Volume 99, No. 1178, Pages 241 -31 2 May, 1974THE ANALYSTTHE JOURNAL OF THE SOCIETY FOR AffALY71CAL CHEMISTRYCONTENTSPageR EVIEW PAPERThe Determination o f Some 1.4-Benzodiazepines and their Metabolitesin Body Fluid-. M. Clifford and W. Franklin Smyth . . I . . .ORIGINAL PAPERSA Method f o r the Direct Titrimetric Determination o f Iron(ll1) in SilicateDetermination o f Rubidium, Caesium, Barium and Eight Rare EarthElements in Ultramafic Rocks by Neutron-activation Analysis-A. 0. Brunfelt, 1. Roelandts and E. Steinnes . . . ( I I . - 6 * .The Determlnation o f Iridium and Ruthenium in Rhodium Sponge bySolvent Extraction Followed by Atomic-absorption Spectrophoto-The Use of Ascorbic Acid to Eliminate Interference from Iron in theAluminon Method for Determining Aluminium in Plant and SoilRocks-J.M. Murphy, J. 1. Read and G. A. Sergeant . . . . ..metry-M. A. Ashy and J. B. Headridge , , .. . . . . . .Extracts-T. C. Z. Jayman and S. Sivasubramaniam . . .. ..241273277285296A Method of Collecting and Concentrating Headspace Volatiles f o rGas-chromatographic Analysis-R. E. Hurst . . .. . .A Refractometric Method f o r the Approximate Measurement o f theAlcoholic Strength of Wines a t Room Temperature-J. R, Cooke . .Book Reviews . . w . * I ’. . . . . .. .. * .306310Summaries of Papers In this Issue * . . . .. . . vl, xii. xivPrinted for the Society for Analytical Chemistry by Hdfers Printers Ltd., Cambridge, EnglandAllcommunicationato beaddrer8edtothe Managing Editor,ThsAnalyst. @/lOSauile Row, London, WlX1 AFEnquiries about advertisemts should be addressed to J. Arthur Cook, 9 Uoyd Square, London, WC1X 9BAEntered as Second Class at New York. USA, Post Offic