COMPARATIVE STUDY BETWEEN ACID-BASE TITRATION AND FLAME PHOTOMETRY FOR DETERMINATION OF Li2CO3 WITH AS RAW MATERIAL AND PRODUCT

TF05

Zumira Aparecida Carneiro(1),  Mariella Buso Pereira(2),  Natal Junio Pires(3)

1 – Universidade de São Paulo – Ribeirão Preto  2 – Universidade de Uberaba/MG  3 – Centro Federal de Formação Tecnológica de Minas Gerais – CEFET-MG – Campus Araxá

The lithium carbonate (Li₂CO₃) is often referred to as drug "antimaniac" but in many parts of the world is regarded as a drug "stabilizing of the metal condition" because of its action in the primary prevention of the mood swings in patients with bipolar affective disorder (manic-depressive). Commercially can be found with the name of CARBOLITIUM^® (300 mg) or CARBOLITIM CR^® (450 mg), the latter being prolonged action.For quality control of Li₂CO₃ as raw material, as well as finished product, the United States Pharmacopeia (USP) recommended the use of acid-base titration. However, this procedure spends large amounts of reagents and is more subject to error.In this sense, it is necessary to seek simple techniques that allow smaller generation of waste and decrease the amount of material and spent determinations that are as effective as the methodologies that already exist. Under these conditions, we propose to evaluate the use of a flame photometry as alternative technique for determining the lithium carbonate in raw material, as well as finished product.For comparison performed all analyses (n = 4) using the official method recommended (USP) and then comparing the results obtained with the method proposed. For this, use the Student's t test. For a significance level of 5% and 3 degrees of freedom, the critical value (tabled) from t is 2.35. Obtained a value of t_calculated equal to 2.08 for raw material. For the finished product this value was 0.95. Thus, in both situations have to t_calculated < t_tabled, so that the results using both methods are statistically equal. The main advantages, the photometry of flame generates little amount of waste, is faster and simpler than the method recommended. So it appears that it is feasible the use of a flame photometry for determination of Li₂CO₃ in both types of samples.