Department of Chemistry, and the Texas Research Institute for Environmental Studies, Sam Houston State University, Huntsville, TX, USA.
Environ Technol. 2009 Nov;30(12):1327-35. doi: 10.1080/09593330902998082.
The selenocyanate anion, SeCN(-), has been reported in wastewater from refineries whose petroleum comes from Se-rich marine shales. A metalloid-resistant bacterium was exposed to aqueous solutions of SeCN(-) to examine the relative toxicity of SeCN(-), and the results were compared with the toxicity of selenate and selenite and another G16 metalloid oxyanion, tellurite. We also determined the volatile organo-selenium species produced by bacterial cultures amended with selenocyanate anion, and we investigated a solid phase preconcentration technique for collecting SeCN(-) from aqueous samples with different ionic strengths and subsequent detection using capillary electrophoresis. The relative toxicity of SeCN(-) is comparable to that of selenate and selenite using the metalloid-resistant bacterium LHVE as the test organism. Tellurite was more toxic at all concentrations examined than all three selenium-containing anions, SeO4(2-), SeO3(2-), SeCN(-). Live cultures of LHVE amended with 1 mM NaSeCN produced volatile organo-sulphides and organo-selenides that could be collected in headspace using a solid phase microextraction fibre. The bioprocessing, i.e. the reduction and methylation of SeCN(-), is similar to that of selenate and selenite by other metalloid-resistant bacteria. An aqueous 1.0 mM solution of SeCN(-) could be captured from solution on solid-phase extraction (SPE) cartridges using an aminopropyl-based stationary phase. Selenocyanate anions, slowly pumped into a wetted SPE cartridge, were trapped on the cartridge's solid phase and were subsequently eluted, thereby providing an increase in concentration above that of the original SeCN(-)-containing solution. Preconcentration factors of 3.9 were achieved using a mixed sodium hydroxide/methanol elution solvent and by adding NaCl to aqueous SeCN(-) before loading on the SPE cartridge.
硒氰酸根阴离子，SeCN(-)，已在炼油厂的废水中被报道，这些炼油厂的石油来自富含硒的海洋页岩。一种类金属抗性细菌暴露于硒氰酸盐溶液中，以研究 SeCN(-)的相对毒性，并将结果与硒酸盐和亚硒酸盐以及另一种 G16 类金属含氧阴离子碲酸盐的毒性进行比较。我们还确定了细菌培养物在添加硒氰酸根阴离子时产生的挥发性有机硒物种，并研究了一种固相预浓缩技术，用于从不同离子强度的水样中收集 SeCN(-)，并随后使用毛细管电泳进行检测。使用类金属抗性细菌 LHVE 作为测试生物，SeCN(-)的相对毒性可与硒酸盐和亚硒酸盐相媲美。在所有研究的浓度下，碲酸盐都比所有三种含硒阴离子，SeO4(2-)、SeO3(2-)、SeCN(-)，毒性更大。用 1mM NaSeCN 处理的 LHVE 活培养物产生了挥发性有机硫化物和有机硒化物，可以使用固相微萃取纤维在顶空收集。生物处理，即 SeCN(-)的还原和甲基化，与其他类金属抗性细菌对硒酸盐和亚硒酸盐的处理相似。1.0mM 的 SeCN(-)水溶液可以通过使用基于氨基丙基的固定相在固相萃取（SPE）小柱上从溶液中捕获。硒氰酸根阴离子，缓慢地泵入湿润的 SPE 小柱，被小柱的固相捕获，随后被洗脱，从而在原始含 SeCN(-)溶液的浓度之上提供了浓度的增加。使用混合氢氧化钠/甲醇洗脱溶剂并在将 SeCN(-)加载到 SPE 小柱之前向水溶液中添加 NaCl，可以实现 3.9 的预浓缩因子。
