iv THE ANALYST [April, 1973THE ANALYSTE DlTO RIAL ADVlSO RY BOARDChairman: H. J. Cluley (Wembley)*L. S. Bark (Salford) W. Kemula (Poland)*G. F. Kirkbright (London)G. W. C. Milner (Harwell)G. H. Morrison (U.S.A.)*G. Nickless (Bristol)*J. M. Ottaway (Glasgow)*G. E. Penketh (Billingham)S. A. Price (Tadworth)D. 1. Rees (London)E. B. Sandell (U.S.A.)A. A. Smales, O.B.E. (Harwell)H. E. Stagg (Manchester)E. Srahl (Germany)A. Walsh (Australia)T. S. West (London)P. Zuman (U.S.A.)R. Belcher (Birmingham)L. J. Bellamy, C.B.E. (Waltham Abbey)L. S. Birks (U.S.A.)E. Bishop (Exeter)E. A. M. F. Dahmen (The NetherlandsjA. C. Docherty (Billingham)D. Dyrssen (Sweden)*W. T. Elwell (Birmingham)*D. C. Garratt (London)*R. Goulden (Sittingbourne)*R. C.Chirnside (Wembley)J. Hoste (Belgium)D. N. Hume (U.S.A.)H. M. N. H. Irving (Leeds)A. G. Jones (Welwyn Garden City)M. T. Kelley (U.S.A.)*A. Townshend (Birmingham)*J. A. Hunter (Edinburgh)* Members of the Board serving on the Executive Committee.N O T I C E TO SUBSCRIBERSSubscriptions for The Analyst, Analytical Abstracts and Proceedings should beThe Chemical Society, Publications Sales Office,Blackhorse Road, Letchworth, Herts.Rates for 1973(other than Members of the Society)sent to:(a) The Analyst, Analytical Abstracts, and Proceedings, with indexes . . . . €37.00(b) The Analyst, Analytical Abstracts printed on one side of the paper (without(c) The Analyst, Analytical Abstracts printed on one side of the paper (withindex), and Proceedings .. . . . . . . . . . . . . f38.00index), and Proceedings . . . . . . . . . . . . . . f45.00The Analyst and Analytical Abstracts without Proceedings-(d) The Analyst and Analytical Abstracts, with indexes . . . . . . . . €34.00(e) The Analyst, and Analytical Abstracts printed on one side of the paper (without index) f 35.00(f) The Analyst, and Analytical Abstracts printed on one side of the paper (with. . . . . . . . . . . . . . . . . .index) €42-00 . . . . . . . . . . . . . . . . . .(Subscriptions are NOT accepted for The Analyst and/or for Proceedings aloneApril, 19731 SUMMARIES OF PAPERS IN THIS ISSUESummaries of Papers in this IssueThe Determination of Bis(tri-n-butyltin) Oxide and Di-n- butyltinOxide in Preserved Softwood by Atomic-absorptionSpectrophotometry and PolarographyMethods are described for the determination of the total organotincompounds by atomic-absorption spectrophotometry and for the specificdetermination of bis(tri-n-butyltin) oxide and di-n-butyltin oxide by atomic-absorption spectrophotometry and polarography.Bis(tri-n-butyltin) oxideand di-n-butyltin oxide are extracted from the wood with hydrochloricacid - ethanol solution and separated from each other and from wood extrac-tives, fungicides and insecticides by adsorption on to Amberlite CG-120cation-exchange resin followed by elution with solutions containing differentconcentrations of hydrochloric acid in ethanol.The procedures have been used to determine bis(tri-n-butyltin) oxide anddi-n-butyltin oxide in Scots pine, Corsican pine, Western hemlock, Japaneselarch, Sitka spruce, Douglas fir and Western red cedar.(The late) A.I. WILLIAMSDepartment of the Environment, Building Research Establishment, Princes Ris-borough Laboratory, Princes Risborough, Aylesbury, Buckinghamshire, HP17 9PX.Analyst, 1973, 98, 233-242.An Improved Method for the Determination of Whole Blood Leadby Using an Atomic-absorption TechniqueThe Delves technique for measuring whole blood lead has been con-siderably improved by wet ashing with aqua regia instead of simply dryingwith hydrogen peroxide. Smoke is eliminated, and the reproducibility ofthe method is improved.G. ALAN ROSE and ELIZABETH G. WILLDENDepartment of Pathology, St.Peter’s Hospitals, Endell Street, London, W.C.2.Analyst, 1073, 98, 243-246.Bis(6-Methyl-2-pyridyl)glyoxal Dihydrazone as a SpectrophotometricReagent for the Rapid Determination of Copper in Alkalis, Milk and BrineThe synthesis, characteristics and analytical applications of bis (6-methyl-2-pyridyl) glyoxal dihydrazone are described. This compound producescoloured solutions selectively with copper(1) ions (Amax. = 440 nm, =8.7 x lo3 1 mol-l cm-l) that can be extracted into various organic solvents;it behaves as a cuproine-type reagent. The 1: 1 orange - yellow copper(1)complex has been used for the spectrophotometric determination of traceamounts of copper in saturated brine, alkalis and milk. The most importantadvantage of using this reagent is the total recovery of copper that is possiblefrom ammoniacal solutions.M. VALCARCEL and F. PIN0Department of Analytical Chemistry, University of Seville, Seville, Spain.Analyst, 1973, 98, 246-250.An Electrical Conductivity Detector for Paper, Thin-layerand Column ChromatographyAn electrical conductivity detector has been developed for applicationto the paper, thin-layer and column chromatography of ionic substances.Two arms of an a.c. Wheatstone bridge comprise two pairs of electrodesapplied directly on to the separating layer so that a signal ensues from thebridge when a chromatographic spot passes one electrode pair while the otherpair is traversed by the eluting agent. The sensitivity is about 1 pg and theprecision is about 2 to 3 per cent.V. DI STEFAN0 and P. MARINICentro Sperimentale Metallurgico, Via di Caste1 Romano, Rome, 1 taly.Analyst, 1973, 98, 251-256.