reported to the Conference on Disarmament in annual reports. During the current year, the Defence Research Establishment conducted an investigation to optimize the sample preparation method referred to as sorbent extraction. The aim of the investigation was to find a general procedure which can be used for screening samples suspected of being contaminated with chemical warfare agents. The sorbent extraction technique is based on the principle of absorption of chemical compounds from an aqueous solution passed through a cartridge containing a polymer sorbent. With this technique the chemical agents .are retained on the sorbent. This procedure has the advantages of not requiring advanced laboratorv equipment and of being executable in the field close to a contaminated area. The sample is concentrated on a cartridge, thus reducing the quantity of material which has to be transported back to the laboratory and also making it easy to handle. There are several factors which may affect the efficiency of sorbent extraction used in verification of alleged use of chemical weapons. In this report different non-polar sorbents have been tested to find which is most efficient in retaining the chemical warfare agents tabun, sarin, soman, VX, mustard gas and some related phosphorous compounds from aqueous solutions. CD/PV.562 3 (Mr. Vareny, Norway) Both the amount of sorbent and the sample volume have been examined to find the optimal combination. Another factor which I would like to stress in particular is the temperature conditions for the samples, both during storage and transport. This has been studied to find the requirements needed to prevent degradation of the chemical warfare agents and thereby increase the possibility for a reliable verification. The second working paper I have the honour to introduce today gives a summary of the results of the International Workshop on Seismological 
**Analysis**
The text appears to be discussing a scientific investigation conducted by a defence research establishment, focusing on the development of a method for detecting and verifying the presence of chemical warfare agents. The language used is technical and specialized, indicating a strong emphasis on scientific research and technology.

**Category**
Science and technology