【求助】基线 Waters LC 1525 Pump, 2478 UV Detector, thanks

UV灯是有寿命的,一般使用时间长了,在低波长段是很不稳定的,特别是在做梯度洗脱的时候.

ciaclin 发表:Sorry, Can not type Chinese in office.

Now I had technical question on the Waters $$lc ( 1525 Pump, 2478 UV detector)

When I apply gradient solvent on the assay, got some confusion: the baseline @ 205,208, 210 always drift to a high value, the Uv Absorbance reading increased a lots.

However, the baseline @ 260, 278, 340 nm is working 100% well.

Is there any problem at Uv lamp? Or that energy deteriorate or loss?

Thanks for you reply.

--------------------------------------------
最近清理实验室, 想最后评估以下老的Waters $$lc 1525 Pump, 2478 UV Detector. （实在对他很有感情了， 5年了 ， 象老黄牛一样任劳任怨）

使用梯度淋洗， 老是在低波长的时候， 吸收突然增高，基线升高很大。
Min A:H2O, B( ACN)
0 85 15
15 30 70
20 30 70
25 85 15

只要是gradient elute, 就在低波长的地方出现以下情况。
相同的gradient elute 在 1100， 1200 上面，基线很平稳, 一点问题都没有。

是Uv lamp 老化了，？ 能量降低？
请各位$$lc 专家帮忙看看原因， 谢谢。

以上文本借助

Thank you ……

Hello ciaclin,this problem maybe UV lamp overlife,or flow cell dirty, also your optics unit need change.

You could change UV lamp first, and then pick off flow observe the baseline.

Update:

Just replace a NEW Uv lamp and change the flow cell.

When use the isocratic, get a decent baseline @ 205, 210, 220, 279 nm
However, after changing back to gradient, the baseline @ 205,210, 220 nm is a crap.

Any comments would be highly appreciated.

这是正常的

2487波长范围是190nm—650nm