Fayad Paul B, Zamyadi Arash, Broseus Romain, Prévost Michèle, Sauvé Sébastien
Department of Chemistry, Université de Montréal, Montreal, QC, Canada.
Department of Civil, Geological and Mining Engineering, École Polytechnique de Montréal, Montreal, QC, Canada.
Chem Cent J. 2013 May 15;7:84. doi: 10.1186/1752-153X-7-84. eCollection 2013.
This study investigated the oxidation of selected progestagenic steroid hormones by potassium permanganate at pH 6.0 and 8.0 in ultrapure water and wastewater effluents, using bench-scale assays. Second order rate constants for the reaction of potassium permanganate with progestagens (levonorgestrel, medroxyprogesterone, norethindrone and progesterone) was determined as a function of pH, presence of natural organic matter and temperature. This work also illustrates the advantages of using a novel analytical method, the laser diode thermal desorption (LDTD-APCI) interface coupled to tandem mass spectrometry apparatus, allowing for the quick determination of oxidation rate constants and increasing sample throughput.
The second-order rate constants for progestagens with permanganate determined in bench-scale experiments ranged from 23 to 368 M(-1) sec(-1) in both wastewater and ultrapure waters with pH values of 6.0 and 8.0. Two pairs of progestagens exhibited similar reaction rate constants, i.e. progesterone and medroxyprogesterone (23 to 80 M(-1) sec(-1) in ultrapure water and 26 to 149 M(-1) sec(-1) in wastewaters, at pH 6.0 and 8.0) and levonorgestrel and norethindrone (179 to 224 M(-1) sec(-1) in ultrapure water and 180 to 368 M(-1) sec(-1) in wastewaters, at pH 6.0 and 8.0). The presence of dissolved natural organic matter and the pH conditions improved the oxidation rate constants for progestagens with potassium permanganate only at alkaline pH. Reaction rates measured in Milli-Q water could therefore be used to provide conservative estimates for the oxidation rates of the four selected progestagens in wastewaters when exposed to potassium permanganate. The progestagen removal efficiencies was lower for progesterone and medroxyprogesterone (48 to 87 %) than for levonorgestrel and norethindrone (78 to 97%) in Milli-Q and wastewaters at pH 6.0-8.2 using potassium permanganate dosages of 1 to 5 mg L(-1) after contact times of 10 to 60 min.
This work presents the first results on the permanganate-promoted oxidation of progestagens, as a function of pH, temperature as well as NOM. Progestagen concentrations used to determine rate constants were analyzed using an ultrafast laser diode thermal desorption interface coupled to tandem mass spectrometry for the analysis of water sample for progestagens.
本研究采用实验室规模的试验，研究了高锰酸钾在pH值为6.0和8.0的超纯水和废水流出物中对选定的孕激素类甾体激素的氧化作用。确定了高锰酸钾与孕激素（左炔诺孕酮、甲羟孕酮、炔诺酮和孕酮）反应的二级速率常数与pH值、天然有机物的存在及温度的关系。这项工作还说明了使用一种新型分析方法的优点，即与串联质谱仪联用的激光二极管热解吸（LDTD-APCI）接口，可快速测定氧化速率常数并提高样品通量。
在实验室规模实验中测定的孕激素与高锰酸钾的二级速率常数，在pH值为6.0和8.0的废水和超纯水中范围为23至368 M⁻¹ s⁻¹。两对孕激素表现出相似的反应速率常数，即孕酮和甲羟孕酮（在pH值为6.0和8.0时，超纯水中为23至80 M⁻¹ s⁻¹，废水中为26至149 M⁻¹ s⁻¹）以及左炔诺孕酮和炔诺酮（在pH值为6.0和8.0时，超纯水中为179至224 M⁻¹ s⁻¹，废水中为180至368 M⁻¹ s⁻¹）。溶解的天然有机物的存在和pH条件仅在碱性pH下提高了孕激素与高锰酸钾的氧化速率常数。因此，在超纯水（Milli-Q水）中测得的反应速率可用于保守估计四种选定孕激素在废水中暴露于高锰酸钾时的氧化速率。在pH值为6.0 - 8.2的超纯水和废水中，使用1至5 mg L⁻¹的高锰酸钾剂量，接触10至60分钟后，孕酮和甲羟孕酮的去除效率（48%至87%）低于左炔诺孕酮和炔诺酮（78%至97%）。
本研究首次给出了高锰酸钾促进的孕激素氧化作用的结果，该结果是pH值、温度以及天然有机物含量的函数。用于确定速率常数的孕激素浓度，采用与串联质谱联用的超快速激光二极管热解吸接口对水样中的孕激素进行分析。
