RESUMEN
One of the advanced oxidative processes is gamma irradiation, an efficient technique for removing pesticides and pharmaceutical products. Radiolytic degradation leads to free radical's formation, which facilitates molecular lesion and breaks the chemical bonds. The use of pharmaceutical compounds, such as hydroxychloroquine (HCQ), is increasing nowadays due to the Covid 19 pandemic situation. This study focused on gamma radiation-induced degradation of HCQ in aqueous solution. The degradation was monitored by High-Performance Liquid Chromatography (HPLC) using an Eclipse XDB-C18 column (150 × 3.0 mm, 3.5 µm) and a mobile phase composed of 94% water (phosphate buffer at pH = 3.6) and 6% acetonitrile, with a DAD detection at λ = 343 nm. The effect of different gamma radiation doses (from 0.05 to 3 kGy) was investigated. Chromatographic analysis shows that 1 kGy dose is effective to degrade completely HCQ at 20 ppm and following a first-pseudo-kinetic order with a dose constant corresponding to 4.2 kGy-1. A comparison was done between gamma degradation and other methods. LC-QToF-MS/MS identified the intermediate products, and their kinetic constants were determined. A mechanism pathway was proposed for HCQ degradation under gamma irradiation.
RESUMEN
An automated solid-phase extraction-liquid chromatography- tandem mass spectrometry (SPE-LC-MS-MS) method using the Spark Holland Symbiosis Pharma SPE-LC coupled to a Waters Quattro Micro MS-MS was developed for the analysis of 6-acetylmorphine (6-AM) in human urine specimens. The method was linear (R² = 0.9983) to 100 ng/mL, with no carryover at 200 ng/mL. Limits of quantification and detection were found to be 2 ng/mL. Interrun precision calculated as percent coefficient of variation (%CV) and evaluated by analyzing five specimens at 10 ng/mL over nine batches (n = 45) was 3.6%. Intrarun precision evaluated from 0 to 100 ng/mL ranged from 1.0 to 4.4%CV. Other opioids (codeine, morphine, oxycodone, oxymorphone, hydromorphone, hydrocodone, and norcodeine) did not interfere in the detection, quantification, or chromatography of 6-AM or the deuterated internal standard. The quantified values for 41 authentic human urine specimens previously found to contain 6-AM by a validated gas chromatography (GC)-MS method were compared to those obtained by the SPE-LC-MS-MS method. The SPE-LC-MS-MS procedure eliminates the human factors of specimen handling, extraction, and derivatization, thereby reducing labor costs and rework resulting from human error or technique issues. The time required for extraction and analysis was reduced by approximately 50% when compared to a validated 6-AM procedure using manual SPE and GC-MS analysis.
