Sample types atmospheric

The main reason for sampling for atmospheric particulates is to estimate the concentrations that are inhaled and deposited in the lungs. Sampling methods and the interpretation of data relevant to health hazards are relatively complex industrial hygienists, who are specialists in this technology, should be consulted when confronted with this type of problem. 

Fig. 1.1. General scheme of a mass spectrometer. Often, several types of sample inlets are attached to the ion source housing. Transfer of the sample from atmospheric pressure to the high vacuum of the ion source and mass analyzer is accomplished by use of a vacuum lock (Chap. 5.3).

One of the most challenging aspects of atomic spectrometry is the incredibly wide variety of sample types that require elemental analysis. Samples cover the gamut of solids, liquids, and gases. By the nature of most modem spectrochemical methods, the latter two states are much more readily presented to sources that operate at atmospheric pressure. The most widely used of these techniques are flame and graphite furnace atomic absorption spectrophotometry (FAAS and GF-AAS) [1,2] and inductively coupled plasma atomic emission and mass spectrometries (ICP-AES and MS) [3-5]. As described in other chapters of this volume, ICP-MS is the workhorse technique for the trace element analysis of samples in the solution phase—either those that are native liquids or solids that are subjected to some sort of dissolution procedure. 

It is important to emphasize that a discussion of the problems associated with marine shell could be repeated for any sample type/geo-chemical environment where the contemporary radiocarbon values may not be in equilibrium with the atmosphere. In such cases, a specific contemporary standard must be used for each sample type or geochemical environment which can be related to the terrestrial biological radiocarbon standard. Special standards and/or correction values would, for example, be required for specifically defined oceanographic regions in the case of marine shell, standards for specific fresh water shell or gastropod geochemical environments, standards for Arctic and Antarctic specimens, and specific soil carbonate environments (75). 

Thus a feedstock map can be used to show where a particular physical or chemical property tends to concentrate on the map. For example, the coke-forming propensity, that is, the amount of the carbon residue, is shown for various regions on the map for a sample of atmospheric residuum (Fig. 2.7 Long and Speight, 1998). In addition, a feedstock map can be very useful for predicting the effectiveness of various types of separations processes as applied to petroleum (Fig. 2.8 Speight, 2001). 

In the present work, a series of samples were prepared and evaluated in a flow- type atmospheric glass reactor using different ethanol water feed compositions over a wide range of space velocities. The evaluation conditions were simulated to commercial plants with an object to develop a recipe suitable for commercial use.... 

The identification of sediment-derived atmospheric Kr and Xe in some sample types means that the extension of solubility fractionation models (that assume a priori a groundwater origin for all atmospheric noble gases) to include Kr and Xe has to be assessed with caution on a case-by-case basis. 

Malanchuk, M. Evaluation of Two Filter Material Types for Sampling Test Atmospheres, Amer. Lab. Dec, 92 (1982)... 

The efficient transfer of an analyte from its original condition to the ionization region of an ion mobility spectrometer (IMS) is the topic of this chapter. Snccessfnl detection and identification of an analyte by IMS depend on many steps but none more important than those by which a sample is introduced into an instrument. IMS instruments are used for the detection and identification of analytes found in air, water, biological fiuids and tissues, industrial solvents and on surfaces. Because ion mobility spectrometry is such a universal analytical instrument, sample introduction methods are diverse and depend on the type of sample analyzed. Atmospheric pressure operation makes IMS suitable for interfacing with several sample introduction systems as a detector as well as a selective filter for mass spectrometric techniques. 

Tg values are averages based on a minimum of six determinations. Various combinations of heating rate (2-10°C/min.), sample mode and sample type. Nitrogen atmosphere in all cases. 

Static sampling systems are defined as those that do not have an active air-moving component, such as the pump, to pull a sample to the collection medium. This type of sampling system has been used for over 100 years. Examples include the lead peroxide candle used to detect the presence of SO2 in the atmosphere and the dust-fall bucket and trays or slides coated with a viscous material used to detect particulate matter. This type of system suffers from inability to quantify the amount of pollutant present over a short period of time, i.e., less than 1 week. The potentially desirable characteristics of a static sampling system have led to further developments in this type of technology to provide quantitative information on pollutant concentrations over a fked period of time. Static sampling systems have been developed for use in the occupational environment and are also used to measure the exposure levels in the general community, e.g., radon gas in residences. 

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