Three Different Spectrophotometric Methods for Simultaneous Determination of Pyriproxyfen and Chlorothalonil Residues in Cucumber and Cabbage Samples

Table 4

Percentage mean recovery of pyriproxyfen and chlorothalonil in real cabbage samples by proposed methods.

Pyriproxyfen
Fortification level (μg·mL^−1)	1st and 2nd derivatives						Ratio spectra derivative				Mean centering of ratio spectra
	^1D281.80 nm		^2D281.40 nm		^2D285.60 nm		^1DD272 nm		^1DD286 nm		278 nm
	%R	%RSD	%R	%RSD	%R	%RSD	%R	%RSD	%R	%RSD	%R	%RSD
3.0	85.27	4.23	82.12	4.08	85.57	4.59	83.51	4.37	85.29	4.66	88.69	4.06
20.0	95.50	2.09	95.36	3.19	94.84	3.15	93.88	4.36	96.10	2.84	95.34	2.93
30.0	97.40	2.04	96.33	2.05	95.61	2.21	91.32	3.50	96.98	2.08	95.95	2.37
Chlorothalonil
Fortification level (μg·mL^−1)	1st and 2nd derivatives						Ratio spectra derivative				Mean centering of ratio spectra
	^1D329.20 nm		^2D262.60 nm		^2D266 nm		^1DD228 nm		^1DD262 nm		254 nm
	%R	%RSD	%R	%RSD	%R	%RSD	%R	%RSD	%R	%RSD	%R	%RSD
1.0	90.89	4.58	86.24	5.14	85.00	5.37	84.33	5.03	91.14	4.60	89.17	4.02
4.0	96.65	2.42	92.10	3.71	95.79	3.02	92.16	3.03	95.86	2.52	95.17	2.67
7.0	94.95	2.24	93.08	2.90	94.03	2.53	91.87	2.39	96.30	2.18	95.75	2.04