Analytical Chemistry Interview Questions
Questions Answers Views Company eMail

1.What is the difference between method validation and method verification 2.Which guidelines proposed to method transfer

Granules,

348

My question about gas chromatography sulfur chemiluminsecence detector. I test unknown sample gas by GC-SCD (calibrated ) and the result of *H2S is 279 PPM , *but when I test the same sample with the GC-TCD (calibrated ) the value of *H2S is 2500 PPM . I'd like to inform you that both GCs are calibrated and have very good operation conditions with stable parameters . the question is if the sample gas with higher H2S over detection limits of SCD detector (1000 ppm). why the result it 279 ppm Best regards

304

what is peak purity and its formula

322




Why potassium dichromate is used in calibration of uv?

457

Why sometime potassium ortho phosphate mix with acetone use for sample preparation for hplc

346

What is difference between known and unknown impurities

Sun Pharma,

252

What is the difference between known and unknown impurities?

1 559

why we are using hexane in calibration of number of drop per mL

318




Why to use propyl paraben in HPLC gradient calibration

Glenmark,

1069

Why potassium dichromate was using in Uv calibration?

1 792

%lod always grater than %water content for same product??

1 507

We use Potassium Dichromate solution for the calibration of UV-Visible Spectrophotometer in UV region. My question is to calibrate visible region which solution could be used in photometric accuracy

336

How to define samples weight in moisture content

1 340

What is AV value in test uniformity content ,describe calculation

Lupin,

1 556

Why perchloric acid used for potentiometric titration

1400


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Un-Answered Questions { Analytical Chemistry }

what is peak purity and its formula

322


For standardization of volumetric solutions, acceptance limit for concentration is considered as 10% of nominal concentration and %RSD as NMT 0.2% (for appropriate no. of replicates). But , if %RSD has not met, what should be further action?

211




1135


Qc interview questions

456


How can we confirm the HPLC column is end-capped or not? Is it possible to identify by physical appearance?

1937






What is the difference between purge septum flow and column flow in gas chromatography?

873


what is impurity profile. how to interpret this impurity profile to a drug product or drug substance.

1222


Why Ethanol is Used for Standardization of GC Head space?

2721


what is %labelled amount in content uniformity of dosage unit and its calculation?

3711


please explian me about area normalisation method,diluted standard method,impurity vs impurity and which one has to be selected in method development

415


What is the formula to determine the concentration of M of a solution given the % transmittance? Use %T = 43.7 as an example.

1407


when we talk about change in entropy we consider total entropy means of surround +entropy of system but when we talk about change in Gibss free energy we consider entropy of system.explain with reason.

855


Home heating oil or furnace oil what is made from? Can (base oil plus diesel/kerosen) = home heating oil?

958


some product having water content method with pyridine and ethylene glycol mixture instead of methanol? how they are selecting and methanol is not suitable solvent how ?

1243


calibrtion procedue of LC-MS

1351