Karanassion Vassili
Department of Chemistry, University of Waterloo, Waterloo, Ontario, Canada N2L 3G1.
Guang Pu Xue Yu Guang Pu Fen Xi. 2003 Feb;23(1):104-14.
An inductively coupled plasma (ICP) spectrometer equipped with pneumatic nebulization sample introduction requires mL volumes of sample. For direct elemental analysis of small amounts of solids, an ICP equipped either with a direct sample insertion (DSI) or with an electro-thermal vaporization (ETV) sample introduction system would typically require mg amounts of sample. In my laboratories, we have been developing and characterizing a new sample introduction system we call in-torch vaporization (ITV). The ITV sample introduction system improved significantly the detection limits of ICP spectrometry (both atomic emission and mass spectrometry), thus enabling determinations for micro- and sub-micro size liquid or solid samples. In some cases, even microscopic, nano-size samples were successfully analyzed. In the first part of this paper, development of ITV-ICP for both Atomic Emission Spectrometry (AES) and Mass Spectrometry (MS) will be described. It will be shown that ITV has the potential to cause a paradigm shift in classical elemental analysis by ICP spectrometry by taking analysts from the milli-size (e.g., mg or mL) to the micro-size (e.g., microgram of microL), sub-micro and even nano-sample size-regime. Despite the success of ITV with tiny amounts of sample, such samples must still be collected in the field and must be brought to the laboratory (albeit in smaller containers) for elemental analysis by ICP spectrometry. Would it not be ideal if we could bring an ICP spectrometer to the sample, thus obtaining analytical results in the field (i.e., on-site) and in (near) real-time? Since the typical ICP spectrometer is bulky and heavy and has kWatt power requirements, it is nearly always tethered to a wall socket and it is not usually taken out to the field. Do we need such a large instrument to analyze such tiny samples? In the second part of this paper, current research in my laboratories toward the conceptual goal of miniaturizing elemental analysis instrumentation will be presented. For this, development and characterization of a portable, battery-operated instrument for (near) real-time Hg determination in the field from gases and from liquid and solid micro-samples will be used as an example. Future portable elemental analysis micro-instruments that can be taken out of the lab and into the field are poised to cause another paradigm shift in classical elemental analysis by allowing analysts to bring (part of) the lab to the sample.
配备气动雾化进样的电感耦合等离子体（ICP）光谱仪需要几毫升的样品量。对于少量固体的直接元素分析，配备直接进样（DSI）或电热蒸发（ETV）进样系统的ICP通常需要毫克级的样品量。在我的实验室中，我们一直在开发和表征一种名为炬内蒸发（ITV）的新型进样系统。ITV进样系统显著提高了ICP光谱法（原子发射光谱法和质谱法）的检测限，从而能够对微米级和亚微米级的液体或固体样品进行测定。在某些情况下，甚至对微观的纳米级样品也成功进行了分析。在本文的第一部分，将描述用于原子发射光谱法（AES）和质谱法（MS）的ITV-ICP的开发情况。结果将表明，ITV有可能使ICP光谱法在经典元素分析中引发范式转变，将分析人员从毫克级（例如毫克或毫升）带入到微克级（例如微克或微升）、亚微米级甚至纳米级样品量的范围。尽管ITV在极少量样品分析方面取得了成功，但此类样品仍必须在现场采集，并带到实验室（尽管使用的容器较小）进行ICP光谱法元素分析。如果我们能将ICP光谱仪带到样品所在之处，从而在现场（即实地）并（近乎）实时获得分析结果，那岂不是很理想？由于典型的ICP光谱仪体积庞大、重量较重且需要千瓦级的功率，它几乎总是连接到墙上插座，通常不会拿到野外。我们真的需要这么大的仪器来分析如此微小的样品吗？在本文的第二部分，将介绍我实验室目前朝着实现元素分析仪器小型化这一概念目标所开展的研究。为此，将以开发和表征一种便携式、电池供电的仪器为例，该仪器用于现场对气体以及液体和固体微量样品进行（近乎）实时汞测定。未来能够带出实验室并进入现场的便携式元素分析微型仪器，有望通过让分析人员将（部分）实验室带到样品处，在经典元素分析中引发另一次范式转变。
