Development and Validation of High Performance Liquid Chromatographic Analysis of Residual N,N-Dimethylformamide in Spent Medium after Biodegradation by Paracoccus denitrificans SD1

N,N-Dimethylformamide (DMF) is a toxic organic solvent commonly found in the textile and pharmaceutical industrial effluents. The DMF degradation was successfully archived by bacterial strain Paracoccus denitrificans SD1. The study demonstrates the high performance liquid chromatographic (HPLC) approach for the estimation of residual DMF in liquid medium. The investigation mainly focuses on the method development for the detection and quantification of DMF. The bacterium is capable of utilizing DMF (1%？v/v) as the sole source of carbon and nitrogen. Utilization of DMF by the bacterium was investigated at regular intervals of time to check the complete degradation at a particular period. The method was validated based on the precision, accuracy, limit of detection, and limit of quantification. Herein, the method was executed in liquid chromatographic condition which enables direct analysis of aqueous samples from the spent medium avoiding the extraction and prederivatization. This improved method allows estimation of residual DMF from the aqueous medium in adequate ranges of precision and accuracy with 99.17% and 99.43% recovery, respectively. The method was validated by investigating the limit of detection (LOD) and limit of quantification (LOQ) of 0.2 and 0.40？mg/l, respectively. The method was found to be precise for detection of DMF by using liquid chromatography. 1. Introduction N,N-Dimethylformamide (DMF) is a widely used aliphatic organic solvent in chemical, pharmaceutical, and textile industries. Since it is used for recovery of organic compounds, hence considerable amounts of DMF are found in textile and pharmaceutical industrial effluents causing adverse effects on environment and human health [1–4]. Because of its high dielectric constant, it has wide applications in the production of polyurethane, rubber, dyes, wood, leather, films, paper, and pesticides [5]. Globally the demand of DMF is consistently increasing in parallel with industrial activities, resulting in the higher accumulation of DMF in the environment through industrial effluents. It is readily absorbed through oral, dermal, and inhalation exposure [6, 7]. The extents of toxicity induced by DMF are hepatotoxicity, embryotoxicity, teratogenicity, and possible carcinogenicity. Long-term exposure to DMF might also cause irreversible alterations in mitochondrial DNA [5]. The treatment of DMF has gained a considerable attention; it can be recycled by distillation to mother liquors or disposed by incineration [3, 8]. The chemical methods show slower rate of degradation; bioremediation