不知道在实验室中工作的大家有没有遇到过这种情况:
想要移取某种溶液样品,但是发现移液器好像不准确需要进行校准。我不了解大家碰到这种情况是怎么做的,但是如果正好有人和我一样要求不是特别高,又怕麻烦,不想去计量单位校准的话,不妨可以采用我下面要讲的这个方法,也就是利用电子天平来校准移液器。那么我们具体该怎么做呢?
首先,我们需要准备一个已经校准过的电子天平,然后放一个小烧杯,去皮(即去掉装物品的篮子之类的容器的重量)。再用移液器移取一定量的蒸馏水(这里的一定量的蒸馏水需要我们自己先记好是移取了多少的量),然后移入小烧杯中称重。质量除以密度,就是蒸馏水的实际的体积了。当然在我们移取蒸馏水前最好先测下水温,因为不同温度蒸馏水的密度会有些不同,具体不同温度蒸馏水的密度见下表所示。
蒸馏水在不同温度下密度 | |||||||||||
温度 |
0.0 |
0.1 |
0.2 |
0.3 |
0.4 |
0.5 |
0.6 |
0.7 |
0.8 |
0.9 |
差数X10 |
5 |
0.9999919 |
0.9999902 |
0.9999883 |
0.9999842 |
0.9999842 |
0.9999819 |
0.9999795 |
0.9999769 |
0.9999741 |
0.9999712 |
1 |
6 |
0.9999681 |
0.9999649 |
0.9999616 |
0.9999581 |
0.9999544 |
0.9999506 |
0.9999467 |
0.9999426 |
0.9999384 |
0.999934 |
1 |
7 |
0.9999295 |
0.9999248 |
0.99992 |
0.999915 |
0.9999099 |
0.9999046 |
0.9998992 |
0.9998936 |
0.9998879 |
0.9998821 |
2 |
8 |
0.9998762 |
0.9998701 |
0.9998638 |
0.9998574 |
0.9998509 |
0.9998442 |
0.9998374 |
0.9998305 |
0.9998234 |
0.9998162 |
3 |
9 |
0.9998088 |
0.9998013 |
0.9997936 |
0.9997859 |
0.999778 |
0.9997699 |
0.9997617 |
0.9997534 |
0.999745 |
0.9997364 |
5 |
10 |
0.9997277 |
0.9997189 |
0.9997099 |
0.9997008 |
0.9996915 |
0.999682 |
0.9996724 |
0.9996627 |
0.9996529 |
0.9996428 |
6 |
11 |
0.9996328 |
0.9996225 |
0.9996121 |
0.9996017 |
0.9995911 |
0.9995803 |
0.9995694 |
0.9995585 |
0.9995473 |
0.9995361 |
2 |
12 |
0.9995247 |
0.9995132 |
0.9995016 |
0.9994898 |
0.999478 |
0.999466 |
0.9994538 |
0.9994415 |
0.9994291 |
0.9994166 |
0 |
13 |
0.999404 |
0.9993913 |
0.9993784 |
0.9993655 |
0.9993524 |
0.9993391 |
0.9993258 |
0.9993123 |
0.9992987 |
0.999285 |
1 |
14 |
0.9992712 |
0.9992572 |
0.9992432 |
0.999229 |
0.9992147 |
0.9992003 |
0.9991858 |
0.9991711 |
0.9991564 |
0.9991415 |
1 |
15 |
0.9991265 |
0.9991113 |
0.9990961 |
0.9990608 |
0.9990653 |
0.9990497 |
0.999034 |
0.9990182 |
0.9990023 |
0.9989862 |
2 |
16 |
0.9989701 |
0.9989538 |
0.9989374 |
0.9989209 |
0.9989043 |
0.9988876 |
0.9988707 |
0.9988538 |
0.9988367 |
0.9988175 |
6 |
17 |
0.9988022 |
0.9987849 |
0.9987673 |
0.9987497 |
0.9987319 |
0.9987141 |
0.9986961 |
0.9986781 |
0.9986599 |
0.9986416 |
9 |
18 |
0.9986232 |
0.9986046 |
0.9985861 |
0.9985673 |
0.9985485 |
0.9985295 |
0.9985105 |
0.9984913 |
0.998472 |
0.9984326 |
14 |
19 |
0.9984331 |
0.9984136 |
0.9983938 |
0.998374 |
0.9983541 |
0.9983341 |
0.998314 |
0.9982937 |
0.9982733 |
0.9982529 |
18 |
20 |
0.9982323 |
0.9982117 |
0.9981909 |
0.9981701 |
0.998149 |
0.998128 |
0.9981068 |
0.9981695 |
0.9980641 |
0.9980426 |
22 |
21 |
0.998021 |
0.9979993 |
0.9979775 |
0.9979556 |
0.9979335 |
0.9979114 |
0.9978892 |
0.9978869 |
0.9978444 |
0.9973219 |
25 |
22 |
0.9977993 |
0.9977765 |
0.9977537 |
0.9977308 |
0.9977077 |
0.9976846 |
0.9976613 |
0.997638 |
0.9976145 |
0.9975918 |
27 |
23 |
0.9975674 |
0.9975437 |
0.9975198 |
0.9974959 |
0.9974718 |
0.9974477 |
0.9974435 |
0.9973991 |
0.9973717 |
0.9973502 |
29 |
24 |
0.9973256 |
0.9973009 |
0.997276 |
0.9972511 |
0.9972261 |
0.997201 |
0.9971758 |
0.9971505 |
0.997125 |
0.9970995 |
30 |
25 |
0.9970739 |
0.9970432 |
0.9970225 |
0.9969966 |
0.9969706 |
0.9969445 |
0.9969184 |
0.9968921 |
0.9963657 |
0.9968393 |
31 |
26 |
0.9968128 |
0.9967861 |
0.9967594 |
0.9967326 |
0.9967057 |
0.9966726 |
0.9966515 |
0.9966243 |
0.996597 |
0.9965696 |
30 |
27 |
0.9965241 |
0.9965146 |
0.9964869 |
0.9964591 |
0.9964313 |
0.9964033 |
0.9963753 |
0.9963472 |
0.996319 |
0.9962907 |
29 |
28 |
0.9962623 |
0.9962338 |
0.9962052 |
0.9961766 |
0.9961478 |
0.996119 |
0.9961901 |
0.996061 |
0.9960319 |
0.9960027 |
28 |
29 |
0.9959735 |
0.995944 |
0.9959146 |
0.995885 |
0.9958554 |
0.9950257 |
0.9957958 |
0.9957659 |
0.9957359 |
0.9957059 |
25 |
30 |
0.9956756 |
0.9956454 |
0.9956151 |
0.9955846 |
0.9955541 |
0.9955235 |
0.9954928 |
0.995462 |
0.9954312 |
0.9954002 |
23 |
31 |
0.9953692 |
0.995338 |
0.9953068 |
0.9952755 |
0.9952442 |
0.9952127 |
0.9951812 |
0.9951495 |
0.9951178 |
0.9950861 |
20 |
32 |
0.9950542 |
0.9950222 |
0.9949901 |
0.994958 |
0.9959258 |
0.9948935 |
0.9948612 |
0.9948286 |
0.9947961 |
0.9947635 |
19 |
33 |
0.9947308 |
0.994698 |
0.9946651 |
0.9946321 |
0.9945991 |
0.994566 |
0.9945328 |
0.9944995 |
0.9944661 |
0.9944327 |
17 |
34 |
0.9943991 |
0.9943655 |
0.9943319 |
0.9942981 |
0.9942643 |
0.9942303 |
0.9941963 |
0.9941622 |
0.994128 |
0.9940938 |
16 |
35 |
0.9940594 |
0.9940251 |
0.9949906 |
0.994956 |
0.9949214 |
0.9948867 |
0.9948518 |
0.994817 |
0.994782 |
0.994747 |
16 |