HPLC高效液相色谱故障排除及解决办法资料.ppt

色谱峰保留时间问题: 保留时间飘忽不定(各次运行之间) 系统不稳定或未达化学平衡 泵压力不稳(泵头里有气泡) 进样体积过大或样品浓度过大 温度波动 流动相混合不均匀 色谱柱被污染 色谱图常见问题分析(二) 色谱峰保留时间问题: 保留时间增加或减少(各次运行之间) 系统不稳定或化学平衡不足 泵流速变化 温度变化 色谱柱污染,柱效下降 流动相被污染 溶剂入口过滤器堵或管路堵塞 系统渗漏 色谱图常见问题分析(二)(续) 色谱图常见问题分析(二)(续) 色谱峰保留时间问题: 保留时间改变到一个新的恒定值 流动相不正确或其组成不正确 泵流速变化 实际输液的流速不正确(泵失灵或故障) 环境温度变化；柱温不正确 色谱柱尺寸或类型不正确 色谱柱被污染 流动相含有稳定剂或稳定剂发生变化 输液系统的梯度滞后体积不正确 * Hi There... * ng, and high pressure operation of the column. Degassing solvents preferable with an in line vacuum is highly recommended. Also, using a high pressure flow cell with post cell flow restriction will help to keep any residual gas in solution so there is no out gassing in the cell. This can be accomplished with a small piece of small ID tubing.加背压 * assware and solvents are clean when you start. If you are going to recycle, use a very large volume of solvent like 5 liters for standard bore columns and be willing to deal with this problem. An unequilibrated mobile and stationary phase system can also produce this drift, just consider the first example of a gradient. If you are operating in an isocratic mode, wait longer until you are equilibrated. Try cleaning the column with a series of solvents and gradients before you start equilibrating. This will help in achieving a more rapid equilibration. Contamination bleed in the system can also cause this drift, especially when using a gradient. The contamination may precipitate from solution at the beginning, and then redissolve at the end of the gradient. Start w/clean. * How many people have seen this? Peaks without a injection? We call these ghost peaks, and we usually see these in a blank gradient method. The problem is pronounced contamination in the mobile phase or the column. Once upon a time there was an environmental firm, new to HPLC, that was analyzing for PAHs. The gradient acetonitrile/water method looked like this baseline, even without the sample being injected. When asked about the quality of the acetonitrile and water, they responde