Corn detection

Colorless gas with an odor like new mown grass or green corn detectable at 0.4-1.5 ppm. At high concentration, the odor may be strong, stifling, and unpleasant. Eyes, nose, and throat become irritated at 3-4 ppm. 

Colorless liquid with an odor like new mown grass or green corn detectable at 0.5 ppm. 

Similarly, after a longer time of incubation, no significant changes in the cell proliferation rate was detected, as can be seen in the data for 72 h (Figure 13). In fact, this was expected due to the biocompatible nature of xylan. As a natural polyssacharide, this type of biomaterial is considered to be highly stable, non-toxic and hydrophilic (Liu et al., 2008). Accordingly, the alkaline extraction of xylan from corn has proved to be a safe approach for obtaining the polymer with no relevant toxicity (Unpublished data). 

Separation and detection methods The common methods used to separate the Cr(III)/(VI) species are solvent extraction, chromatography and coprecipitation. In case of Cr(VI) from welding fumes trapped on a filter, a suitable leaching of the Cr(VI) from the sample matrix is needed, without reducing the Cr(VI) species. The most used detection methods for chromium are graphite furnace AAS, chemiluminescence, electrochemical methods, ICP-MS, thermal ionization isotope dilution mass spectrometry and spectrophotometry (Vercoutere and Cornelis 1995)- The separation of the two species is the most delicate part of the procedure. 

Third, the bulk of the items in Table 1 address method performance. These requirements must be satisfied on a substrate-by-substrate basis to address substrate-specific interferences. As discussed above, interferences are best dealt with by application of conventional sample preparation techniques use of blank substrate to account for background interferences is not permitted. The analyst must establish a limit of detection (LOD), the lowest standard concentration that yields a signal that can be differentiated from background, and an LOQ (the reader is referred to Brady for a discussion of different techniques used to determine the LOD for immunoassays). For example, analysis of a variety of corn fractions requires the generation of LOD and LOQ data for each fraction. Procedural recoveries must accompany each analytical set and be based on fresh fortification of substrate prior to extraction. Recovery samples serve to confirm that the extraction and cleanup procedures were conducted correctly for all samples in each set of analyses. Carrying control substrate through the analytical procedure is good practice if practicable. 

The recoveries from untreated control samples fortified with fluthiacet-methyl at 0.2mgkg were 96% [relative standard deviation (RSD) 3.1%] for corn and 74% (RSD 8.0%) for green corn. The limit of detection was 0.01 mg kg 7 The recoveries from untreated control soils fortified with fluthiacet-methyl at 0.1 and 0.2mgkg were 85-103% and 87-103%, respectively. The limit of detection was 0.01 mgkg 7... 

After use, herbicides decompose slowly, and so affect cultivated plants for many years. In 1990, investigations in many regions of the USSR detected herbicides phytotoxic effects, especially among the si/m-triazine class, on different cultivars in many varied situations [13]. These sym-triazine herbicides, such as protrazin, simazin, atrazine, metazin, and prometrin, were used in different oblasts of the Ukraine, Kirgizia, Kazakhstan, Russia and Moldavia in previous years, especially on corn. Residual herbicide aftereffects led to the suppression and death of crops such as winter wheat, oats, barley, rye, potatoes, beets and sugar beets, linen, onions, watermelons and other melons, and sunflowers. 

Visconti A, Pascale M (1998) Determination of zearalenone in corn by means of immunoaffinity clean-up and high-performance liquid chromatography with fluorescence detection. 

Honey and maple syrup are complex products of high market price (813C — 23%o). The main source of adulteration is cheap high fructose corn syrup (813C — 13%o) or cane sugar (813C —ll%o) and the adulterated product is easily detected at levels as low as 10% or so of added sugar. 

No studies were located in humans regarding the distribution of 1,2-dibromoethane after oral exposure. In humans intentionally ingesting 1,2-dibromoethane, kidney lesions and centrilobular necrosis of the liver were found (Olmstead 1960 Saraswat et al. 1986). This is indirect evidence of distribution of 1,2-dibromoethane. The tissue distribution of 1,2-dibromoethane has been studied in rats following exposure by the oral route. Although retention was limited, the kidneys, liver, and spleen appear to retain the highest amounts of the administered dose (Plotnick et al. 1979) as illustrated in Table 2-4. Rats received an oral dose of 15 mg/kg/day of labeled 1,2-dibromoethane in corn oil. Twenty-four hours later 3% of radioactivity was detected in fat, brain, kidney, liver, spleen, testes, blood, and plasma, 72.38% in the urine, and 1.65% in the feces (Plotnick et al. 1979). By 48 hours after administration, 73% of the radiolabeled dose was accounted for in the urine, 1.1% in the liver, and 2.4% in the feces. Total recovery was 77.8% of the administered radioactivity. 

Most manufacturing processes do not detoxify aflatoxin and therefore if the aflatoxins are not detected, products will be marketed. One of the processes used for reducing aflatoxin levels is nixtamalization (alkaline cooking), which is used during the making of corn tortillas, tortilla chips, and corn chips, and gives a 51 to 78% reduction in aflatoxin levels (Torres et al., 2001). 

Source Indole was detected in jasmine flowers Jasminum officinale), licorice [Glycyrrhiza glabra), kohlrabi stems [Brassica oleraceavAT. gongylodes), and hyacinth flowers Hyacinthus orientalid at concentrations of 42 to 95, 2, 1.33, and 0.24 to 3.45 ppm, respectively. Indole also occurs in tea leaves, black locust flowers, corn leaves, petitgrain, and yellow elder (Duke, 1992). 

Muir, D.C.G. and Baker, B.E. Detection of triazine herbicides and their degradation products in tile-drain water from fields under corn (maize) production, J. Agric. Food Chem., 21(1) 122-125, 1976. 

Most of the applications of HPLC for protein analysis deal with the storage proteins in cereals (wheat, corn, rice, oat, barley) and beans (pea, soybeans). HPLC has proved useful for cultivar identihcation, protein separation, and characterization to detect adulterations (illegal addition of common wheat flour to durum wheat flour) [107]. Recently Losso et al. [146] have reported a rapid method for rice prolamin separation by perfusion chromatography on a RP POROS RH/2 column (UV detection at 230nm), sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis (PAGE), and molecular size determination by MALDl-MS. DuPont et al. [147] used a combination of RP-HPLC and SDS-PAGE to determine the composition of wheat flour proteins previously fractionated by sequential extraction. 

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