front 1 1. define the problem | back 1 must know what information is needed, by whom, for what purpose, and what type of sample is to be analyzed |
front 2 2. select a method | back 2 identify the sample type, size of sample, its cost, etc. |
front 3 3. obtain a representative sample | back 3 get the sample type and its sampling statistics |
front 4 4. prepare the sample for analysis | back 4 any preparations such as chemical separation and/or concentration for the sample |
front 5 5. prepare any necessary chemical separations | back 5 such as distillation, precipitation, extraction etc. |
front 6 6. perform the measurement | back 6 calibrate, validate, and replicate |
front 7 7. calculate the results and report | back 7 using statistical analysis, the results are interpreted and evaluated carefully |
front 8 contamination, loss, decomposition, matrix change | back 8 certain precautions should be taken in handling and storing samples to prevent or minimize |
front 9 the container, atmosphere, heat, temperature, or light | back 9 prevent contamination or alteration of the sample by |
front 10 method of standard additions | back 10 calibration technique wherein if there is any interference or spike in the sample, a known amount of substance helps compensate it |
front 11 internal standard calibration | back 11 adding a known quantity of a substance that behaves the same way as the analyte, but is not the analyte or present in the sample naturally. |
front 12 two validations of a method | back 12 random and systematic |
front 13 random | back 13 measurement has some imprecision associated with it, which results in random distribution of results, for example, a Gaussian distribution |
front 14 systematic | back 14 one that biases a result consistently in one direction (analytical balance is skewed high or low) |
front 15 analyze | back 15 a sample is analyzed for all its constituents and the substance measured are the analytes |
front 16 determination | back 16 process of measuring the analyte |