Is it possible by a blood test or a urine test to determine if I have a dopamine deficiency?

Sure it is.... There are plenty of people who'd love to tell you TO THE NANOGRAM how much dopamine you HAVE in your blood or urine, what you're deficiency is, & how much you need to become normal. BUT- how replacement will impact you's a TOTALLY DIFFERENT QUESTION. I wouldn't spend money getting such tests. They're of no value to the clinician who knows how to treat dopamine deficiency diseases.
Not aware of any. I am not aware of an available blood or urine test for dopamine deficiency. Please explain why you seek this and perhaps there is another way to address the problem.