Trace Explosive Detection and Laboratory Validation in Port Security Contexts: A Focus on Apapa Port, Lagos

Port security environments present unique challenges for trace explosive detection due to the high volume of cargo, the diversity of materials in transit, and the elevated consequences of detection failure. This study empirically evaluates trace explosive detection methods and laboratory validation protocols employed at Apapa Port, Lagos, in the context of security screening operations between 2020 and 2024. A laboratory-based empirical design was employed, involving controlled spiking experiments on twenty-five cargo material types using eight explosive compounds at varying concentrations, evaluation of three commercial ion mobility spectrometry (IMS) devices, and comparison of IMS detection performance against confirmatory GC-MS laboratory analysis. Detection rates, false positive rates, and sample throughput were measured under conditions simulating operational port screening. Findings reveal that IMS devices achieved mean detection rates of eighty-four percent for conventional explosives at concentrations above one nanogram per square centimetre, declining to sixty-one percent for low-vapour-pressure explosives such as TATP under ambient port conditions. False positive rates were highest for cargo containing fertiliser residue and petroleum derivatives. GC-MS confirmation reduced false positive classification to below five percent, validating its role as a confirmatory technology. Recommendations include the deployment of dual-technology screening combining IMS with GC-MS confirmation at Apapa Port, and the development of port-specific explosive reference standards for IMS calibration. Keywords: trace explosive detection, port security, Apapa Port, IMS, GC-MS.