Answer Posted / venkata padmanabheswara rao

Primary Standard:
A substance that is widely acknowledged to have the
appropriate characteristics within a specified context and
whose value is accepted without requiring comparison to
another substance, this substance should be obtained from
official recognized sources.

Secondary
A substance of established quality and purity as shown by
comparison to a Primary standard used as a Secondary
standard for routine laboratory analysis. It serves as a
substitute for its corresponding Primary standard.

what is mean by nitrosamine impurities?

1069

---

Colorimtry

1660

---

Which type of column should i use to check the purity of high molecular weight protein using HPLC reverse phase column chromatography? Hi everyone. I wanna to check the purity of high molecular weight protein (collagen) with MW of ~130 kDa using a HPLC. I know C18

1917

---

How to determine the EDTA content by potentiometry titration in Ceftriaxine sodium

2546

---

how require to set assay concentration for standard and sample?

923

---

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.

2043

---

In performance Check of GC Why Hexadecane Peak is Considered 

3045

---

How to calculate coreletion coefficient

1714

---

why lactose has less charges when packed in steel containers when compared with packing of lactose in polyamide material?

2299

---

How to choose the which salt is suitable for mobilephase

3250

---

why require to add enzymes in capsules dissolution only? is it require to tablet also?

679

---

How to calibration of the uv spectroscopy and its test?

1196

---

what is the principle involved in turbidometry and nephelometry ?

4159

---

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

760

---

Why six unit used for precision?

1352

---