Three Different Spectrophotometric Methods for Simultaneous Determination of Pyriproxyfen and Chlorothalonil Residues in Cucumber and Cabbage Samples
Table 1
The statistical parameter for determination of pyriproxyfen and chlorothalonil by proposed methods.
Methods
Compounds
λmax (nm)
Linearity (mg·kg−1)
Regression equation
r2
LOD (mg·kg−1)
LOQ (mg·kg−1)
RSD (%)
Zero crossing
Pyriproxyfen
1D281.80
1.0–30.0
y = 2.209x + 0.5061
0.9996
0.312
0.946
1.52
2D281.40
y = 1.7735x − 0.8171
0.9996
0.254
0.772
1.38
2D285.60
y = 1.7656x + 0.1967
0.9998
0.256
0.776
2.04
Chlorothalonil
1D329.20
0.5–7.0
y = 6.5735x + 0.6716
0.9998
0.112
0.340
0.98
2D262.60
y = 4.1633x + 0.6333
0.9994
0.141
0.427
1.85
2D266
y = 3.3325x + 1.5971
0.9992
0.154
0.469
1.80
RSD
Pyriproxyfen
1DD272
1.0–30.0
y = 0.1592x − 0.0294
0.9997
0.270
0.818
0.83
1DD286
y = 0.1268x + 0.017
0.9998
0.302
0.917
0.52
Chlorothalonil
1DD228
0.5–7.0
y = 0.0162x + 0.0016
0.9996
0.144
0.436
1.59
1DD262
y = 0.0192x + 0.0047
0.9997
0.153
0.465
1.33
MCRS
Pyriproxyfen
278
1.0–30.0
y = 1.8125x − 0.1802
0.9998
0.211
0.641
1.73
Chlorothalonil
254
0.5–7.0
y = 0.2224x + 0.0935
0.9997
0.131
0.398
1.26
RSD: ratio spectra derivative method; MCRS: mean centering of the ratio spectra method; RSD%: percentage relative standard deviation; LOD: limits of detection; LOQ: limits of quantification.
