针对土壤中全硼测定存在难消解、干扰大、易挥发损失等问题,利用碱熔法、微波消解法以及微敞开石墨消解法对土壤全硼进行了测定分析,优化了消解条件,并对三种消解方式进行了验证对比。结果表明:碱熔剂种类以及用量会对碱熔法的准确性造...针对土壤中全硼测定存在难消解、干扰大、易挥发损失等问题,利用碱熔法、微波消解法以及微敞开石墨消解法对土壤全硼进行了测定分析,优化了消解条件,并对三种消解方式进行了验证对比。结果表明:碱熔剂种类以及用量会对碱熔法的准确性造成较大影响,选择KOH作为碱熔剂,并且KOH添加量为3.0 g时,可以获得更准确的结果;加酸种类以及赶酸温度的选择对微波消解法测定结果影响较大,选择加酸体系(5 mL HNO_(3)+1 mL HCl+3 mL HF+1.5 mL H_(3)PO_(4)),赶酸时温度选择170℃,测试效果较好;不同的加酸体系以及消解温度同样会引起微敞开石墨消解法测定结果出现较大误差,选择加酸体系(5 mL HNO_(3)+1 mL HClO_(4)+3 mL HF+1.5 mL H_(3)PO_(4)),消解温度设为170℃,测定结果更可靠。方法验证对比结果表明,碱熔法检出限为0.7 mg/kg,微波消解法检出限为0.9 mg/kg,微敞开石墨消解法检出限为1.0 mg/kg,均满足分析测定的要求。三种消解方式测定的准确度和精密度均符合要求,均可用于土壤全硼的测定,并且实际样品测定结果无显著性差异。三种消解方式优缺点和适用范围不同,实际测试时可以根据样品数量及样品中全硼大致含量等选择具体的消解方式。建立的方法可以为第三次全国土壤普查内业检测提供参考和借鉴。展开更多
The corrosion of ECR glass fiber was investigated by the analysis methods of weight loss ratio under different acids and at various durations.Weight loss,leaching of cations,and surface composition of ECR glass fiber ...The corrosion of ECR glass fiber was investigated by the analysis methods of weight loss ratio under different acids and at various durations.Weight loss,leaching of cations,and surface composition of ECR glass fiber were analyzed.The corrosion mechanism of ECR glass fiber in acid environment was also discussed.The experimental results showed that the corrosion degree of ECR glass fiber in different acids obeyed the order： HNO3〉H2SO4〉HCl.The acid effects on corrosion of ECR glass fiberis were totally different.Hydrochloric acid mainly destroyed the network structure of [AlO4],while sulfuric acid and nitric acid mainly destroyed the structure of [SiO4].The acid resistance of ECR glass fiber is much better than that of E glass fiber due to the generation of intermediate product silicic acid gel Si（OH）4 during ion exchange.It can adhere to the glass surface to form a thin film and hinder the proceeding of corrosion.展开更多
文摘针对土壤中全硼测定存在难消解、干扰大、易挥发损失等问题,利用碱熔法、微波消解法以及微敞开石墨消解法对土壤全硼进行了测定分析,优化了消解条件,并对三种消解方式进行了验证对比。结果表明:碱熔剂种类以及用量会对碱熔法的准确性造成较大影响,选择KOH作为碱熔剂,并且KOH添加量为3.0 g时,可以获得更准确的结果;加酸种类以及赶酸温度的选择对微波消解法测定结果影响较大,选择加酸体系(5 mL HNO_(3)+1 mL HCl+3 mL HF+1.5 mL H_(3)PO_(4)),赶酸时温度选择170℃,测试效果较好;不同的加酸体系以及消解温度同样会引起微敞开石墨消解法测定结果出现较大误差,选择加酸体系(5 mL HNO_(3)+1 mL HClO_(4)+3 mL HF+1.5 mL H_(3)PO_(4)),消解温度设为170℃,测定结果更可靠。方法验证对比结果表明,碱熔法检出限为0.7 mg/kg,微波消解法检出限为0.9 mg/kg,微敞开石墨消解法检出限为1.0 mg/kg,均满足分析测定的要求。三种消解方式测定的准确度和精密度均符合要求,均可用于土壤全硼的测定,并且实际样品测定结果无显著性差异。三种消解方式优缺点和适用范围不同,实际测试时可以根据样品数量及样品中全硼大致含量等选择具体的消解方式。建立的方法可以为第三次全国土壤普查内业检测提供参考和借鉴。
基金Funded by the National Natural Science Foundation of China(No.51472191)the Wuhan City Chenguang Project(No.2014070404010208)+2 种基金the Natural Science Foundation of Hubei Province(Nos.2014CFB343 and 2014CFB859)the Doctoral Program of Higher Education(No.20130143110013)the Key Technology Innovation Project of Hubei Province(No.2013AAA017)
文摘The corrosion of ECR glass fiber was investigated by the analysis methods of weight loss ratio under different acids and at various durations.Weight loss,leaching of cations,and surface composition of ECR glass fiber were analyzed.The corrosion mechanism of ECR glass fiber in acid environment was also discussed.The experimental results showed that the corrosion degree of ECR glass fiber in different acids obeyed the order： HNO3〉H2SO4〉HCl.The acid effects on corrosion of ECR glass fiberis were totally different.Hydrochloric acid mainly destroyed the network structure of [AlO4],while sulfuric acid and nitric acid mainly destroyed the structure of [SiO4].The acid resistance of ECR glass fiber is much better than that of E glass fiber due to the generation of intermediate product silicic acid gel Si（OH）4 during ion exchange.It can adhere to the glass surface to form a thin film and hinder the proceeding of corrosion.
