What is in plasma other than water?

The short answer is: proteins, nutrients, electrolytes, hormones, vitamins, minerals, and waste products.

Long answer:

1. Plasma proteins such as albumin, fibrinogen, gamma globulin, prothrombin

2. Nutrients like glucose, fatty acids, cholesterol, and amino acids

3. Electrolytes, including sodium chloride and potassium chloride

4. Hormones, vitamins, enzymes

5. Metabolic waste