Column problems and solutions

First, the phenomenon: the spectrum, the ion peak is very close, the separation is low, the lack of spectrum in the sample contains ions and peak peak time shorter.
Possible cause: aging of the separation column results in a decrease in column efficiency.
Solution: 1 adjust the eluent proportion and concentration, and appropriate to reduce the flow rate
2 change the separation column
Second, the phenomenon: the column out of the peak deformation, resulting in forward or tail and flat peak situation
Reason: 1 sample concentration is too high, beyond the column capacity
2 column effect down, the exchange is not complete
Solution: 1 sample the appropriate dilution after sample analysis
2 Replace the column