国产bbaaaaa片,成年美女黄网站色视频免费,成年黄大片,а天堂中文最新一区二区三区,成人精品视频一区二区三区尤物

首頁> 中文期刊> 《石油煉制與化工》 >溴化容量法測(cè)定水質(zhì)中揮發(fā)酚兩種標(biāo)準(zhǔn)方法的比較

溴化容量法測(cè)定水質(zhì)中揮發(fā)酚兩種標(biāo)準(zhǔn)方法的比較

     
  • 摘要
  • 著錄項(xiàng)
  • 相似文獻(xiàn)
  • 相關(guān)主題

摘要

從測(cè)定范圍、分析步驟、溴酸鉀-溴化鉀及滴定劑消耗量、精密度和準(zhǔn)確度等方面對(duì)溴化容量法測(cè)定水質(zhì)中揮發(fā)酚GB 7491-1987和HJ 502-2009兩種標(biāo)準(zhǔn)進(jìn)行了比較.結(jié)果表明:HJ 502-2009標(biāo)準(zhǔn)明確了揮發(fā)酚的測(cè)定范圍為0.1～45.0 mg/L,增加了精密度和準(zhǔn)確度條款,預(yù)蒸餾方式由二次蒸餾改為一次蒸餾；操作中固定溴酸鉀溴化鉀溶液的體積為3 mL,僅一個(gè)空白試驗(yàn)可測(cè)試多個(gè)樣品,更適合試樣的批量分析.當(dāng)100 mL餾出液中揮發(fā)酚質(zhì)量為2.35 mg時(shí),兩種標(biāo)準(zhǔn)消耗的溴酸鉀-溴化鉀溶液的量相同；當(dāng)l00mL餾出液中揮發(fā)酚質(zhì)量小于2.35 mg時(shí),HJ 5022009標(biāo)準(zhǔn)消耗溴酸鉀溴化鉀溶液和硫代硫酸鈉標(biāo)準(zhǔn)溶液的量均大于GB 7491-1987標(biāo)準(zhǔn)中溴酸鉀-溴化鉀溶液和硫代硫酸鈉標(biāo)準(zhǔn)溶液用量,當(dāng)100mL餾出液中揮發(fā)酚質(zhì)量大于2.35mg時(shí),結(jié)果正好相反.建議溴酸鉀溴化鉀溶液的加入量由3 mL變?yōu)?.5 mL,100mL餾出液中揮發(fā)酚的質(zhì)量小于2.35 mg,以便于操作并提高試驗(yàn)準(zhǔn)確度.%Two standards for determination of volatile phenolic compounds with bromine method, GB 7491 -1987 and HJ 502-2009, were compared including determination range, analysis procedure, consumption of potassium bromated-potassium bromide solution and titrant, precision and accuracy. Comparison results show that in HJ 502-2009 standard method,the determination range of volatile phenolic compounds (0. 1-45. 0 mg/L) is definite,which is not clear in GB 7491-1987; the content of precision and accuracy is added, and sample pre-distillation is only once, which is twice in GB 7491 - 1987. According to HJ 502-2009 standard method,for 100 mL distillate,the adding volume of potassium bromated-potassium bromide solution is fixed to 3 mL,thus one blank test is enough for multiple samples analysis,which is more suitable to batch analysis. When the content of volatile phenolic compounds in 100 mL distillate is 2. 35 mg,the consumptions of potassium bromated-potassium bromide solution of these two standard method are the same; when the content of volatile phenolic compounds in 100 mL distillate is less than 2. 35 mg,the consumption of potassium bromated-potassium bromide solution and sodium thiosulfate standard solution in HJ 502-2009 standard method is more than those in GB 7491 -1987; however,it is contrary when the content of volatile phenolic compounds in 100 mL distillate is more than 2. 35 mg. It is suggested to change the fixed volume of potassium bromated-potassium bromide solution from 3 mL to 2. 5 mL,and the content of volatile phenolic compounds in 100 mL distillate should be less than 2. 35 mg for easy operation and better accuracy.

著錄項(xiàng)

相似文獻(xiàn)

  • 中文文獻(xiàn)
  • 外文文獻(xiàn)
  • 專利
獲取原文

客服郵箱：kefu@zhangqiaokeyan.com

京公網(wǎng)安備：11010802029741號(hào) ICP備案號(hào)：京ICP備15016152號(hào)-6 六維聯(lián)合信息科技 (北京) 有限公司?版權(quán)所有

  • 客服微信

  • 服務(wù)號(hào)