【第一段】Direct Sample Introduction. The direct measurement of carbon isotope ratio in gases can be done by connecting the sample gas cylinder to the ICP torch using PTFE tubing and a one-flow restrictor, which regulates the flow without the need for a mass flow controller that might induce isotopic fractionation (58). 封存有含碳气体的样品柱，通过聚四氟乙烯导气管和单向阀，与 ICP炬管尾端相连，可实现碳同位素直接测定【译者按：应该是用MC-ICP-MS测定碳同位素】。之所以使用单向阀控制气流量，是因为数控气体流量计可能会产生同位素分馏【译者按：数控气体流量计进出口存在压差，轻重核素的动力学扩差差异可能产生同位素分馏】。
A new inexpensive gas converter apparatus was developed for the real time analysis of airborne particulate matter (APM), which is important to enable the study of APM kinetic behavior in ambient air (59). The apparatus consists of two concentric tubes: a porous silica tube in which the air sample flows, which is in a borosilicate glass tube in which a counterflow of Ar is introduced. Because of the difference in partial pressures in the two tubes, the gas molecules in air are exchanged with Ar, thereby allowing APM to be carried to the plasma with Ar (59). 一种新颖的、便宜的气体转换器被用于实时分析大气颗粒物，该设备的引入对于大气颗粒物动力学研究十分重要。它由两个同心管构成：最中心的是渗透硅管，空气在内流动；最外层的是硼硅酸盐玻璃管，Ar反方向流动。由于两根管子存在压差，中心管内的空气分子被外层管的Ar置换，于是在中心管内，Ar承载着大气颗粒物进入等离子炬焰。
To increase the gas exchange efficiency, three gas converters were used in parallel to allow 650 mL/min air to be introduced and exchanged using 7 L/min Ar sweep gas, with APM of all sizes being directly introduced into the ICP torch injector (59). This however translated into a noisy signal, with many spikes, indicative of a variety of coarse particles reaching the plasma. If a particle size selector were also used at the inlet of the gas converter, kinetic studies related to specific size would become possible, although quantification is problematic, as standards with known elemental concentrations, chemical composition, and particle size distributions are required. 三套气体转换器被平行放置，使得650ml/min的空气与7L/min的Ar能高效置换，各种粒径的大气颗粒物被送入炬管内的中心喷射管。粗、细颗粒气溶胶混杂进入等离子体，这会带来噪声信号。可以在气体转换器入口加装一个粒径过滤器，这样就能针对特定粒径的气溶胶开展大气颗粒物动力学研究。但这样一来，定量研究就存在诸多问题，还需知道内标元素浓度、化学组成、粒径分布等细节。
【第二段】Nebulization. The sample throughput can be doubled with an Elemental Scientific FAST sample introduction system (Figure 3), which uses a diaphragm pump to instantaneously fill a sample loop, the content of which is then injected into an acidic carrier stream (60). The latter, which is pumped by a peristaltic pump, is merged with internal standard solution before reaching a low flow, PFA-ST microconcentric nebulizer that is in-serted in a Peltier-cooled, glass cyclonic spray chamber (60). 利用Elemental Scientific公司(ICPMS">http://www.[url=https://insevent.instrument.com.cn/t/yp]ICPMS.com) 的FAST进样系统，单位时间内测试的样品件数翻倍，即效率翻倍。20ml/min的待测溶液经过隔膜泵，溶剂被当做废液排走，溶质与0.4ml/min的酸液先混合，然后与0.1ml/min内标溶液（可能含Sc Ge Y Rh In Re Tl Bi）混合——吸取酸液与内标溶液，是靠蠕动泵提供动力。最终，这些混合液依次进入四氟乙烯-过氟烷氧基乙烯聚合物材质(Tetrafluoroethylene Perfluoroalkoxyethylene copolymer=PFA)的微同心雾化器、配有珀耳帖冷却系统、石英玻璃材质的气旋式雾化室。
While the injection volume is large enough to result in a steady-state signal, the discrete injections effectively minimize salt build up on the cones. Furthermore, memory effects and washout times are minimized because the sample solution is only in contact with Teflon (i.e., never flows through peristaltic pump tubing) (60), unlike with conventional FI where a peristaltic pump is used to load the sample into the sample loop. Hence, compared to conventional FI combined with a pneumatic cross-flow nebulizer and Scott double-pass spray chamber, better precision and accuracy are achieved, with lower detection limits and reduced sample consumption (61). One exception is Hg for which significant carryover resulted because the FAST sample loop is not really rinsed (i.e., introduction of the next sample rinses the loop) (60). Nonetheless, the high throughput afforded by the FAST system makes it popular with ICPMS vendors, which often use it during demonstrations or while analyzing samples for potential new customers. 当进样体积很大时，虽然能产生平稳的信号，但可能在锥孔上产生较严重的盐沉积，而不连续进样能有效缓解锥孔盐沉积。传统流动注射进样时，要靠蠕动泵承载待测溶液进入sample loop，然后使用正交/错流型雾化器、斯科特型双筒式雾化室。对于FAST进样系统而言，待测溶液仅接触聚四氟乙烯材质的器件，待测溶液消耗较少，记忆效应和清洗时间都大幅降低，准确度与精密度更好，测定限更低——但汞是个例外。通常直接用下一个样品润洗sample loop，而不是用清洗液（例如稀硝酸）认真清洗后再测下一个样品，因此汞的测试效果并不理想。由于FAST进样系统的高效率，ICP-MS商家很赞赏它，经常在新客户面前展示FAST并做现场分析。
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