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- Posts: 1
- Joined: Thu Feb 02, 2023 5:52 am
- Location: South Korea
I'm using a Shimadzu SPD-M40 Diode Array Detector. Scan range 190-500 nm. I focused on 210 and 307 nm for compounds of interest. Mobile phase are 0.1% formic acid in water and acetonitrile with 0.1% formic acid gradient increase % acetonitrile throughout run.
I already read a previous question who used a Shimadzu SPD-M20A. My main point is what is the relationship between UV cut-off and baseline drift. I compared
0.1% formic acid and acetic acid the wavelength from 210 nm to 250 nm. The result was that UV 230 nm of acetic acid (water and MeCN) and UV 240 nm of formic acid have same drifting baseline.
Also, there is no leak and Cell temperature is same as column temperature (40 C). My eclipse C18 column is good condition.
And I checked the UV cut-off of methanol (210 nm) and MeCN (190 nm) in my device. So, I don't understand UV cut-off of formic acid in my device.