Answer / satheesh kumar

Columns selection is main role for the separation of
compounds in method development.

1)Compounds solubility to be check
2)pKa of the compound

we know if the compound is acidic,fix pH nearer to pKa(+/-2)
Starts with ODS Column check the Compound RT,peak shape and
tailing criteria.
Generally HPLC Columns work between pH 2-8.If too acidic or
basic then columns packing will dissociate,
Some special columns are there to work in higher pH 8 to
namely X-Terra RP 18,Phenomenx Gemini C18.

Ensure what pH to be works for the concerned compound
select the columns accordingly

In method developement or in any analysis if we use small length column for analysis what happen then ? why ?

3 Answers  

---

In C8,C18....etc have 4&5 etc... microns Columns is there like that how to separate Chiral columns as per Micron size?

1 Answers  

---

What is difference b/w IR&NIR

1 Answers   Apotex,

---

What are the primary considerations in extractables and Leachables ?

0 Answers   Mylan,

---

How to fix the concentration for RS by HPLC

10 Answers   Intas, Reddy Labs,

---

what is mean by UOD?

2 Answers  

---

what is the defferance between the potency and working standard

1 Answers   Arbro Pharmaceuticals, Caplin Point, ECOlogics, Matrix, Orchid, Venus Remedies,

---

acceptance criteria for ph meter, hplc detector,pump,injector,oven when we calibrate.

3 Answers  

---

HOw do i calculate the number of theoretical plate on a HPLC chromatography

2 Answers   Laurus,

---

What is the formula for Tapdensity /

6 Answers   Dr Reddys, GR Intrachem,

---

What is the Defination of Tapdensity ?

4 Answers   Dr Reddys, R L Fine Chem,

---

One pH means how much volts and milivolts?

7 Answers   Dr Reddys,

---