To comment at length on the importance of the benzodiazepines seems superfluous within the scope of this preface. No other class of active substances has experienced an even approximately compa rable advance in the past two decades. It is therefore not surprising that the formerly dominant barbiturates and bromocarbamides have had to give way in many fields to the benzodiazepines, which now rank first (Proudfoot and Park 1828]). Closely linked with the great therapeutic importance of the benzodia zepines are analytical problems. Detection and the determination of blood levels can be...