Differential mobility spectrometry of chlorocarbons with a micro-fabricated drift tube
Differential mobility spectrometry of chlorocarbons with a micro-fabricated drift tube
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DOI：
10.1039/b316326a
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发表时间：
2004-01-01
期刊：
影响因子：
4.2
通讯作者：
Miller, RA
中科院分区：
文献类型：
--
作者：
Eiceman, GA;Krylov, EV;Miller, RA
通过气相化学在环境压力下在空气中电离的氯代烃和所得的离子，其特征在于使用微制造的漂移管与差分迁移率光谱（DMS）。在配备有3 mCi Ni-63离子源的单个漂移管中，在50 ℃和具有1 ppm水分的空气漂移气体中同时表征正和负产物离子。对大多数氯碳化合物的补偿电压进行扫描，产生了以Cl-为唯一产物离子的微分迁移率谱，少数氯碳化合物产生了加合离子M。Cl-.气相色谱-DMS测量的检测限类似于20-80 pg。氯代烃在空气中也通过化学电离产生正离子，微分迁移率谱显示出具有每种物质特征补偿电压的峰。确定了每种物质的正离子和负离子的迁移率的场依赖性，并确认了每种离子的特征行为。使用带有膜入口的DMS分析仪连续监测来自膨润土柱或合成二氧化硅珠的流出物，以确定各个氯代烃的穿透体积。这些研究结果表明，DMS监测地下环境的潜力，无论是在现场或可能在原地。
Chlorocarbons were ionized through gas phase chemistry at ambient pressure in air and resultant ions were characterized using a micro-fabricated drift tube with differential mobility spectrometry (DMS). Positive and negative product ions were characterized simultaneously in a single drift tube equipped with a 3 mCi Ni-63 ion source at 50 degreesC and drift gas of air with 1 ppm moisture. Scans of compensation voltage for most chlorocarbons produced differential mobility spectra with Cl- as the sole product ion and a few chlorocarbons produced adduct ions, M. Cl-. Detection limits were similar to 20-80 pg for gas chromatography-DMS measurements. Chlorocarbons also yielded positive ions through chemical ionization in air and differential mobility spectra showed peaks with characteristic compensation voltages for each substance. Field dependence of mobility was determined for positive and negative ions of each substance and confirmed characteristic behavior for each ion. A DMS analyzer with a membrane inlet was used to continuously monitor effluent from columns of bentonite or synthetic silica beads to determine breakthrough volumes of individual chlorocarbons. These findings suggest a potential of DMS for monitoring subsurface environments either on site or perhaps in situ.