| Title | UV and H202/UV degradation of a pharmaceutical intermediate in aqueoussolution |
| Abstract | The degradation of 5-methyl-1,3,4-thiadiazole-2-thiol (NMTD), a pharmaceutical intermediate found in some aquifers of Northern Italy, has been investigated by means of UV and UV/H2O2 treatments. The study has been carried out with a 17 W low pressure mercury lamp at room temperature, using a (100)/(1)(H2O2)/(MMTD) molar ratio. The results have demonstrated that: (i) with an initial MMTD concentration of 1 mg/1, 90 % MMTD removal can be achieved within 1 hour or less than 5 minutes by UV or UV/H2O2 respectively; (ii) the sole UV irradiation does not cause any MMTD mineralization; (iii) with an initial MMTD concentration of 50 mg/1, 4 hours of UV/H2O2 treatment lead to an almost complete mineralization of the MMTD organic sulfur and to a partial mineralization of carbon (59%) and nitrogen (14%). The identification of degradation by-products, performed by HPLC-UV-MS analysis, revealed that the sole UV irradiation gives rise to the MMTD transformation into a single by-product that continuously accumulates in the solution. Conversely, the UV/H2O2 treatment forms seven intermediates that undergo further degradation through the breakdown of the thiadiazole ring. On the basis of the obtained results a degradation pathway has been proposed |
| Source | Annali di chimica (Testo stamp.) 92, pp. 41–51 |
| Keywords | Advanced Oxidation ProcessesPharmaceutical IntermediatesUV/H2O2 treatments |
| Journal | Annali di chimica (Testo stamp.) |
| Editor | Societa chimica italiana, Roma, Italia |
| Year | 2002 |
| Type | Articolo in rivista |
| Authors | Lopez A., Bozzi A., Mascolo G., Ciannarella R., Passino R. |
| Text | 42082 2002 Advanced Oxidation Processes Pharmaceutical Intermediates UV/H2O2 treatments UV and H202/UV degradation of a pharmaceutical intermediate in aqueoussolution Lopez A., Bozzi A., Mascolo G., Ciannarella R., Passino R. CNR Istituto di Ricerca sulle Acque The degradation of 5 methyl 1,3,4 thiadiazole 2 thiol NMTD , a pharmaceutical intermediate found in some aquifers of Northern Italy, has been investigated by means of UV and UV/H2O2 treatments. The study has been carried out with a 17 W low pressure mercury lamp at room temperature, using a 100 / 1 H2O2 / MMTD molar ratio. The results have demonstrated that i with an initial MMTD concentration of 1 mg/1, 90 % MMTD removal can be achieved within 1 hour or less than 5 minutes by UV or UV/H2O2 respectively; ii the sole UV irradiation does not cause any MMTD mineralization; iii with an initial MMTD concentration of 50 mg/1, 4 hours of UV/H2O2 treatment lead to an almost complete mineralization of the MMTD organic sulfur and to a partial mineralization of carbon 59% and nitrogen 14% . The identification of degradation by products, performed by HPLC UV MS analysis, revealed that the sole UV irradiation gives rise to the MMTD transformation into a single by product that continuously accumulates in the solution. Conversely, the UV/H2O2 treatment forms seven intermediates that undergo further degradation through the breakdown of the thiadiazole ring. On the basis of the obtained results a degradation pathway has been proposed 92 Le ricerche, i cui risultati sono riportati nel lavoro di riferimento, sono state avviate in seguito alla notizia, apparsa su importanti quotidiani nazionali , che in alcune falde del nord Italia erano state rilevate concentrazioni significative di intermedi di antibiotici cefalosporine veicolati da scarichi di impianti di depurazione Bozzi A., Lopez A., Mascolo G., Ciannarella R., Tiravanti G. Annali di Chimica, 2002, 92 1 2 , 41 51. 2002_Ann_Chimica.pdf Articolo in rivista Societa chimica italiana 0003 4592 Annali di chimica Testo stamp. Annali di chimica Testo stamp. Ann. chim. Testo stamp. Annali di chimica. Testo stamp. antonio.lopez LOPEZ ANTONIO ruggiero.ciannarella CIANNARELLA RUGGIERO giuseppe.mascolo MASCOLO GIUSEPPE |
