Selected examples of recommended storage conditions.

Sample storage

Often there is no choice but to store samples. It is a requirement of many experiments especially where the analysis cannot be carried out straight away. Unfortunately, if you store the sample incorrectly it will come out of storage different to how it was when it went it.

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A blank look at… blanks

There are many definitions of a “blank”. The official definitions often say something like: a sample that includes everything that will be present in the samples of interest except the analyte of interest. However, this is not what the word blank is always used to refer to.

Electrical conductivity of some common solutions

Conductivity of a solution

Conductivity of a solution appears a very simple measurement. Probe goes in, number comes out. Simple? While a number certainly comes out whether that number has any meaning requires slightly more careful handling.

Exaggerated representations of the z and t distributions

Uncertainty

To measure the uncertainty associated with a set of results you need to repeat measurements.

The difference between accuracy and precision.

Accuracy and precision

Accuracy: how close to the “true” value you are (e.g. how close to your true weight your bathroom scales weigh you to).

Rejecting data (Outliers)

Your data may not fit your pet idea, or even the generally accepted scientific theory, but that does not they are wrong.

TIC/TOC – measuring carbon

Meausring the carbon content of soils, sediments and rocks is a key measurement in geochemistry and other related sciences.

BET surface area

BET is one of the few methods available for surface area measurement and has the advantage of being able to give a measure of porosity.

Calibration standard preparation using volumetric flasks.

Preparation of calibration standards

Calibration standards are key to the analytical process as they are used to create the calibration curve. Better the calibration standards the better calibration curves and so the better the results.