Environmental Method to Determine Dopamine and Ascorbic Acid Simultaneously via Derivative Spectrophotometry

Table 2

Determination of dopamine and ascorbic acid in synthetic mixtures and real samples by first and second derivative spectrophotometry.

Sample number	Recovery (%)
	DA		AA
	𝐷2^251	𝐷2^281	𝐷1^259	𝐷2^275	𝐷2^297
1	100	100	100	104	102
2	98	99	100	98	100
3	99	100	100	101	101
4	99	100	—	—	—
5	—	—	100	98	99
Urine 1	100	99	99	98	98
Urine 2	99	99	99	100	99

Sample 1: 1.89 mg L⁻¹ of DA and 3.52 mg L⁻¹ of AA, Sample 2: 3.78 mg L⁻¹ of DA and 1.76 mg L⁻¹ of AA, Sample 3: 1.89 mg L⁻¹ of DA and 1.76 mg L⁻¹ of AA, Sample 4: injection content 200 mg/5 mL, Sample 5: tablet content 100 mg. Average of three determinations based on the drug label. Urine 1: 2.0 mg L⁻¹ of DA and 2.16 mg L⁻¹ of AA were added; Urine 2: 1.95 mg L⁻¹ of DA and 2.06 mg L⁻¹ of AA were added.