Inductively coupled plasma detection limit estimates

This method was developed as a second independent method to complement the usual colorimetric procedure in the determination of a certified concentration of dissolved silica in a seawater reference material. Ion exclusion affords a separation of the dissolved silica not only from major seawater cations but also from potentially interfering anions. The detection unit limit, conservatively estimated at 2.3 ng/g Si (0.08. im), is superior to that achievable by direct analysis using inductively coupled plasma emission spectrometry. 

Equation 8.3 relies on the assumption that the calibration parameters hold to the limit of detection, which is not necessarily correct. If the calibration is taken over a very wide range, for example in some element analyses by inductively coupled plasma, the uncertainty is not constant but is proportional to the concentration. In this case it is not possible to estimate the detection limit by equation (8.3). 

Maneb or mancozeb. Headley (1996) used an inductively coupled plasma-atomic emission spectrometry (ICP-AES) method for occupational exposure estimations that measures mancozeb by determining the elemental manganese portion of the pesticide in a sample. The method was successful in analyzing urine (0.02 mg/L), wash water (0.02 mg/L), tank mixes (0.02 mg/L), cellulose acetate filters (0.5 pg), and fabric from patches and clothing (0.5 pg), with detection limits in parentheses. However, ICP-AES methods cannot differentiate among various forms of manganese, so it is important that background... 

Some of the problems In forensic analysis related to sample matrix and detection limits can be found In other analytical laboratories as well. Besides the enhancement and suppression effects on analyte signals described by Mr. Mldklff In the previous section. Dr. Watters and Ms. Wood of the National Bureau of Standards provide some specific Information regarding matrix effects on spectral background. Background level and spectral structure comprise the chief source of measured signal when blanks are being measured for detection limit estimation. Their example Is taken from Inductively coupled plasma (ICP) spectrometry. 

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