Paper describes the Post Nuclear Magnetic Resonance Spectroscopic analysis of proficiency test samples using Phosphorus NMR. In our study two-dimensional 1H-31P NMR method was optimized effectively for identification of Chemical weapon convention related scheduled organophosphorus compounds in the environmental samples provided by OPCW during proficiency test, while second report is on post analysis of proficiency test sample, carried out to reexamine the samples to observe the missed organophosphorus compounds and to investigate the causes of missing of organophosphorus chemicals during analysis.