Trona is one of the natural forms of sodium carbonate minerals. It is well known as «sesque carbonate», «urao» or «trona» in the chemical literature, and the chemical formula of the compound is [Na2CO3 .NaHCO3 .2H2O]. The aim of this work is to adopt the standard methods for the analysis of trona samples, considering the interferences arising from silicates and other minerals found together with trona samples. In order to reduce the experimental errors, the analyses used for the determination of trona samples have been revised. The experimental results using potentiometric titration, AgNO3 external indicator and BaCl2 titration methods have been compared to theoretical results using statistical evaluations. 95% confidence level, which is commonly used by analytical chemists, was employed as the basis of evaluation, R values, Student's t calculated at 95% confidence level of 7 trona samples from Beypazarı, Student's t tabulated for the percentages of Na2CO3 , were found to be 0.008 in BaCl2 method, 3.25 for AgNO3 external indicator method and 3.26 for potentiometric method; for the percentages of NaHCO3 the same values are 0.59 for BaCl2 method, 2.83 for AgNO3 external indicator method and 3.59 for potentiometric method. Systematic error is indicated when R> 1. In addition to quantitative analysis of trona samples, qualitative XRD analyses have been routinely performed for each sample and the results were found to be in good agreement.