Detection capability definition

The boundaries of trace analysis are described by the definition of trace element in the IUPAC Compendium of Chemical Terminology, 2nd edition Any element having an average concentration of less than about 100 parts per million atoms and less than 100pg g As analytical techniques have become more sophisticated and detection capabilities have improved, this upper boundary of the definition of trace is now so far away from the capabilities of analysis in a number of fields that new terms such as ultratrace analysis have entered common parlance. There is no agreement, however, on the range of ultratrace analysis, and this term has no rigorous definition. In the literature, the term is used to define the presence of elements at mass fractions less than 10 6 and 10 8 (1 pg g 1 and 0.01 pg g ) ... 

One of the most important performance characteristics in residue analysis is certainly the detection capability of a method. Unfortunately, many different definitions with regard to the detection and quantifying capability of an analytical method are found in the literature. Attempts have been made to harmonize the definitions with regard to the limit of detection (LoD) and the limit of quantification (LoQ). For the sake of consistency, here reference is made only to the harmonized definitions of IUPAC and ISO for the detection decision (Lc, critical value), LoD (minimum detectable value) and LoQ (minimum quantifiable value) (45 -47). ISO terminology is given between brackets. 

It is also important to understand that an additional role of the ion optic system is to stop particulates and neutral species from making it through to the detector, which would increase the noise of the background signal. This will certainly impact the instrument s detection capability in the presence of complex matrices. Therefore, it is definitely worth carrying ont a DL test in a difficult matrix such as lead or uranium, which tests the ability of the ion optics to transport the maximum number of analyte ions while rejecting the maximum number of matrix ions, neutral species, and particulates. 

Studies which perform analysis of the detection capabilities and rank various AVs are very common. One such study, which provides analysis of at risk time for single AVs, is given in [10]. Several sites report rankings and comparisons of AVs, though readers should be careful about the definitions of system under test when comparing the results from different reports. 

VII-3.3.1 Definition. This survey is a sampling of the subsurface atmosphere with a gas detector or other device capable of detecting 0.5% hydrogen gas in air at the sample point. 

VII-3.7.1 Definition. This is the testing of exposed piping facilities with an instrument capable of detecting the ultrasonic energy generated by escaping gas. The instrument used shall be suitable for the pressure... 

The device proposed by Pawliszyn, based on the establishment of a concentration gradient, complies more strictly with the definition of sensor. However, it can only be used with detection techniques capable of probing the typically small volumes associated with diffusion layers, which are most... 

ISO 11843-1 1997 Capability of Detection. Part 1 Terms and Definitions, International Organization for Standardixation, Geneva, 1997. 

Comparing detection limits is always a hazardous business. Different workers measure them under different circumstances and even with different definitions of the quantity being measured. Partisan bias cannot be ruled out, and reproducibility from worker to worker leaves much to be desired. Nevertheless, the figures in Table I should give a fairly realistic picture of the comparative capabilities of the four methods. 

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