These free B.Pharm notes on errors in pharmaceutical analysis cover chapter 2 of Pharmaceutical Inorganic and Analytical Chemistry (BP106T), a first-semester subject. Read the key points below, then study the complete chapter PDF. You can browse every chapter in the Pharmaceutical Inorganic and Analytical Chemistry category.
Table of Contents
Read the following document for full information
Overview of errors in pharmaceutical analysis
These notes explain what an error is and how absolute error is expressed. They then cover the three types of errors: determinate or systematic errors, indeterminate or random errors and gross errors. The final part lists methods of minimising errors, including blank, control and parallel determinations, calibration, independent methods, standard addition, internal standard, amplification methods and isotope dilution analysis.
Key points on errors in pharmaceutical analysis
- Absolute error is the difference between the experimental value and the true value, and it may be positive or negative and is often given as a percentage.
- Determinate or systematic errors have identifiable causes, such as personal, instrumental, reagent and method errors, so they can be removed once their origin is found.
- Indeterminate or random errors come from unpredictable changes in conditions, cannot be removed by calibration and are reduced by more experiments and statistics.
- A blank determination is done under identical conditions without the sample, and the correct titrant volume equals V(sample) minus V(blank).
- In standard addition or spiking, known amounts of standard are added to aliquots of sample, and the unknown concentration equals b/m from the plotted line.
Relevance to pharmacy practice
Every assay and limit test a pharmacist performs is only as reliable as its control of errors, and a large error can have serious results for patients. Learning to recognise error types and use blanks, controls and calibration builds accurate and precise results in quality control.
Every chapter in this subject builds on the one before it, so do not skip topics that look simple. Definitions, principles, procedures and examples are the parts that examiners return to most often, and a clear understanding here will also make later subjects easier to follow in the coming semesters.
Frequently asked questions on errors in pharmaceutical analysis
What are the three types of errors in analysis?
The three types are determinate or systematic errors with identifiable causes, indeterminate or random errors from unpredictable changes in conditions, and gross errors or blunders caused by human mistakes.
What is a blank determination?
A blank determination is the experiment done under identical conditions without the test sample, which reveals errors from impurities in reagents, solvents or indicator.
How should gross errors be handled?
Gross errors are human mistakes such as sample contamination, reading errors or typing mistakes, so the data should be discarded and the whole experiment repeated.
Quick revision checklist
Use this self-test after reading the chapter on errors in pharmaceutical analysis. If you can do all of the following without looking at your notes, you are ready for the exam.
- I can explain: the meaning of absolute error
- I can explain: determinate, random and gross errors
- I can explain: sources of systematic errors with examples
- I can explain: blank, control and parallel determinations
- I can explain: standard addition and internal standard methods
Study and exam tips
Start by reading the chapter once for the overall idea, then revise errors in pharmaceutical analysis using headings, definitions, principles, reactions and examples. Short-answer questions in the university exam usually ask for definitions, principles, procedures, reactions and uses, so write these in your own words and practise the equations, tables and flow charts that the chapter has.
For wider reading, standard books and open resources such as the NCBI Bookshelf help you confirm terms and see more examples. Revise errors in pharmaceutical analysis again a day later and again a week later, because spaced revision improves long-term memory.
This page is part of the Pharmaceutical Inorganic and Analytical Chemistry series for first-semester B.Pharm students on B.Pharm Guru, where every chapter has a short summary and a full PDF. Bookmark this page and share it with classmates who are preparing for the same exam.
Related notes: 4. IMPURITIES, 5. LIMIT TESTS: CHLORIDE, SULPHATE, IRON, ARSENIC AND LEAD.
Next: 3. ACCURACY, PRECISION AND SIGNIFICANT FIGURES. Back to the Pharmaceutical Inorganic and Analytical Chemistry category.
