結石分類と成分分析法

Study of urinary calculi by means of x-ray diffraction and infrared spectroscopy

尿路結石に含まれるヒドロキシアパタイトとカーボネートアパタイトは結晶度が極めて低く，X線回折法では見逃されやすい．赤外分光分析ではカーボネートアパタイトはリン酸カルシウムと炭酸カルシウムの混合と判定されることが多い．尿路結石の成分分析では赤外分光分析とX線回折法の併用が望ましいが，カーボネートアパタイトないしヒドロキシアパタイトからなる大結石では，少量のリン酸マグネシウムアンモニウムの検出は困難なことがある．

The presence of apatite (hydroxylapatite or carbonate apatite) in urinary calculi may be overlooked by x-ray diffraction because of its lower crystallinity.　Although infrared spectroscopy is much more sensitive for detecting apatite than x-ray diffraction, carbonate apatite may be confused with calcium carbonate and hydroxylapatite.　Although the composition of urinary calculi is best determined by x-ray diffraction and infrared spectroscopy, it may be difficult to find a small amount of magnesium ammonium phosphate in large calculi composed mainly of apatite.