Minimizing and rectification of common analytical errors in laboratory.

Hai viewers........

Sorry for taking long gap to my blog.

But Today I come up with new and very important topic for all analysts and scientists....

 "Minimizing and rectification of common analytical errors"

Before going into the hot topic, I want give definitions of some common terms.

True value : A value compatible with the definition of a given particular quantity.

Error : An error is a " Deviation from a true value"

Mistake : Mistake is an error caused by a fault. The fault being a misjudgement, carelessness, forgetfullness etc...

     "errors occurs... Mistakes are made....."

"Machines have errors.... Humans makes mistakes.."

So from the above quotes, what can be concluded..?

Errors may occur mechanically... but mistakes were done by humans.

Machine or instruments may give errors, if a person makes a mistakes.

" Errors cannot be rectified but can be minimized.....

                          Mistakes can 100% rectified, because it is a human errors...."

                     "Errors can be minimized by rectifying human mistakes"

Why Acceptance limit or specification limit come into picture..?

As I already told,  errors cannot be rectified but it can be minimized. So definitely there should be certain limit for the analytical result.

So there a possibility to rectify mistakes which is in the hand of Analyst or Scientist.

" A best analyst or scientist cannot commit mistakes"

One analyst asked me some questions as follows. 

                    

                       "Yes.. I want to be one of the best analyst. But How..?"

My Answer:  

                       First of all, I will tell why mistakes will happen..

                             1) The person may have lack of experience.
                             2) The person may have lack of knowledge.
                             3) The person may lack of attitude, care ( means having laziness), interest, problem solving skills, self confidence, self thinking to settle an issue(plan), etc...(human errors).
                             4) The person may have lack of self checking.

So If you overcome all above points, you will become a best analyst or scientist.

 How to overcome..? How to become best best analyst.?

Answer:        A) know what you are going to do.( pre-plan).
                        B) Read the procedure carefully (Care).
                        C) Learn technique behind the test or process (knowledge).
                        D) put interest on analysis or work.
                        E) Self check each step you are doing.
                        F) Ensure each step whether you are doing correctly or not.
                        G) Build confidence on your work by ensuring above all.
                        H) Learn tips and tricks from experienced people.(Pipetting, Sample preparation & trouble shooting etc...).

Generally from where errors may occur..? (Sources of errors).

Answer: 
                Sources of errors:

                  a) Input Data: Standard & its potency used (wrong standard or wrong potency).
                                             Calibration values (example: KF factor)
                                             Physical constants etc....

                  b) Quantity measured: Titre value, volumes, Weights etc....
  
                  c) Instruments used: Example: If UV-VIS spectrometer is not suitable for assay analysis, we have to go for HPLC analysis for better accuracy and repeatability.( So, UV not suitable, HPLC suitable). Instruments used are not calibrated properly.

                  d) Observer fallability: Reading errors (example: analyst taken wrong STP or misunderstood wrongly.)

                  e) Environment: Method conditions, Temperature, Humidity etc....

                   f)  Theory assumed: Calculations, Approximations etc...


       What types of errors may occur..? (Types of errors).    

Answer: 
                      Random Error: errors that vary in an unpredictable manner in replicated measurements.

                      Systematic Error: the results of analytical measurements to one side, to higher or lower values which lead to false results.

                      Trend Error: A data set shows a trend when the chronologically ordered values move steadily downwards or upwards.

                      Gross Error: Gross errors result from human mistakes, or have their origins in

instrumental or computational errors. Frequently, they are easy to recognize and the

origins must be eliminated.

Statistical Evaluations to understand extent of errors:

      

Mean, Standard deviation, Variance, %RSD, Coefficient of variance, etc...... are some of the statistical evaluations for estimating the extent of error to the true value.

Parameters to Control Errors:

There are many parameters for control the Errors.

Examples : Precision, Linearity, Accuracy,Specificity etc…..

Instruments: Calibrations, Preventive maintanance, performance verification etc….

Methods: validations, Verifications, system suitability etc…,

Documents: Review, quality assurance, etc…,

Analysts: Trainings, Practise etc….

Why to control Errors : 

Answer is : If we control the errors it directly controls the quality of the product.

Thanks

V.Suresh