Primary , secondary , tertiary amines can be separated by the following except :

Options

A. Fractional distillation
B. Fractional method ysubg duetgtk oxalate
C. Hinsberg' s method using ` C_6 H-5 SOCl`
D. Selective crtystallisation

Explanation

To solve the question regarding the separation of primary, secondary, and tertiary amines, we need to analyze the methods provided and determine which one cannot be used for their separation.

### Step-by-Step Solution:

1. **Understanding Amines**:
- Primary amines have one alkyl group attached to the nitrogen.
- Secondary amines have two alkyl groups attached to the nitrogen.
- Tertiary amines have three alkyl groups attached to the nitrogen.

2. **Methods of Separation**:
- The question lists several methods for separating these amines. We need to evaluate each method to see if it can effectively separate primary, secondary, and tertiary amines.

3. **Fractional Distillation**:
- This method utilizes the differences in boiling points of the amines. Since primary, secondary, and tertiary amines have different boiling points, fractional distillation can effectively separate them.
- **Conclusion**: Fractional distillation can be used.

4. **Hinsberg Method**:
- The Hinsberg method involves treating amines with benzene sulfonyl chloride (C6H5SO2Cl).
- Primary amines form soluble sulfonamides, secondary amines form insoluble sulfonamides, and tertiary amines do not react. This allows for the separation of the three types of amines.
- **Conclusion**: The Hinsberg method can be used.

5. **Selective Crystallization**:
- Selective crystallization relies on the different solubilities of compounds in a solvent. However, primary, secondary, and tertiary amines may not have sufficiently different solubilities to allow for effective separation using this method.
- **Conclusion**: Selective crystallization cannot be used effectively for separating these amines.

6. **Final Answer**:
- The method that cannot be used to separate primary, secondary, and tertiary amines is **selective crystallization**.

### Summary:
The correct answer to the question is that primary, secondary, and tertiary amines can be separated by all methods listed except **selective crystallization**.