In HPLC calibration, caffeine is used as primary standard for wave length calibration due to caffeine is having dual maxima at 273 & 205 nm and one minima at 245 nm. Any body can give reference of these details from any pharmacopeia (with chapter no.) or any other authentic guideline?

1986

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How to check the integrity of Sieve, Screen, FBD Bag?

8723

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could negative ions be produced by bombardment process in mass spectrometry?

1794

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A ha tc is actual defination of retention time?

1629

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Does domestic/household used kerosene oil which is available in blue color (In India) can change its color over the due course of time say 8-10 years if keeping in plastic bottle? If so, in which color it will be turned to change, yellow or transparent or any other color. Please provide me the reply with strong technical approach. Since it has been asked during an interview. Please reply fast. I will be thankful to you if anyone can provide the supporting journals/write-ups/reference to favour of response.

1435

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Available paper in exam gnfc

1359

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why ph is not more than 14?

1529

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

1865

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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

1613

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Why potassium dichromate is used in calibration of uv?

2004

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

1481

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What is the difference between Assay and Purity?

1546

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Can we quantify bound water by KF titrator ?

1414

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

1748

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Why we have to add 200mg Na2CO3 in preparation of 0.1N sodium thiosulfate solution?

1584

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