4-methylenedioxymethamphetamine (MDMA) were extracted from human urine by using microwave-assisted extraction (MAE) followed by gas chromatography analysis with flame ionization detection. In order to improve the extraction efficiency, experimental parameters on the extraction, including extraction solvent and its volume, pH value of sample, extraction time and temperature were investigated. Under the optimal conditions, the average recoveries of MA, MDA and MDMA were 92.25, 85.94 and 91.50%, respectively. And the intra-day and inter-day relative standard deviations were not greater than 6.9%. The results indicate that the developed method is rapid, accurate and sensitive, and can be used for the simultaneous determination of MA, MDA and MDMA in urine for forensic application.     

Comparison of microwave-assisted extraction of triazines from soils using water and organic solvents as the extractants

Microwave-assisted extraction (MAE) for the separation of atrazine, simazine and prometryne from synthetic soil samples, using water and some organic solvents as the extractants, was studied in detail. The effects of the soil matrix, the soil moisture and the pH of the aqueous extraction system on the MAE efficiency were also studied. It was found that the three triazines could be efficiently extracted under the conditions of 100% magnetron power output (600 W), the first grade of pressure (from 0.1 MPa to 0.5 MPa), 30 ml solvent and 4 min microwave heating with water or organic solvents, except for prometryne with dichloromethane solvent for 1-4 g sandy loam sample. This interesting result was explained by triazines' solubility in water, their sorption properties in soils and the ability of the solvent to absorb microwave energy. Finally, evaluation of the extraction efficiency, as well as the treatment and determination of MAE extracts, suggested that water, as a cheap, safe and environmentally friendly solvent, can be a good alternative to organic solvents, used as the extractants for MAE of triazines from soils.     

微波辅助-旋转回流提取仪的组装及其在叶下珠有机酸提取中的应用

组装了一种新型的微波辅助旋转回流装置,该装置的基本原理与微波辅助溶剂萃取的原理相同,但采用了旋转的技术以加速提取.应用该装置以正交实验筛选优化叶下珠中有机酸的提取工艺,并利用毛细管电泳技术分离测定了提取液中有机酸的含量以评价提取效果.最佳提取工艺:乙醚为溶剂,微波功率800 W,提取时间4 min,溶剂用量300 mL.在该提取条件下,平行5次提取叶下珠中丁二酸、原儿茶酸、没食子酸、咖啡酸、阿魏酸的平均含量分别为42.2、103.5、436.2、123.8、67.4 μg/g,相对标准偏差为0.87% ～3.7%,加标回收率为94% ～104%.将该法与常规的微波辅助提取法及回流提取法进行比较,结果表明,微波辅助旋转回流提取法提取效率明显优于其它2种方法.     

Development of novel thin-film solid-phase microextraction materials based on deep eutectic solvents for preconcentration of trace amounts of parabens in surface waters

A green and sensitive thin-film solid-phase microextraction method based on deep eutectic solvent was developed that enables simultaneous isolation, preconcentration, and determination of parabens in surface waters. Six new deep eutectic solvents were synthesized and used directly to prepare thin-film coatings on a stainless steel mesh support. Among the compounds obtained, the highest efficiency in the extraction of parabens was found for a material consisting of trihexyltetradecylphosphonium chloride and n-docosanol in a molar ratio of 1:2. For the proposed method, parameters affecting the extraction efficiency of parabens, such as the coating material, the desorption solvent, the volume of the sample, the pH of the sample, the extraction and desorption time, and the salting-out effect, were optimized. Under optimal conditions, the proposed method allowed us to achieve good precision between 3.6 and 6.5% and recovery ranging from 68.1 to 91.4%. The limits of detection range from 0.018 to 0.055 ng/mL.     

野菊花中蒙花苷的提取及其含量的测定

以乙醇为溶剂,采用溶剂回流提取方法结合微波、超声波辅助提取野菊花中的蒙花苷,用HPLC法测定。采用正交试验法研究了野菊花中蒙花苷提取和HPLC实验条件,并比较了采用不同的微波和超声波辅助提取方式对蒙花苷提取结果的影响。结果表明,溶剂回流提取最佳条件为:提取温度80℃,回流时间2.0 h,溶剂用量40 mL。应用于安徽等产地野菊花中蒙花苷的提取分析,结果显示,广东和广西产地药材含量明显更高;在相同的实验条件下采用微波辅助提取可使蒙花苷达到较高的提取率,特别是采用微波辐射药材后再进行溶剂回流提取,提取时间可缩短一半。