Analytical Chemistry Cheat Sheet

Yam Kah Meng CM2142 Analytical Chemistry 1.

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Precision vs. Accuracy  Precision is the measure of closeness of results to others obtained in the exact same way and is affected by random errors.  Accuracy is the measure of closeness of a measure value to the true value and is affected by systematic errors. Repeatability vs. Reproducibility  Repeatability: ability to obtain results with within-run precision under same conditions.  Reproducibility: ability to obtain results with between-run precision under different conditions. Significance Tests Significance Tests z - test t - test Pooled t test Paired t test Fisher F test Dixon Q test ANOVA

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Usage Compares large sample to standard Compares small sample to standard Compares two data sets by their means Compares two data sets by the mean of their differences Compares variances of two data sets Compares outlier to the rest of the data Compares more than two data sets by their means

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Type I Error vs. Type II Error  Type I error is when H0 is rejected even though it is true and has a higher chance of occurring with lower CL and higher α.  Type II error is when H0 is retained even though it is false andhas a higher chance of occurring with higher CL and lower α.

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Classification of Analysis Based on sample size  Ultramicro: 0.1 g Based on analyte level  Ultratrace: