Analyst, November 1996, Vol. 121 167N The Royal Society of Chemistry Library can usually supply copies of cited articles. For further details contact: The Library, Royal Society of Chemistry, Burlington House, Piccadilly, London W1V OBN, UK. Tel: +44 (O)171-437 8656. Fax: +44 (0) 17 1-287 9798. Telecom Gold 84: BUR21 0. Electronic Mailbox (Internet) LIBRARY@RSC.ORG. If the material is not available from the Society’s Library, the staff will be pleased to advise on its availability from other sources. Please note that copies are not available from the RSC at Thomas Graham House, Cambridge. ~ Future Issues Will Include Amperometric Biosensor for Tyrosinase Inhibitors in Pure Organic Phase-Shaojun Dong, Qing Deng Rapid and Accurate Determination of Manganese in Washing PowdersDetergents Using Alkali Fusion and Inductively Coupled Plasma Techniques-Kym E.Jarvis, J. G. Williams, B. C. H. Gibson, E. Temmerman, C. De Cuyper Wall-jet Flow Cell for Stripping Potentiometry-Daniel Jagner, R. Ratana-Ohpas, W. Ratana-Ophas, P. Kanatharana Micro-optical Ring Electrode: Development of a Novel Elec- trode for Photoelectrochemistry-Colin Boxall, Gaelle I. Pennarun, Danny O’Hare Determination of Volatile Organic Compounds in Air by Dehumidified and Ventilated Diffusive Sampler, Thermal Desorption and Gas Chromatography-Flame Ionization Detec- tion-Y. S. Fung, Zucheng Wu Reagentless Amperometric Glucose Dehydrogenase Biosensor Based on Electrocatalytic Oxidation of Nicotinamide Adenine Dinucleotide Reduced Form by Osmium Phenanthrolinedione Mediator-Ioanis Katatis, Maria Hedenmo, Arantazu Narvaez, Elena Dominguez Flow System for Liquid Sample Introduction in Arc/Spark Excitation Sources-Celio Pasquini, Carlos Roberto Bellato Sensitive Densitometry for the Platelet-activating Factor and Other Phospholipid Determinations in Human Tears- Toshihisa Ohyama, Chiyo Matsubara, Kiyoko Takamura Application of Nafion-coated Mercury Film Electrodes to the Microdetermination of Formaldehyde by Differential-pulse Voltammetry-Wing Hong Chan, Hao Huang Competitive Enzyme-linked Immunosorbent Assay for the Determination of the Phenylurea Herbicide Chlortoluron in Water and Biological Fluids-Fawaz M.Katmeh, W. Aherne, D. Stevenson Volatile Organic Metabolites Associated With Some Toxic Fungi and Their Mycotoxins-Anna-Liisa Pasanen, Sanna Lappalainen, Pertti Pasanen Optical Sensor for Oxygen Concentrations Using a Porphyrin- doped Sol-Gel Glass-Sang-Kyung Lee, Ichiro Okura pK,, Values of the Opened Form of a Thieno-1,2,4-triazolo- 1,4-diazepine in Water-Beatrice Legouin, Jean-Louis Burgot Optical Chemical Sensors For Pharmaceutical Analysis Using 1,4-Bis( 1,3-benzoxazole)benzene as Sensing Material-Ying Wang, Kemin Wang, Wanhui Liu, Guoli Shen, Ruqin Yu Determination of Ammonia in Waste Waters by a Differential pH Method Using Flow Injection Potentiometry and the Nonactin-based Sensor-Robert W.Cattrall, Hongda Shen, Terence J. Cardwell Direct Determination of Butyl- and Phenyltin Compounds as Chlorides Using Gas Chromatography and Flame Photometric Detection-G. Lespes, C. Carlier-Pinasseau, M. Potin-Gautier, M. Astruc Simultaneous Stopped-flow Determination of Paracetamol, Acetylsalicylic Acid and Caffeine in Pharmaceutical Formula- tions by Partial Least Squares-Fourier Transform Infrared Spectrometry-Miguel de la Guardia, Zouhair Bouhsain, Salvador Garrigues Effect of Storage on the Recovery of Different Types of Pesticides Using a Solid-phase Extraction Method-A. Pena, C. de la Colina, F. Sanchez-Rasero, G. Dios, E. Romero Optical Biosensing of Nitrate Ions Using a Sol-Gel Im- mobilized Nitrate Reductase-Jonathan W. Aylott, David J. Richardson, David A. Russell Quantitative Analysis of Sulfated Calcium Carbonates Using Raman Spectroscopy and X-ray Powder Diffraction-Christos G. Kontoyannis, Malvina G. Orkoula, Petros G. Kou tsou kos COPIES OF CITED ARTICLES