Our pilot study indicates that Raman spectroscopy is a valid and reliable technique for determining urinary stone composition. Thus, we propose that the development of a compact and portable system based on Raman spectroscopy for immediate, postoperative stone analysis could represent an invaluable tool for the metaphylaxis of urolithiasis.

Lesch-Nyhan syndrome is a disorder caused by congenital absence of the enzyme hypoxanthineguanine phosphoribosyltransferase and an increase of the enzyme activity of adenine phosphoribosyltransferase. Treatment should be adjusted to patient's age and weight. An adapt treatment with allopurinol and optimal fluid intake reduce the risk of uric acid or xanthine lithiasis. Laboratory monitoring includes testings for serum concentration and urinary excretion of uric acid, xanthine and hypoxanthine. Sole a normal concentration of uric acid is not sufficient for therapy control. Assessment of the urine sediment by microscopy or infrared spectroscopy will enable early detection of uric acid or xanthine lithiasis.

For five samples of our 5th international ring test for the quality control of methods of urinary calculus analysis we received 46 results from 19 countries obtained by means often different methods. The mean standard of quality (SQ) for all participants with quantitative methods is 2.11. Most laboratories employed X-ray diffraction (n = 21; SQ = 2.09) for quantitative calculus analysis. The mean deviation (▵x) per component from the ideal composition is fortunately low – about 0.10 molar parts for all participants, 0.06 molar parts for X-ray and infrared spectroscopy technique together. From the aspect of accuracy, the physical methods of analysis, X-ray diffraction and IR spectrophotometry, are clearly superior to all other analytical techniques.

For five test samples of the fourth International Ring Test to check the quality of methods for urinary calculus analysis, 45 findings obtained by 10 different methods were sent from 16 countries. The mean deviation of 0.11 molecular parts per component for all five samples is considerably low. The average standard SQ for all participants is 2.44. It falls off from X-ray diffraction via IR down to other quantitative methods. Advantages and disadvantages of X-ray diffraction and IR-spectroscopic analyses are discussed. Analysis of urinary calculi according to centralized, methodically uniform standards offers advantages in analytical quality.

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