Water chlorophenoxy acid residues

Figure 13.11 Column-switcliing RPLC trace of a surface water sample spiked with eight chlorophenoxyacid herbicides at the 0.5 p-g 1 level 1, 2,4-dichlorophenoxyacetic acid 2, 4-chloro-2-methylphenoxyacetic acid 3, 2-(2,4-diclilorophenoxy) propanoic acid 4, 2-(4-cliloro-2-methylphenoxy) propanoic acid 5, 2,4,5-trichlorophenoxyacetic acid 6, 4-(2,4-dichlorophenoxy) butanoic acid 7, 4-(4-chloro-2-methylphenoxy) butanoic acid 8, 2-(2,4,5-tiichlorophenoxy) propionic acid. Reprinted from Analytica Chimica Acta, 283, J. V. Sancho-Llopis et al., Rapid method for the determination of eight chlorophenoxy acid residues in environmental water samples using off-line solid-phase extraction and on-line selective precolumn switcliing , pp. 287-296, copyright 1993, with permission from Elsevier Science.

J. V. Sancho-Llopis, F. Hernandez-Hernandez, E. A. Hogendoorn and P. van Zoonen, Rapid method for the determination of eight chlorophenoxy acid residues in environmental water samples using off-line solid-phase extraction and on-line selective precolumn switching , Anal. Chim. Acta 283 287-296(1993). 

A mixture of 22 grams of Oi-(p-chlorophenoxy)isobutyric acid, 3.8 grams of 1,3-propane-dioi, 0.5 gram of p-toiuenesulfonic acid and 150 ml of xylene was refluxed. When the theoretically calculated amount of water had been removed, the xylene solution was washed with dilute aqueous sodium bicarbonate and then the xylene was distilled off. The residue was distilled under reduced pressure to give 11 grams (47% yield) of 1,3-propanediol bis[a-(p-chlorophenoxy)isobutyrate] boiling at 197° to 200°C/0.03 mm Hg. 

In 1 L of water there is dissolved 116.0 g (1 mole) of N,N-diethylethylenediamine and, under vigorous stirring at a temperature maintained below 50°C, there is added 205.0 g (1 mole) of the chloride of p-chlorphenoxyacetic acid. The solution becomes rapidly homogeneous the formation of the basic amide hydrochloride is rapidly completed by further stirring the reaction mixture for 2 h at about 20°C. Then an excess of soda lye is added and the basic amide formed is extracted by ether. The ethereal solution is dried on anhydrous sodium sulfate and ether is distilled after that the residue is dried. So 2-(p-chlorophenoxy)-N-(2-(diethylamino)ethyl) acetamide is obtained. 

Butz, S. Stan, H.-J. Determination of chlorophenoxy 23. and other acidic herbicide residues in ground water by capillary GC of their alkyl esters formed by rapid derivatization using various chloroformates. J. Chromatogr. 24. 1993, 643, 111-13%. 

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