02306naa a2200301 a 450000100080000000500110000800800410001902400260006010000270008624501440011326000090025752013510026665000200161765300280163765300250166565300140169065300260170465300330173065300290176365300270179265300200181970000130183970000140185270000240186670000180189070000320190877300640194020048252016-02-18       2014    bl uuuu     u00u1 u    #d7 a10.1002/cem.26392DOI1 aNEVES JUNIOR, A. C. V.  aResponse surface methodology for optimization of cyanamide analysis by in situ derivatization and dispersive liquid-liquid microextraction.  c2014  aCyanamide is widely used for agricultural purposes; therefore, its residues can be found in water. A new method was developed for its quantification usingin situ derivatization with 2,6-dimethyl-4-quinolinecarboxylic acid N-hydroxysuccinimide ester followed by dispersive liquid–liquid microextraction (DLLME) and high-performance liquid chromatography/fluorescence analysis. Multivariate chemometric techniques were successfully used to obtain the optimum conditions for direct derivatization and DLLME extraction. Derivatization parameters and DLLME extraction conditions were optimized by a two-step design, 2k factorial design for screening, and central composite design for optimization. Best derivatization conditions were addition of 600?L of derivatizing reagent, a temperature of 4ºC, and pH 8.5, whereas for optimum extraction 800?L of solvent, 30% NaCl conc. w/v, and pH 3.8 were chosen. The analytical performance of the method for routine analysis was evaluated. Excellent linearity was achieved from 10 to 200?gL -1with a correlation factor of 0.9996. Precision ranged from 3.5% to 5.5% for intraday assays and 8.5% to 8.6% for interday assays. The mean recoveries performed on water from different origins (ground, river,sea, tap, and mineral) at three levels of concentration (20, 75, and 200?gL-1) ranged from 90.2% to 110.2%.  amicroextraction  aAnálise quimiométrico  aChemometric analyses  aCyanamide  aDerivazação in situ  aDispersão líquido-líquido  aDispersive liquid-liquid  aIn situ derivatization  aMicroextração1 aMELO, A.1 aPINHO, C.1 aCONEGLIAN, R. C. C.1 aSOARES, A. G.1 aFERREIRA, I. M. P. L. V. O.  tJournal of chemometricsgv. 28, n. 9, p. 716-724, may 2014.