Sample introduction systems manufacturers

A schematic diagram of an ICP-MS instrument is shown in Fig. 5.1. The TCP part bears an almost exact resemblance to the ICP used for atomic emission spectrometry, with the obvious exception that it is turned on one side. Indeed, sample introduction systems, radiofrequency generators and the nature of ICP itself are often the same for ICP-MS and ICP-AES systems, with the usual variations between individual manufacturers. 

FIG. 1. Large-size furnace for solid sampling, manufactured by Grim Analytische Mess-Systeme G.m.b.H., Ehringshausen, Germany, model SM 20. The test substance is introduced either manually with a pincn- and the L vov platform, or by an automated sample introduction system. Dimensions of the furnace OD S3 mm and ID 10.5 mm. 

The first completely re-engineered laboratory-focused microwave system was introduced by Prolabo in 1986. Most commercial open-vessel microwave systems manufactured since then are of the focused-microwave type, i.e., they use the waveguide as a single-mode cavity. Since their introduction, they have widely been used for sample extraction, substituting in most cases the closed-vessels systems, which as of now are used mainly for carrying out sample digestions. 

Fig. 5.3 Overview of commercial instrument, lA-Lab (model L-250G-IA, manufactured by Canon Anelva, Kanagawa, JAPAN). This equipment consists of direct inlet probe (DIP), Li+ attachment reaction chamber with LP emitter in it, the ion focusing system, and the quadrupole mass spectrometer. Li+ is supplied by a Li+ emitter. There are two types of interface for sample introduction an introduction tube for gases and a direct inlet probe for solids and liquids. ( 2009, Canon Anelva, Data sheet)...

Several instrument manufacturers supply flame photometers designed specifically for the determination of sodium, potassium, lithium, and sometimes calcium in blood serum, urine, and other biological fluids. Single-channel and multichannel (two to four channels) instruments are available for these determinations. In the multichannel instruments, each channel can be used to determine a separate element without an internal standard, or one of the channels can be reserved for an internal standard such as lithium. The ratios of the signals from the other channels to the signal of the lithium channel are then taken to compensate for flame noise and noise from fluctuations in reagent flow rate. Flame photometers such as these have been coupled with flow injection systems to automate the sample-introduction process (see Section 33B-3). Typical precisions for flow-injection-analysis-based flame photometric determinations of lithium, sodium, and potassium in serum are on the order of a few percent or less. Automated flow injection procedures require l/KIO the amount of sample and 1/10 the time of batch procedures. -... 

Obviously, almost any technique to achieve the goals of ionization, separation and detection of ions in the gas phase can be applied - and actually has been applied -in mass spectrometry. Fortunately, there is a simple basic scheme that all mass spectrometers follow. A mass spectrometer consists of an ion source, a mass analyzer, and a detector which are operated under high vacuum conditions. A closer look at the front end of such a device might separate the steps of sample introduction, evaporation, and successive ionization or desorption/ionization, respectively, but it is not always trivial to identify each of these steps as clearly separated from each other. If the manufacturing date of the instrument is relatively recent, it will have a data system which collects and processes data from the detector. Since the 1990s, mass spectrometers are fully equipped and controlled by data systems (Fig. 1.3). 

With the increasing demand to analyze more and more samples, manufacturers of autosamplers and sample introduction accessories are designing automated sampling systems to maximize sample throughput. This is being achieved in a variety of different ways by optimizing the sample delivery process to reduce the pre- and postmeasurement time. Some typical optimization procedures include the following ... 

Successful flow cytometric analysis depends on adequate sample preparation (see Chapters 30-31), appropriate selection of probes or markers (see Subheading 2.), instrumentation, and data display and analysis. Each of these areas is interrelated and requires adequate attention to avoid the introduction of artifacts and misinterpretation of results. Flow cytometers tend to be excessively complicated and require a skilled operator for alignment and calibration, though manufacturers are introducing more compact, user-friendly data acquisition and image processing systems. 

The simplest type of batch high-pressure reactor is essentially a hollow cylinder with one or two end caps, often referred to as a pressure bomb. Such vessels can be purchased from a variety of manufacturers, including Parr, Autoclave Engineers, and Pressure Products Industries, to name just a few. These reactors typically are equipped with a stirring system, such as described in an earlier section, a heating jacket, and ports for introduction of a thermocouple, as well as addition or removal of samples. Sizes range typically from 50 mL up to several liters, and pressure and temperature ratings vary from one manufacturer to another. 

As mentioned in the Introduction to this chapter, development of new MS systems has focused on the ability to accurately measure smaller samples, either for greater sensitivity or shorter-lived radionuclides, and to more effectively individuate these samples. In addition to these advancements, refinements of the instrumentation are now allowing manufactures to scale down the size of their MS workstations. 

The brand of the HPLC system does not matter, many manufacturers produce excellent apparatus. A few key specifications are important, however, to perform the methods presented here. If large diameter columns (25-mm) are to be used, the pumps should support flow rates of 9 mL/min and the UV detector cell must be able to withstand back pressures generated by these high flow rates (refer to the appropriate operating manual or contact the manufacturer s technical representative). A solvent selection manifold, at least on the B pump, is helpful for sample loading (otherwise, the B pump solvent lead and filter must be cleaned after sample loading prior to introduction of the B solvent see Section 3.2.1.)... 

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