凝胶渗透色谱净化-气相色谱-质谱法同时测定金银花中33种农药残留组分

建立了凝胶渗透色谱(GPC)净化、气相色谱-质谱(GC-MS)同时测定金银花中33种有机氯、有机磷和拟除虫菊酯农药残留的方法.样品中的待测农药组分经乙酸乙酯-环己烷混合溶剂(1∶ 1, V/V)提取、GPC净化去除色素等杂质,GC-MS采用全扫描/选择离子监测模式(Scan/SIM)采集数据后进行定性/定量分析.方法的相对标准偏差(RSD)≤16.70 %(6.9～84.6 ng/g,n=5);5种不同加标浓度下,待测农药的标准加入回收率在57.4%(甲胺磷)～109.9%(马拉硫磷)之间;各农药组分的定性检出限(3σ)为0.10～10.5 ng/g,定量检出限(10 σ)为0.33～20.0 ng/g.     

在线凝胶渗透色谱串联气相色谱-质谱快速测定粮谷及油料作物中29种农药残留

采用在线凝胶渗透色谱串联气相色谱-质谱(GPC/GC-MS),在选择离子模式(SIM)下建立了粮谷和油料作物中29种农药残留的分析方法。样品用乙腈溶液提取,经无水Na2SO4和N-丙基乙二胺(PSA)吸附剂净化后,直接进行GPC/GC-MS分析,外标法定量。29种农药在0.25～600μg.L-1范围内具有较好的线性关系,相关系数均大于0.99。29种农药在3个加标水平(MRL、2MRL、4MRL)下的回收率为65%～148%;其中狄氏剂、对硫磷和甲胺磷等11种农药的LOQ(S/N≥10)为2.0～6.0μg·kg-1,敌敌畏、乐果和六六六等18种农药的LOQ均小于1.0μg·kg-1。该方法样品前处理简单、分析时间短、灵敏、可靠,适用于粮谷和油料作物中多种农药残留的检测。     

气相色谱-电子捕获检测法和气相色谱-质谱法同时测定鱼体内19种有机氯农药

建立了气相色谱-电子捕获检测(GC-ECD)法同时测定,及气相色谱-离子阱-多级质谱(GC-IT-MS/MS)法定量确证鱼体中19种有机氯农药(OCPs)残留的检测方法。目标物采用浸渍-振荡法提取,固相萃取(SPE)(脂肪含量≤1.0%)和凝胶色谱(GPC)净化,浓缩,定容后上机测定。草鱼肌肉空白组织中目标化合物的添加浓度为2.0、5.0μg/kg时,GC-ECD法与GC-IT-MS/MS法的回收率分别为72.8%～96%和78.8%～106%,相对标准偏差分别为2.1%～14.9%和4.8%～11%。定量限(S/N=10)分别为0.07～1.44μg/kg和0.10～4.27μg/kg。本方法已成功应用于长江圆口铜鱼体中多种OCPs残留的同时测定。     

凝胶渗透色谱净化-超高效液相色谱-串联质谱法测定皮革制品中7种尼泊金酯类防腐剂

利用超高效液相色谱-串联质谱(UPLC-MS/MS)结合凝胶渗透色谱(GPC)技术,建立了一种快速分离和测定皮革制品中7种尼泊金酯类防腐剂的分析方法。样品经超声提取、浓缩、GPC净化,甲醇-水溶液(1:1, v/v)溶解,采用Acquity UPLCBEH C18柱(50 mm×2.1 mm, 1.7 μm)分离,以甲醇和水为流动相,梯度洗脱,电喷雾负离子模式电离,采用多反应监测模式检测和外标法定量。该方法在0.1～1.0 mg/L范围内线性关系良好(r＞0.99);在添加量为0.5～3.0 mg/kg时,平均回收率为(79.44±5.67)%～(98.07±9.50)%,相对标准偏差(RSD)为4.24%～14.00%;方法的检出限(LOD)为4～12 μg/kg,定量限(LOQ)为13.2～39.6 μg/kg。该方法操作简便、快捷、灵敏、准确,适合皮革中多种尼泊金酯类防腐剂的确证和定量测定。     

凝胶渗透色谱-固相萃取净化测定茶叶中16种菊酯残留量

建立了以凝胶渗透色谱(GPC)和固相萃取(SPE)净化,气相色谱-质谱(GC-MS)负化学源(NCI)技术测定茶叶中七氟菊酯、 四氟菊酯、丙烯菊酯、联苯菊酯、胺菊酯、甲氰菊酯、氯氟氰菊酯、氟丙菊酯、苯醚氰菊酯、氟氯氰菊酯、氯氰菊酯、氟氰戊菊酯、氰戊菊酯、 氟胺氰菊酯、溴氰菊酯、氯菊酯等16种菊酯残留量的方法.样品经V(丙酮)∶V(乙酸乙酯)∶V(正己烷)＝1∶2∶1提取,经GPC去除大分子的色素和类脂杂质,弗罗里硅土 SPE柱进一步净化,以毒死蜱同位素D-10作内标,内标法定量.方法的回收率67.2%～108%之间.变异系数小于18%.16种菊酯方法定量限在0.0125～0.025 mg/kg之间.     

凝胶渗透色谱柱去脂-气相色谱-质谱法测定人血清中新型卤系阻燃剂

建立了凝胶渗透色谱(GPC)去脂,气相色谱-负化学电离源-质谱(GC-NCI-MS)法测定人血清中2,2’,4,4’,5,5’-六溴联苯(BB-153)、1,2-二(2,4,6-三溴苯氧基)乙烷(BTBPE)和德克隆(Dechlorane plus,DP,包括syn-DP和anti-DP)的方法。人血清样本加入内标13C12BB-153和13C10syn-DP,经蛋白质变性、脂肪提取、GPC去脂、酸性硅胶柱净化后,利用气相色谱-负化学电离源-质谱法测定样品中BB-153,BTBPE,syn-DP和anti-DP,监测离子分别为m/z 627.5,629.5,m/z 79,81以及m/z 652,654。结果表明,13 C12 BB-153和13 C10syn-DP的血清加标回收率分别为91.5%±8.9%和92.3%±8.1%,检出限为0.6～1.2 ng/g脂肪。应用本方法对人血样品进行测定,BB-153和BTBPE在所有样本中均未检出,syn-DP和anti-DP的浓度范围分别是0.7～9.2 ng/g脂肪和0.6～2.0 ng/g脂肪。     

凝胶渗透色谱净化-高效液相色谱法测定油脂食品中的邻苯二甲酸酯类增塑剂

建立了油脂食品(方便面、油炸糕点、沙琪玛、食用油等)中5种主要邻苯二甲酸酯类增塑剂的凝胶渗透色谱（GPC）净化-高效液相色谱(HPLC)分析方法。食品样品用石油醚超声提取,经GPC净化后,采用反相HPLC进行分析。所用的分离柱为Labtech C18(250 mm×4.6 mm, 5 μm),以乙腈和水为流动相,梯度洗脱。方法的相关系数皆在0.997以上,目标物的检出限(信噪比为3计)为3.25～13.4 μg/L。在50 mg/L添加水平时,目标物的加标回收率为70.4%～113.6%,相对标准偏差为0.3%～5.8%(n=3)。该方法简便、快捷、实用,可用于油脂食品中邻苯二甲酸酯类增塑剂的分析测定。     

凝胶渗透色谱净化/气相色谱-负化学源质谱法测定肉及肉制品中氯化松节油残留

采用凝胶渗透色谱(GPC)净化技术,建立了猪肉、牛肉、羊肉、鸡肉4种肉类及腊肉和肉松2种肉制品中氯化松节油残留量的气相色谱-负化学源质谱(GC-NCI/MS)测定方法。样品经正己烷涡旋振荡提取,乙酸乙酯-环己烷(1∶1)为流动相进行凝胶渗透色谱净化,采用选择离子监测模式(SIM)测定,外标法定量。氯化松节油在0.01～2.0 mg/L质量浓度范围内呈良好线性,相关系数(r)为0.999 7。方法定量下限为10μg/kg。对上述6种基质,分别在10.0～50.0μg/kg之间进行4个不同水平的加标回收实验,加标回收率为80%～98%,相对标准偏差(RSD,n=8)为2.1%～8.7%。该方法适用于多种肉类及肉制品中氯化松节油残留量的确证及定量检测。     

农产品中甲草胺残留量的气相色谱-质谱检测

建立了玉米、花生、菠菜、柑橘4种不同类型农产品中甲草胺残留量的检测方法。样品先用丙酮-水(体积比为8∶2)提取,经二氯甲烷液-液分配,再用凝胶色谱(GPC)和固相萃取(SPE)去除色素和提取待测物,最后采用气相色谱-质谱测定,外标法定量。甲草胺的添加水平为0.010～0.200 mg/kg时,平均回收率为86.0%～98.2%;相对标准偏差为5.1%～6.7%;方法的测定低限为0.010 mg/kg。     

快速溶剂萃取-气相色谱-三重四极杆质谱法测定沉积物中的酞酸酯

建立了快速溶剂萃取(ASE)-气相色谱-三重四极杆质谱(GC-MS/MS)测定沉积物中酞酸酯的方法。样品用二氯甲烷-丙酮(体积比为1:1)混合溶剂在100 ℃、103.4 MPa (1500 psi)条件下经快速溶剂萃取、以5 mL/min的速率经凝胶渗透色谱(GPC)净化去除大分子干扰物后,采用GC-MS/MS分析测定。采用内标法定量,17种酞酸酯的检出限为0.05～0.40 μg/kg;回收率为50.5%～107.9%,相对标准偏差为3.5%～13.9%。采用替代物基体加入法对方法的性能进行了验证,3种替代物的回收率为65.3%～95.8%。该方法快速、灵敏度高,能同时准确定性定量测定17种酞酸酯。     

On-line multidimensional chromatography using packed capillary liquid chromatography and capillary gas chromatography

The introduction of selected fractions from a liquid chromatograph into a gas chromatograph has been described; however, analyses were performed by off-line experiments requiring collection and reinjection of the separate fractions or by on-line procedures where disadvantageously, only a fraction of the separated peak or a well resolved component in a mixture could be introduced into a gas chromatograph. This disadvantage is overcome by the apparatus and method described in this paper, which utilizes a multidimensional chromatography system employing a high efficiency, packed capillary LC column coupled on-line to a capillary gas chromatograph. The liquid chromatograph (so designed) can act as a highly efficient clean-up or chemical class fractionation step prior to introduction into the gas chromatograph, significantly reducing sample preparation times in many applications. Thus minor components in a complex matrix can be determined without prior sample clean-up, an example of which is the determination of polychlorinated biphenyls in a complex hydrocarbon matrix.     

On the chromatography mechanism of reversed-phase liquid chromatography

Summary An equation is derived which can describe how the retention of solutes is influenced by the composition of the mobile phase in reversed-phase liquid chromatography, the retention of solutes in alkyl bonded stationary phase regarded as the complexation between solute molecule and the active sites on the surface of the stationary phase. When the stationary phase is not fully saturated by the organic modifier, the activity of the active sites, the activity coefficient of the adsorbed solute as well as the activity coefficient of the solute in the mobile phase depend on the composition of the mobile phase. However, when the stationary phase is fully saturated, the composition of the mobile phase mainly influences the activity coefficient of the solute in the mobile phase. In addition, the selectivity of retention is discussed in terms of the derived equation.     

Circulation chromatography

The main peculiarities and difficulties in the implementation of circulation chromatography are considered. The most impressive results obtained with the use of circulation liquid chromatography for the separation of isotopically substituted and isomeric organic compounds are given. The possibility of the preparative separation of the optical isomers of amino acid derivatives was demonstrated for the first time; thus, a new technique for the separation of optical isomers was developed. The capabilities of the circulation versions of gas-liquid and gas-adsorption chromatography are considered in detail. The possibility of the ultrafine separation of isotopically substituted compounds that differ by only one isotope atom, such as benzene and monodeuterobenzene, was demonstrated.     

Correlation chromatography

In correlation chromatography the usual chromatographic procedure is modified, utilizing the capabilities of microcomputers. The most striking property is the semicontinuous character of the method, leading to a very efficient use of the column and a rapid decrease in the detection limit in a relatively short time.     

Reversed-phase chromatography

HPLC (high-performance liquid chromatography) is an analytical method of great versatility and sensitivity. The use of silica-bonded non-polar stationary phases in place of the traditional polar stationary phases has resulted in the technique of reversed-phase chromatography. This has proved a most useful analytical tool, particularly for the analysis of biological samples. Furthermore the technique has great potential as a means of measuring a number of physicochemical properties.