Statistica Evaluation of Some Analytical Methods in the Hydrogeochemistry Laboratory of General Directorate of Mineral Research and Exploration

Yıl 1984, Cilt: 101-102 Sayı: 101-102, 12 - 19, 01.06.1984

Gülay Ataman Ataman Suheyla Tuncer Ersin Şen Muzaffer Sönmez Vedat Öztürk Mine Büyükkınacı

Öz

 Several analytical methods are being employed related to various research projects and routine works
on water samples in hydrogeochemistry laboratory of General Directorate of Mineral Research and Exploration. Some
statistical evaluations are necessary in order to obtain accurate results for the projects related. In order to control the
precision and accuracy of the chemical determinations in our laboratory, standard water samples have been requested from
EPA (Environmental Protection Agency, USA). The samples donated by EPA have been analyzed for 28 species using our
standard methods. Results of the determinations were compared with the true values supplied by EPA using «Studend's t
test». R values have been used to investigate the presence of systematic errors at 95 % an 99 % confidence levels. Accuracy
and precision of the analytical methods used have been statistically determined. No systematic error was observed for
43 results of the total of 54. Evaluation for systematic error could not be realized for 11 results. Relative percent errors
were found to be in the ranges at 0-10, 11-20, 21-50 and more than 50 for 33, 10, 6,5 results respectively. As a result
of this study, by applying the statistical tests for accuracy and precision, it has been determined that accurate results
are obtained in most of the methods, only two methods require further development. 

Anahtar Kelimeler

hydrogeochemistry, analytical, Student's test

Teşekkür

Authors would like to thank to Dr. A. Yıldırım for the facilities and the scientific support provided at every stage of this work; to the Environmental Protection Agency of U.S.A. for donating the standard water samples; to our skilled technician Aysel Kılıç for her hihg quality performance; and finally to the Computer Service Center of the General Directorate of Mineral Research and Exploration.

Kaynakça

• Laitinen, H.A., 1960, Chemical Analysis: Mc. Graw Hill Book Co., Toronto 611. Langley, R., 1971, Practical Statistics: Dover Publications Inc., USA 399.