Extraction and Chromatographic Determination of Shikimic Acid in Chinese Conifer Needles with 1-Benzyl-3-methylimidazolium Bromide Ionic Liquid Aqueous Solutions
Table 1
Experimental design matrix to screen for variables that determine the extraction yield of shikimic acid from Picea meyeri needles and ANOVA resultsa.
Run
BBD experiments
ANOVA
(min)
(W)
(mL/g)
Y (mg/g)
Source
Sum of squares
Degree of freedom
Mean square
F value
value
1
40
200
12
17.92
Modelb
15.50
9
1.72
4.63
0.0278c
2
20
200
12
16.51
3.80
1
3.80
10.21
0.0152c
3
30
200
10
16.80
0.03
1
0.03
0.09
0.7761
4
20
150
10
15.37
0.02
1
0.02
0.06
0.8184
5
40
250
10
16.20
3.37
1
3.37
9.06
0.0197c
6
40
200
8
17.97
0.30
1
0.30
0.80
0.4007
7
30
250
12
16.85
6.33
1
6.33
17.02
0.0044c
8
20
250
10
17.24
1.09
1
1.09
2.94
0.1302
9
20
200
8
15.47
0.59
1
0.59
1.59
0.2472
10
30
200
10
15.62
0.05
1
0.05
0.14
0.7200
11
30
150
8
17.83
Residual
2.60
7
0.37
12
40
150
10
18.00
Lack of fit
1.43
3
0.48
1.62
0.3186
13
30
200
10
16.63
Pure error
1.18
4
0.29
14
30
200
10
16.83
Cor. total
18.11
16
15
30
150
12
14.62
16
30
250
8
15.03
17
30
200
10
16.97
Credibility analysis of the regression equations
Index mark
Standard deviation
Mean
Coefficient of variation%
Adequacy precision
Y
0.61
16.58
3.68
0.8562
7.6139
The results were obtained with Design Expert 7.0 software.
b is the ultrasound irradiation time (min), is the ultrasound irradiation power (W), is the liquid-solid ratio (mL/g), and Y is the extraction yield (mg/g).
cSignificant at .
