指示剂3:儿茶酚紫指示剂的CIE 1976(L*,a*,b*)色空间数字化特征
前言
图1. 儿茶酚紫的化学结构式
图2. 儿茶酚紫指示剂在pH环境的吸收曲线
图2显示,儿茶酚紫在不同pH值的溶液中的最大吸收峰是不同的。当pH值增加时,吸收峰向短波长方向移动。在pH1、pH2时,吸收峰的波长是510 nm;在pH3时,吸收峰向短波长方向移动,最大吸收峰在480 nm;pH4以后,最大吸收峰在450nm左右不变,说明分子结构在pH3和pH4之间发生的变化已经趋于稳定,不在变化。表1. 不同PH环境下儿茶酚紫指示剂最大吸收峰的变化
波长 | PH1 | PH 2 | PH 3 | PH 4 | PH 5 | PH 6 | PH 7 | PH 8 | PH 9 | PH 10 | PH 11 | PH 12 |
450 | 0.87698 | 0.78205 | 1.49027 | 3.03053 | 4.23431 | 2.12599 | 1.69417 | 2.59834 | 1.97875 | 2.92285 | 2.96589 | 3.26380 |
480 | 2.41023 | 1.85211 | 1.72642 | 2.28492 | 3.31682 | 1.48004 | 1.17204 | 1.82234 | 1.38625 | 2.11591 | 2.14242 | 2.40173 |
510 | 3.77635 | 2.78515 | 1.66458 | 0.89892 | 1.23378 | 0.37981 | 0.28561 | 0.49093 | 0.36455 | 0.65573 | 0.65576 | 0.77114 |
表2. 儿茶酚紫指示剂的色度值变化
PH | L*ab | a* | b* | C* | H* |
0.0 | 1.00 | 0.00 | 0.00 | 0.000 | 0.000 |
0.4 | 100.41 | 0.83 | -2.58 | 2.711 | -1.258 |
0.5 | 99.93 | 3.57 | -5.37 | 6.445 | -0.984 |
0.6 | 99.84 | 3.69 | -5.37 | 6.521 | -0.969 |
0.6 | 100.00 | 3.01 | -5.40 | 6.179 | -1.062 |
0.7 | 100.00 | 2.79 | -5.85 | 6.480 | -1.126 |
0.8 | 100.00 | 2.28 | -5.95 | 6.373 | -1.205 |
0.9 | 100.00 | 1.79 | -5.86 | 6.124 | -1.273 |
1.0 | 100.01 | 1.65 | -6.06 | 6.280 | -1.306 |
1.1 | 100.01 | 0.99 | -5.78 | 5.868 | -1.402 |
1.2 | 100.01 | 0.62 | -6.04 | 6.070 | -1.468 |
1.3 | 100.02 | 0.15 | -5.98 | 5.983 | -1.547 |
1.4 | 100.03 | -0.57 | -5.64 | 5.668 | 1.471 |
1.5 | 100.03 | -1.08 | -5.58 | 5.680 | 1.379 |
1.6 | 100.05 | -1.76 | -5.79 | 6.053 | 1.275 |
1.7 | 100.05 | -2.56 | -5.14 | 5.739 | 1.108 |
1.8 | 100.07 | -2.91 | -5.15 | 5.916 | 1.056 |
1.9 | 100.08 | -4.04 | -4.52 | 6.063 | 0.841 |
2.0 | 100.09 | -4.85 | -3.89 | 6.213 | 0.676 |
2.1 | 100.11 | -5.51 | -3.76 | 6.671 | 0.600 |
2.2 | 99.87 | -6.75 | -2.62 | 7.244 | 0.370 |
2.3 | 99.85 | -7.58 | -2.38 | 7.941 | 0.304 |
2.4 | 99.82 | -9.00 | -1.35 | 9.102 | 0.149 |
2.5 | 99.79 | -10.15 | -0.55 | 10.162 | 0.055 |
2.6 | 99.76 | -11.69 | 0.68 | 11.705 | -0.058 |
2.7 | 99.74 | -12.53 | 1.33 | 12.597 | -0.106 |
2.8 | 99.70 | -13.97 | 2.05 | 14.121 | -0.146 |
2.9 | 99.66 | -15.91 | 3.46 | 16.281 | -0.214 |
3.0 | 99.62 | -17.34 | 4.63 | 17.947 | -0.261 |
3.1 | 99.58 | -19.08 | 5.90 | 19.969 | -0.300 |
3.2 | 99.53 | -21.06 | 7.44 | 22.332 | -0.340 |
3.4 | 99.43 | -24.23 | 9.54 | 26.041 | -0.375 |
3.7 | 99.38 | -25.86 | 10.88 | 28.058 | -0.398 |
3.8 | 99.36 | -26.64 | 11.33 | 28.951 | -0.402 |
3.9 | 99.32 | -27.69 | 12.05 | 30.193 | -0.410 |
4.0 | 99.31 | -28.06 | 12.14 | 30.570 | -0.408 |
4.1 | 99.28 | -28.67 | 12.51 | 31.282 | -0.411 |
4.2 | 99.27 | -29.00 | 12.74 | 31.675 | -0.414 |
4.3 | 99.26 | -29.48 | 13.20 | 32.301 | -0.421 |
4.4 | 99.23 | -29.94 | 13.18 | 32.715 | -0.415 |
5.3 | 99.22 | -30.29 | 13.17 | 33.027 | -0.410 |
5.2 | 99.22 | -30.86 | 14.05 | 33.907 | -0.427 |
5.6 | 99.21 | -30.94 | 13.80 | 33.875 | -0.420 |
5.8 | 99.20 | -30.98 | 13.71 | 33.877 | -0.417 |
6.3 | 99.22 | -31.11 | 14.13 | 34.166 | -0.426 |
6.9 | 99.23 | -31.06 | 14.20 | 34.157 | -0.429 |
7.6 | 99.25 | -30.85 | 14.19 | 33.960 | -0.431 |
8.5 | 99.26 | -30.91 | 14.35 | 34.082 | -0.435 |
9.2 | 99.27 | -30.85 | 14.30 | 34.005 | -0.434 |
9.5 | 99.29 | -30.78 | 14.54 | 34.040 | -0.441 |
9.8 | 99.28 | -30.85 | 14.34 | 34.020 | -0.435 |
9.9 | 99.29 | -30.91 | 14.53 | 34.154 | -0.439 |
10.0 | 99.32 | -30.71 | 14.45 | 33.940 | -0.440 |
10.1 | 99.34 | -30.80 | 14.57 | 34.076 | -0.442 |
10.2 | 99.35 | -30.64 | 14.42 | 33.866 | -0.440 |
10.3 | 99.37 | -30.64 | 14.35 | 33.834 | -0.438 |
10.4 | 99.41 | -30.31 | 13.88 | 33.335 | -0.430 |
10.5 | 99.46 | -30.32 | 14.44 | 33.581 | -0.444 |
10.6 | 99.57 | -29.79 | 14.82 | 33.274 | -0.462 |
10.7 | 99.82 | -28.21 | 15.37 | 32.121 | -0.499 |
10.8 | 99.97 | -26.79 | 17.21 | 31.839 | -0.571 |
10.9 | 98.17 | -24.65 | 17.48 | 30.223 | -0.617 |
11.0 | 97.11 | -23.89 | 16.84 | 29.229 | -0.614 |
11.1 | 96.43 | -23.67 | 16.42 | 28.805 | -0.607 |
11.2 | 94.88 | -23.25 | 16.48 | 28.498 | -0.617 |
11.3 | 93.72 | -22.95 | 16.05 | 28.010 | -0.610 |
11.4 | 93.08 | -22.52 | 15.65 | 27.425 | -0.607 |
11.5 | 92.64 | -22.24 | 16.10 | 27.457 | -0.627 |
11.6 | 92.07 | -22.02 | 16.65 | 27.609 | -0.647 |
11.7 | 92.98 | -22.13 | 16.60 | 27.665 | -0.644 |
11.8 | 93.95 | -22.38 | 16.24 | 27.652 | -0.628 |
11.9 | 95.48 | -22.99 | 16.62 | 28.369 | -0.626 |
12.0 | 97.47 | -23.48 | 16.19 | 28.519 | -0.604 |
12.1 | 99.16 | -23.93 | 17.13 | 29.428 | -0.621 |
12.2 | 100.00 | -24.17 | 17.48 | 29.828 | -0.626 |
12.3 | 99.99 | -23.81 | 17.71 | 29.677 | -0.640 |
12.4 | 99.17 | -23.53 | 18.00 | 29.624 | -0.653 |
12.5 | 97.52 | -22.56 | 16.68 | 28.058 | -0.637 |
12.6 | 94.22 | -20.97 | 15.56 | 26.112 | -0.639 |
12.7 | 93.70 | -20.95 | 15.73 | 26.203 | -0.644 |
图3. 儿茶酚紫指示剂在不同pH环境的CIE 1976(L*,a*,b*)参数(L*,a*,b*、C*、H*)—pH曲线
图4. 儿茶酚紫指示剂在不同pH环境的CIE 1976(L*,a*,b*)参数(△E1、△E1-V、△E2、△E2φ、△E2α、△E2-V、△E3、△E3-V)—pH曲线
图5. 儿茶酚紫指示剂在不同pH环境的CIE 1976(L*,a*,b*)参数(σE、σL*、σa*、σb*、σC*、σH*)—pH曲线
图3-1. 儿茶酚紫指示剂在不同pH环境的CIE 1976(L*,a*,b*)参数(L*)—pH曲线
图3-2. 儿茶酚紫指示剂在不同pH环境的CIE 1976(L*,a*,b*)参数(a*,b*)—pH曲线
图3-3. 儿茶酚紫指示剂在不同pH环境的CIE 1976(L*,a*,b*)参数(C*、H*)—pH曲线
图3-4. 儿茶酚紫指示剂在不同pH环境的CIE 1976(L*,a*,b*)参数(H*)—pH曲线
图4-1. 儿茶酚紫指示剂在不同pH环境的CIE 1976(L*,a*,b*)参数(△E1、△E3)—pH曲线
图4-2. 儿茶酚紫指示剂在不同pH环境的CIE 1976(L*,a*,b*)参数(△E1-V、△E3-V)—pH曲线
图4-3. 儿茶酚紫指示剂在不同pH环境的CIE 1976(L*,a*,b*)参数(△E2、△E2φ)—pH曲线
图4-4. 儿茶酚紫指示剂在不同pH环境的CIE 1976(L*,a*,b*)参数(△E2α、△E2-V)—pH曲线
图5-1. 儿茶酚紫指示剂在不同pH环境的CIE 1976(L*,a*,b*)参数(σE)—pH曲线
图5-2. 儿茶酚紫指示剂在不同pH环境的CIE 1976(L*,a*,b*)参数(σL*)—pH曲线
图5-3. 儿茶酚紫指示剂在不同pH环境的CIE 1976(L*,a*,b*)参数(σa*)—pH曲线
图5-4. 儿茶酚紫指示剂在不同pH环境的CIE 1976(L*,a*,b*)参数(σb*)—pH曲线
图5-5. 儿茶酚紫指示剂在不同pH环境的CIE 1976(L*,a*,b*)参数(σC*)—pH曲线
图5-6. 儿茶酚紫指示剂在不同pH环境的CIE 1976(L*,a*,b*)参数(σH*)—pH曲线