Detection range

Isotope Spin, I Receptivity ratio Reference compound Detection range, ppm V at 7.05 MHz" E... 

Several studies have been conducted to measure methyl parathion in streams, rivers, and lakes. A U.S. Geological Survey (USGS) of western streams detected methyl parathion in five river samples taken from four states during a 14-month period in 1970 and 1971. The amount of methyl parathion detected ranged from 0.04 to 0.23 pg/L (Schultz et al. 1973). A later and more extensive USGS study analyzed water samples from major rivers of the United States four times yearly in the period of 1975-1985. Of the 2,861 water samples, 0.1% had detectable levels of methyl parathion (Gilliom et al. 1985). In a study of Arkansas surface waters, samples of lake and river/stream water were collected and analyzed over a three-year period (Senseman et al. 1997). Of the 485 samples collected, methyl parathion was found in one river/stream sample at a maximum concentration of 3.5 pg/L. Results from an EPA study in California detected methyl parathion in 3 of 18 surface drain effluent samples at concentrations of 10-190 ng/kg. Subsurface drain effluent water had concentrations of 10-170 ng/kg in 8 of 60 samples (lARC 1983). 

As noted above, the presence of Met(O) in proteins would go undetected after acid hydrolysis and subsequent amino acid analysis. Thus, since this method of hydrolysis is most commonly used, it is impossible to ascertain from the literature the abundance of Met(O) residues normally present in proteins. However, a number of studies have reported the presence of Met(O) residues in various proteins using one of the appropriate procedures described above. It has been found that Met(O) residues comprise 30% of the total Met in proteins isolated from bovine glomerular basement membranes and anterior lens . Other investigators have reported that the levels of Met(O) in proteins of the trabecular meshwork of human eyes increased with the age of the donor . The amount of Met(O) detected ranged from 15% (10 years old) to 55% (79 years old) of the total methionine content found in the tissue samples. Other studies have shown that in certain species of clams the proteins of the hinge ligament contain only Met(0) residues and no Met . In addition, it has also been reported that as much as 18% of the Met residues in pea seed proteins is in the form of Met(O) . Lastly, Met(O) residues have been found in... 

Pollutant Samples Detections Range Median Mean... 

Pollutant Number of Samples/ Number of Detections Range of Detections Median of Detections Mean of Detections... 

Analytes Matrix Extraction method Detection Range of concentrations detected in the environment REF... 

Liu et al. [23] used a third-derivative spectrophotometric method for the determination of miconazole nitrate in Pikangshuang (cream). The detection range was 60-300 pg/mL and recovery was 100.1%. 

Figure 1. The detection range of various instruments, NL Natural radon concentration level.

The linear detection range in flow injection analysis was from 0.02 to 4.5mM (Fig. 16.8) with a sensitivity of 0.042 jA/mM and analytical time of 20 s per sample. 

Ghamouss [263] developed a screen-printed carbon electrode modified with both HRP and LOD (SPCE-HRP/LOD) to determine 1-lactate. The sensitivity of the optimized SPCE-HRP/LOD to 1-lactate was 0.84nAL jM 1 in a detection range between 10 and 180 pM. 

The interference from amino acids was investigated and found to be negligible as reported by Solorzano [37] and Haywood and Huyser [43], who employed no heating for the indophenol blue colour development. Solutions containing 50 xg N/l of urea, histidine, lycine, glycine, and alanine were analysed. The NH4-N detected ranged between 0.4% (for urea) and 2.2% (for alanine) of the nitrogen added. 

It is clear that the main performance criteria that must be taken into account when selecting a detector for a particular determination are selectivity and sensitivity, followed by linearity of signal response, linear detection range, and repro-... 

Of 47 congeners included in the analytical work, eight different PBDEs were detected, ranging from tetra- to deca-brominated compounds tetra-BDE-47, penta-BDE-99, penta-BDE-100, penta-BDE-118, hexa-BDE-153, hexa-BDE-154, hepta-BDE-183, and deca-BDE-209. However, BDE-99 could not be quantified due to coelutions with breakdown products of HBCD. This coelution has been previously described by Covaci et al. [32]. 

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