空气中正硅酸四甲酯(TMOS)检测方案(离子迁移谱仪)

Tetramethyl Orthosilicate (TMOS) detection by Advanced Ion Mobility Spectrometer-AlMSMasa 离子迁移谱检测痕量正硅酸四甲酯(TMOS) The ion mobility spectrometry technique offers advantages like high sensitivity (ppb range)， fast response (ms range)， compact design，operation in atmospheric pressure and ability to separate the isomeric compounds. In this short report we demonstrate the sensitivity and fastresponse of IMS technique at low ppb level. As a case compound was chosen Tetramethyl Orthosilicate TMOS 离子迁移谱技术具有灵敏度高(ppb范围)、响应速度快 (ms范围)、设计紧凑、在亚大气压下工作以及能够分离异构体等优点。在这篇简短的报告中，我们展示了 PAIMS 技术在低 ppb 水平下的灵敏度和快速响应。作为一个案例化合物选择四甲基正硅酸 TMOSThe TMOS Si(OCH3)4 of molar mass 152.25 g/mol， is frequently used in in organic synthesis . The TMOS at low concentrations inhalation causes lung lesions， and at slightly higher concentrations eye contact with the vapor causes blindness. Due to this reasons is monitoring of TMOS inlow concentration required especial in clean industrial hall where it is frequently used. TMOS-Si (OCH3)4分子量为152.25g/mol， 是有机合成中常用的化合物。吸入低浓度 TMOS 会导致肺部损伤，而稍高浓度时，眼睛接.触蒸汽会导致失明。因此，需要对低浓度的TMOS 进行监测，特别是在洁净车间中经常使用。 Fig.1. Tetramethyl Orthosilicate In this short Laboratory Report we demonstrate the ability of lon Mobility Spectrometer operated in sub-atmospheric pressure for continuousmonitoring of TMOS at low ppb level. 在这份简短的实验室报告中，我们展示了大气压下运行的离子迁移谱仪在低 ppb 水平下连续监测 TMOS 的能力。 Experiment The Portable-Advanced Ion Mobility Spectrometer (PAIMS) was used in this experiment. The operating parameters of PAIMS arelisted in Table 1. 实验采用便携式高级离子迁移谱仪(PAIMS)、Masa 空气发生器进行实验。 PAIMS 的工作参数见表 1 工作压力： 600mbar 工作温度： 120℃ 漂移气体： 零级空气 漂移气体流量： 700ml/min 飘逸场强： 570V/cm 进样流量： 60ml/min 极性： 正极 Table 1.PAIMS 工作参数 The TMOS of analytical grade purity (Merck) was used in this experiment. The 1mL syringe of TMOS vapors diluted in ratio 1：20 withatmospheric air was used. The syringe was placed to syringe pump (Cronus) and interfaced via 2m long capillary of 0.15mm i.d. to PAIMSsample inlet. The long capillary with small i.d. was used in order to prevent diffusion. For calculation of concentration was used vapor pressure12 mmHg (PubChem). The PAIMS operate in sub-atmospheric pressure and continuous sample sniffing was set to 60 mL/min. The sample inletsuck the atmospheric air， the vapors from the syringe was diluted to sample inlet flow by syringe pump 本实验采用分析级纯度 TMOS(Merck)。使用 1mL TMOS蒸汽注射器，以1：20 的比例与大气空气稀释。将注射器放置在注射泵(Cronus)上，并通过内径为 0.15mm 的 2m 长毛细管连接至 PAIMS 样品入口。为了防止扩散，采用了内径较小的长毛细管。浓度计算采用蒸汽压 12mmHg (PubChem)。 PAIMS 在亚大气压下运行，连续样品进样设定为60 mL/min。样品入口吸入大气空气，注射器中的蒸汽通过注射泵稀释至样品入口流量 结果和讨论 Figure 2. IMS response on 1.3 ppm of TMOS. Left IMS spectrum measured in reduced mobilitymode， Right 2D map of 30s record time Tlyon.com 图2. IMS 对 1.3 ppm TMOS 的响应。左 IMS 谱在降低移动性模式下测量，右2D图记录时间 30秒 The IMS response on 1.3 ppm of TMOS is show on figure 2. As we can see from this figure there occur to formation of two peaks： TMOS withreduced mobility 1.69 cm2.V-1s-1 and 2TMOS with reduced mobility 1.27 cm2.V-1s-1. We suppose that there is going about formation ofprotonated monomer H+.TMOS (reduced mobility 1.69 cm2.V-1s-1) and proton bound dimer H+.(TMOS)2 (reduced mobility1.27 cm2.V-1s-1).The 2D maps on the right side of figure 2 show perfect stability of IMS response during the scan time 30s. During the experiment also longerscan time was tested (20min) and only small deviation bellow 1% in peak intensity was observed. The Limit Of Detection (LOD) for TMOS was measured directly and was determined 6.5 ppb. Figure 3 shows the IMS response for syringe rate0.5 pL/min what represents 6.5 ppb. 图2显示了1.3ppm TMOS 的 IMS 响应。从这张图中我们可以看到两个峰值的形成：迁移率降低 1.69 cm2.V-1s-1 的 TMOS 和迁移率降低1.27 cm2.V-1s-1的 2TMOS。我们假设有质子化单体 H+.TMOS (还原迁移率1.69cm2.V-1s-1)和质子束缚二聚体 H+ (TMOS)2(还原迁移率 1.27cm2.V-1s-1)的形成。图2右侧的二维图显示，在30秒的扫描时间内， IMS响应完全稳定。在实验期间，还测试了较长的扫描时间(20分钟)，仅观察到峰值强度低于1%的小偏差。 直接测定 TMOS 的检出限(LOD) 为6.5ppb。图3显示了注射速率为 0.5pL/min 的 IMS响应， 即6.5 ppb。 Figure 3. IMS response for 6.5 ppb of TMOS 图 3. TMOS 浓度 6.5ppb下 IMS 响应 The MaSaTECH software allow calculation of peak volume， peak area， averaged peak area along the monitoring time as well like peak intensityand averaged peak intensity along the monitoring time. The PAIMS results in good dynamic range from 6.5ppb to 3.9ppm as we can see from Figure 4. MaSaTECH 软件允许计算沿监测时间的峰值体积、峰值面积、平均峰值面积以及沿监测时间的峰值强度和平均峰值强度。从图4可以看出， PAIMS 的动态范围从 6.5ppb到 3.9ppm。 Calibration table- X Figure 4. TMOS 从 6.5ppb至3.9ppm 范围IMS 响应 MaSaTECH software allow us to use several fitting functions like linear， exponential， logarithmic， logistic and generalized logistic. For TMOS thegeneralized logistic in combination with logistic fitting function seems to be appropriate with R2=0.9951. The volume of peak area against theTMOS concentration was used for formation of calibration table. MaSaTECH 软件允许我们使用一些拟合函数，如线性、指数、对数、logistic 和广义 logistic。对于 TMOS， 广义 logistic 与 logistic 拟合函数相结合， R2=0.9951。用峰面积与 TMOS 浓度的比值来建立校准表 峰面积(Arb.Unit) 浓度 ppb 0.0837 6.5 0.0879 13 0.103 39 0.13 78 0.1643 130 0.198 260 0.361 650 0.593 1300 1.167 3900 0.0837 6.5 Table2 TMOS校准表 Fast Response The main advantage of linear Ion Mobility Spectrometers is related with fast response. The automatic peak derivation and uniquemeasurements in reduced mobility mode allows our instruments fast peak detection and recognition. The online peak derivation giving alsoreal-time information about intensity of target peak. The peak intensity can be used for immediate calculation of concentration for eachchemical. 离子迁移谱仪的主要优点是响应速度快。在低迁移率模式下的自动峰值推导和独特测量允许我们的仪器快速峰值检测和识别。在线峰值推导还提供了有关目标峰强度的实时信息。峰值强度可立即计算每种化学品的浓度。 The ion mobility spectrometry technique offers advantages like high sensitivity (ppb range), fast response (ms range), compact design, operation in atmospheric pressure and ability to separate the isomeric compounds. In this short report we demonstrate the sensitivity and fast response of IMS technique at low ppb level. As a case compound was chosen Tetramethyl Orthosilicate TMOS离子迁移谱技术具有灵敏度高（ppb范围）、响应速度快（ms范围）、设计紧凑、在亚大气压下工作以及能够分离异构体等优点。在这篇简短的报告中，我们展示了PAIMS技术在低ppb水平下的灵敏度和快速响应。作为一个案例化合物选择四甲基正硅酸TMOSThe TMOS Si(OCH3)4 of molar mass 152.25 g/mol, is frequently used in in organic synthesis . The TMOS at low concentrations inhalation causes lung lesions, and at slightly higher concentrations eye contact with the vapor causes blindness. Due to this reasons is monitoring of TMOS in low concentration required especial in clean industrial hall where it is frequently used.TMOS-Si（OCH3）4分子量为152.25g/mol，是有机合成中常用的化合物。吸入低浓度TMOS会导致肺部损伤，而稍高浓度时，眼睛接触蒸汽会导致失明。因此，需要对低浓度的TMOS进行监测，特别是在洁净车间中经常使用。In this short Laboratory Report we demonstrate the ability of Ion Mobility Spectrometer operated in sub-atmospheric pressure for continuous monitoring of TMOS at low ppb level.在这份简短的实验室报告中，我们展示了大气压下运行的离子迁移谱仪在低ppb水平下连续监测TMOS的能力。