McLean J R, Mortimer A J
Bureau of Radiation and Medical Devices, Health and Welfare Canada, Ottawa, Canada.
Ultrasound Med Biol. 1988;14(1):59-64. doi: 10.1016/0301-5629(88)90164-0.
A simple and sensitive method is described for measuring the number of hydroxyl radicals (.OH) produced in aqueous solution by high intensity ultrasound (US). The method is based on the conversion of nonfluorescent terephthalic acid (TA) to highly fluorescent hydroxyterephthalate (HTA). The spectrofluorimeter is calibrated by use of a TA solution which has been exposed to a reference dose of cobalt-60. This allows fluorescence readings produced by ultrasound to be read directly in equivalent centiGrays (cGy). The limit of detection for OH is about 1.3 X 10(-9) M (equivalent to an exposure of about 0.5 cGy of cobalt-60). The threshold for transient cavitation (TC) in an air-saturated aqueous solution was found at 0.7 watts per cm2. Cavitation was consistently produced when TA was exposed in a soft vinyl chamber and only when the chamber was being rotated about an axis which was perpendicular to the US beam. The use of TA as a quantitative indicator of transient cavitation should be of value to the study of ultrasonic biological effects and dosimetry.
描述了一种简单且灵敏的方法，用于测量高强度超声（US）在水溶液中产生的羟基自由基（·OH）数量。该方法基于将无荧光的对苯二甲酸（TA）转化为高荧光的羟基对苯二甲酸（HTA）。通过使用已暴露于参考剂量钴 - 60的TA溶液对荧光分光光度计进行校准。这使得超声产生的荧光读数能够直接以等效厘戈瑞（cGy）读出。·OH的检测限约为1.3×10⁻⁹ M（相当于约0.5 cGy的钴 - 60照射）。在空气饱和的水溶液中，瞬态空化（TC）的阈值为0.7瓦每平方厘米。当TA暴露在软质乙烯基腔室中且仅当腔室绕垂直于超声束的轴旋转时，才会持续产生空化现象。使用TA作为瞬态空化的定量指标，对于超声生物效应和剂量学的研究应具有重要价值。
