离子色谱法测定水中无机阴离子结果

离子色谱法测定水中无机阴离子材料与方法结果2.1标准色谱图分析图2.1为混合标准溶液标准色谱图。由图可见出峰时间顺序为F-，Cl-，NO2-，NO3-，HPO42-和SO42-，与标准对照出峰顺序相同，且各离子间分离良好。对6种无机阴离子色谱图数据分析可知（表2.1），离子间分离度很好，分离度在2.4775.08之间，最小值大于1.5。理论塔板数范围在23955388之间，最小值大于2000，分离柱效果较好。保留时间最后离子SO42-为17.41 min，在保证较好分离度的前提下，分离速度良好。色谱峰的不对成性最大值为2.211，最小值为0.856，对称性良好。图2.1 无机阴离子色谱图Figure 2.1 Inorganic anion chromatogram表2.1 无机阴离子色谱图分析Table 2.1 Chromatographic analysis of inorganic anions峰名称保留时间/min峰底宽/min峰高/m分离度USP理论塔板数/个不对称度F-4.20.3129.4845.0829090.856CL-5.790.3239.6372.47753881.097NO2-6.690.419.4354.28242811.342NO3-9.160.754.0046.5823952.211HPO42-14.660.921.3682.85440590.908SO42-17.411.013.516n.a.47721.0122.2标准曲线与检出限结果显示6种离子的回归方程良好，相关系数均在0.999以上，相对标准偏差范围1.664%3.642%，最大值未超过5.0%。检出限结果如表2.2，检出限的最小值0.02 mg/L，最大值0.12 mg/L。表2.2 6种离子线性范围、回归方程、相关系数、RSD%及检出限（n=7）Table 2.2 The Linear range, the regression equation, correlation coefficient, RSD% and the detection limit of six ion（n=7）离子线性范围回归方程相关系数相对标准偏差%检出限mg/LF-0.078-5.0Y=0.1048X+0.02360.9999271.6640.02CL-1.88-120Y=0.0789X-0.12580.99973.2160.02NO2-0.078-5.0Y=0.0403X-0.15070.9999312.0650.03NO3-0.39-25Y=0.0377X-0.05150.9996563.6420.08HPO42-0.155-10Y=0.0353X-0.00300.9997253.3510.12SO42-1.88-120Y=0.0521X-0.06210.9997492.9120.092.3精密度评价F-，Cl-，NO2-，NO3-，HPO42-和SO42-相对标准偏差分别为1.38%、2.08%、4.45%、1.69%、2.37%、1.81%。6个样本的相对标准偏差范围在1.38%4.45%之间，最大值没有超过5%，说明仪器及实验环境稳定，该方法准确度高，重复性好，见表2.3。表2.3 精密度实验结果（n = 6）Table 2.3 The relative standard deviations investigation of precision （n = 6）离子种类检测结果(mg/L)平均值（mg/L）相对标准偏差（%）样1样2样3样4样5样6F-0.1680.170.1730.1740.1720.1690.171 1.38%CL-21.10722.08322.35622.22222.23422.11922.020 2.08%NO2-0.0830.0930.0910.0910.0870.0850.088 4.45%NO3-4.5454.7344.7794.6664.6734.6724.678 1.69%HPO42-0.2030.210.2040.2110.2010.1990.205 2.37%SO42-51.50153.36254.08652.13452.19953.12752.735 1.81%2.4加标回收率实验由表2.4可知，加标回收率范围在96.58%103.00之间，最大值没有超过105.00%，最小值大于95.00%，加标回收率结果良好，表明该方法准确度高，实验结果可靠。表2.4 加标回收率实验（n=4）Table 2.4 The investigation of the recoveries （n=4）离子名称样品含量（mg/L）（mg/L）加标量（mg/L）加标后含量（mg/L）回收率（%）F-0.10250.100.2205103.00CL-25.205525.0052.0915100.54NO2-0.09400.100.206397.25NO3-5.43505.009.397899.26HPO42-0.28150.300.546396.58SO42-67.441070.00135.556797.312.5兰州段黄河水中无机阴离子检测结果2.5.1黄河兰州段不同城区无机阴离子含量检测结果由表2.5可知，同一城区连续3天的6种无机阴离子含量均在一定范围内波动，其波动范围且均低于国家地表水和饮用水标准。2.5.2黄河兰州段不同城区无机阴离子含量的变化情况由图2.2可知，由上游到下游，Cl-含量呈下降趋势（即西固区安宁区七里河区城关区），NO2-，NO3-，HPO42-和SO42-离子含量整体呈下降趋势，在安宁区有上升，氟离子含量先下降后在城关区略有回升。ANO2-，HPO42-，F-四城区含量BNO3-，CL-，SO42-四城区含量图2.2 6种离子四城区含量变化趋势Figure 2.2 Trends of 6 kinds of ion content5表2.5 不同区段无机阴离子检测结果Table2.5 The results of inorganic anions in different sections区段黄河水兰州段无机阴离子检测结果mg/L采样时间F-CL-NO2-NO3-HPO42-SO42-安宁第一天0.1330.01534.1750.9430.1090.0057.0220.0420.3850.00180.0100.670第二天0.1300.00621.6580.3610.0850.0104.2640.0720.2050.00459.5760.797第三天0.1050.00526.7100.6980.0970.0075.6640.0990.2350.01370.7302.089西固第一天0.1130.00134.3071.1910.0820.0185.0730.1880.2690.00665.8150.982第二天0.1160.00230.7350.7270.0860.0144.4140.0870.2050.00474.7861.059第三天0.1230.00230.5740.3410.0970.0015.1030.0890.2670.05664.8790.694七里河第一天0.0880.00221.3300.8750.0870.0144.2420.0750.2810.02650.6660.091第二天0.0690.00120.0090.3770.0890.0024.1850.0550.2050.00657.1321.061第三天0.1320.00423.7010.8780.0950.0015.2770.0690.2090.00156.7640.624城关第一天0.0960.00120.7820.9360.0940.0014.4110.1700.2170.00149.4850.288第二天0.1110.00521.4690.5160.0900.0024.6380.1030.2060.00764.4581.165第三天0.1700.00321.8490.6570.0910.0084.7570.0320.2040.00153.7240.512黄河兰州段0.1160.01325.6085.04