Answer Posted / habib dawar

primary standard are those which have highest stability,purity,stability and doesn't fluctuate in variable environmental condition.

while secondary standard are those which have impurity(<96-98%),unstable and fluctuate with environmental condition(like sensitive to moist,light,)

using gradient pressure in gas chromatography are not ?using gradient pressure why

3332

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What is the diference between residual solvents and organic volatile matter

1961

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what is the importance of peak purity in HPLC and how we can calculate through manul(not software)?

4419

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for inorganic molecules require to do RS, Assay and disso?

668

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How they found 1mL of K.F reagent is equivalent to 5mg of water and if we change the composition of K.F reagent, is it can neutralize more amount of water?

1721

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What is the difference between chromatographic purity and related substances?

1295

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if content uniformity passing but dissolution varrying then what is next step?

814

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For limit test of heavy metals in BP, Method C require that the substance is ignited at a temperature not exceeding 800 °C. Why confines such the temperature?

4001

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

2600

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what is classification of elemental impurities? what is risk assement in elemental impurities?

705

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iam usig ph buffers merk. manually how to prepare ?

2220

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2. Two grams of Benzoic acid are dissolved in 200 ml of water and extracted with 200 ml of diethyl ether. The distribution coefficient of benzoic acid is 100, and its dissociation constant is 6.5 10-5. Calculate the distribution ratio (D) of benzoic acid at pH 2, 5, and 6. 3. Calculate D at pH 2 to 10 (1 unit apart) in the above problem, and plot D versus pH.

2170

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Tell me about analytical method validation in QC

6123

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HI,I CLEARED BOB CLERK EXAM. MY INTERVIEW WILL BE ON 9TH OCTOBER,2010.PLEASE SEND ME INTERVIEW QUESTIONS AND ANSWERS. THANK YOU.

2186

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What is similarity factor and its use in api strength?

1245

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