蓚酸カルシウム結石におけるweddelliteのwhewelliteへの変化に関するX線学的検討

Abstract

室温にて保存された蓚酸カルシウム結石のX線粉末試料20例に対して, 4.9年～7.0年後に再度X線分析を施行し, 18例についてX線学的に求めたIwe/Iwe+Iwh+Iapの変化を検討した.尚, X線回折チャート上14.2～14.3°, 14.8～14.9°, 25, 8～25.9° (2θ)に現われる回折ピークの基線よりの高さ(mm)を測定し, それぞれIwe, Iwh, Iapとした.1) 3.5%以上のIwe/Iwe+Iwh+Iapの変化を有意とすると, 11例に蓚酸カルシウム2水化物の減少(3.5～13.9%)を認めた.この11例では, 1年間に平均1%の2水化物が1水化物に変化したことになる.2)結石中心部に存在する蓚酸カルシウム2水化物は, 結石表面の2水化物に比べて, 1水化物に変化しやすいと考えられる

A clay film was made of the stone powder and water drops on a slide glass and dried at 100 to 110 degrees C or at room temperature in the horizontal position for 20 calcium oxalate stones which had been received between April, 1978 and August 1980. Each clay film was scanned with an X-ray diffractometer using CuK alpha radiation, stored at room temperature in a wooden sample case and analysed again by X-ray five to seven years after the first X-ray analysis. Then the recent diffractograms of 20 powder samples were compared with the previous ones regarding the peak heights at 14.2 degrees, 14.8 degrees and 25.8 degrees (2 theta), which were considered representative of weddellite, whewellite and apatite contents and designated as Iwe, Iwh and Iap, respectively. Since there was a good correlation between Iwe/Iwe + Iwh + Iap and weddellite/weddellite + whewellite + apatite that was determined by thermogravimetry (Fig. 1), the transformation rate of weddellite to whewellite can be expressed as the change of Iwe/Iwe + Iwh + Iap. One sample Iwe/Iwe + Iwh + Iap of which decreased by 48% in seven years (Fig. 3) and another sample Iwe/Iwe + Iwh + Iap of which increased by 10% in five years (Table) were excluded from this study because the clay films of these samples might have been overheated or incompletely dried before the first X-ray analysis.(ABSTRACT TRUNCATED AT 250 WORDS)