Nitrofen Concentration

A 100-mL volume of benzene is added to the 20 g of air-dried soil and the mixture is shaken vigorously for 2h. After extraction twice with 100 mL of benzene, the combined extract is filtered through filter paper and the filter cake is washed with an additional 20 mL of benzene. The benzene extracts are dried over anhydrous Na2S04 and concentrated to dryness using a vacuum rotary evaporator. The residue is dissolved in an appropriate volume followed by GC/ECD analysis. For the monitoring of pesticide residues in soil, methanol for bifenox and oxyfluorfen and acetonitrile for nitrofen were recommended as the solvents for efficient extraction. ... 

The GC/FID conditions were as follows column, 1.5% OV-17 (2 m x 3-mm i.d.) glass column N2 carrier gas flow rate, 45mLmin temperature of injection port, column and detector, 240,235 and 235 °C, respectively. The recoveries of these amino derivatives with fortification level ranging from 0.5 to lO.Omgkg" were 62-101% for chlornitrofen, 62-101% for nitrofen and 58-101% for chlomethoxyfen, and satisfactory recoveries from soil were obtained at high concentrations, but the recoveries at lower concentration averaged about 66% for the least recovered compound. Interference from other substances in the soil extracts derived from the acetylation reaction was negligible. 

Nitrofen is weakly toxic to m mals. The acute oral for rats is 2630 mg/kg. Neither the active ingredient nor the formulation emulsifiable concentrate caused irritation to rabbit skin. Rats on dietary levels of 100 and 500 ppm for 13 weeks and on 10 100 and 1000 ppm for 97 weeks showed no definite differences in growth, feed consumption or mortality, when compared to controls (Ambrose et al., 1971). 

Chemicals listed in Table I have been tested for their effects on chlorophyll fluorescence. All chemicals show prompt fluorescence kinetics similar to that of DCMU, except for nitrofen and trifluralin which are excluded from the group of so-called DCMU-type inhibitors . A quantitative relationship between inhibitor concentration and selected fluorescence parameters has been researched. 

Figure 5. Addition of nitrofen to isolated spinach chloroplasts in the light and in the dark. Thylakoids equivalent to 100 fig of chlorophyll were incubated at pH 7.4 in the presence of 50 /nM C-labeled nitrofen for 15 min. Aliquots of this preloaded material were then treated with increasing concentrations of cold nitrofen as indicated (37).

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