Dear All,
I would like to measure the concentration of phosphorus element in a liquid sample by using HACH equipment. Since my samples are concentrated, I need to use micropipette to dilute the samples to a level that can be measured by the equipment ( required dilution factor ~1200 ). Since the required dilution factor is very high, it will affect my measurement significantly. Therefore, I would like to know how to calculate the error in the dilution factor ? also is there any practical tips to reduce this error to the minimum ?
Thanks in advance,
Calibrate the micropipette on use, using pure water, an analytical balance and a small plastic bottle with lid
Why not do two serial dilutions? For example (1 in 30) by (1 in 40) will yield a final dilution of 1 in 1200. The volume error in the two dilutions will more than likely be smaller than the measurement error of the equipment. You can check for that anyway with prepared standards which will probably require dilution to achieve the appropriate concentration.
Practical tip you asked for: scale up your dilution volumes. 40 µL in 50 ml is much easier to do than 1µl in 1.250 ml. Just consider how much influence will an extra 0.1µL droplet have on the 1 µL volume than the 40 µL volume?
If you use serial dilution I suggest that you do exactly likewise with your standards
I came across a manual written by Eppendorf which explains how to check the accuracy of micropipette . I attached it here in case someone needs this in the future.
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