Polar Compounds using UPLC BEH Shield RP18 Column in Highly Aqueous Mobile Phases

sazimi

<p>Dear UPLC friends</p><p style="height: 8pt"/><p>Recent developments in reversed-phase column chemistry resolved all types LC analysis & separation, but main thing for user & researcher is to understand the engineering behind the columns after that they can develop a mobile phase. Like UPLC BEH Shield RP18, YMC AQ, Synergy Hydro-RP, Pinnacle IBD, Ascentis Express RP-Amide, Zorbax Bonus-RP ..... etc. all are specially engineered columns</p><p style="height: 8pt"/><p>I am here to discuss & share my UPLC experience of UPLC BEH Shield RP18 column a polar embedded carbamate group column.... best column in UPLC for Highly Aqueous Mobile Phase analysis & best for seperation for polar compounds like phenolic analytes.</p><p style="height: 8pt"/><p>If anyone have used UPLC BEH Shield RP18 for analysis of polar compounds in High Aqueous Mobile Phases they can share their experience on this topic, because High Aqueous Mobile Phases are good for green chemistry & it is cost effective & no doubt best seperation.</p><p style="height: 8pt"/><p>I just want to share my experience & knowledge on this portal, because at this presentation peoples were so limited & remember all application in this was developed in our lab on our UPLCs.</p><p style="height: 8pt"/><p>Thanks.</p><p style="height: 8pt"/><p>Salman Azimi</p><p>Analytical Specialist</p><p>Drug Quality Control Lab - Qatar </p>

dougm

Hello,

Thank you for sharing your information with us. However, I would like to point out that in our years of polar compound/column testing at Waters, embedded polar group columns actually provide LESS retention for polar analytes than properly designed reversed-phase straight alkyl chain C18 chemistries such as Atlantis dC18, Atlantis T3 and HSS T3 columns. All of these C18 chemistries were designed to resist dewetting under high aqueous conditions after a loss of pressure (promotes dewetting - see attached). For example, we QC test our T3 chemistries using 100% aqueous mobile phases on very polar analytes such as adenine, thymine, etc. Have you tried the HSS T3 chemistry yet? You showed a slide mentioning it.

I've attached an older presentation. Please review at your convenience. Embedded polar group columns ARE aqueous compatible, but according to our test results, that is where their polar compound retention usability ends. They can provide alternate selectivities vs staight alkyl chain C18 columns, especially for analytes with structures containing multiple aromatic rings. They also exhibit very good peak shape for basic compounds. However, if you are struggling to retain polar compounds using a conventional, high coverage, fully endcapped C18 column, I would not recommend an embedded polar group column. Rather, I would recommend a T3 chemistry or I would recommend HILIC as an analytical technique using a column such as Atlantis HILIC Silica, XBridge HILIC, ACQUITY UPLC BEH HILIC or BEH Amide chemistry.

Thanks for bringing this topic up. We've done a lot of work in this area.

--Doug

sazimi

Dear Doug

Thanks for your valuable comments, my concern on this topic not for comparing who is the best BEH Shield or HSS T3, my task was choosing Polar Embedded columns in high aqueous phases for polar analytes, this thing raised when we got a sample required USP=L60 column & it is alkyl Amide phase column (e.g. Supelco ABZ, Zorbax Bonus-RP etc.) & in our law we must follow the manufacturer data files, or USP, BP & EP… otherwise give some justification & provide validation data if we used any other columns & this always prolong the analysis & you know Waters don’t have USP=L60 so at that time I suggest to use Waters Shield column (alkyl carbamate phase), which is USP=L1 but very similar to alkyl amide, bcuz both are Polar-Embedded Alkyl Phase columns so justification for Shield becomes easy for us.

I know very well about HSS T3 column I am using with alkaloids & it is very popular for LC-MSMS now.

No doubt especially for polar compounds HSS T3 should be the first choice, but I got good application experience with polar embedded group columns with basic, acidic as well as neutral & non-polar compounds.

Some researcher also claiming RP-Amide columns are universal column & this was true when I assist to my friend in Pharma Company to developed eight different samples method by 1 column (Ascentis Express RP-Amide, 2.1x75,2.7u), before they were on HPLC & their four methods on C18, two on C8, one on Cyano & one on Phenyl columns. Now they are on UPLC & using just one column for eight products.

Dear Doug thanks for your HSS T3 seminar.pdf (I already have this), this is the reality that all manufacturer claiming that their columns are the best, but my thinking that all columns are good but you must have extensive knowledge on all types of columns that exactly where to use for best results.

I will also send you one of my applications of UPLC BEH Shield; it proved that Shield doesn’t need ion-pairing reagents for best peaks. May be UPLC HSS T3 do so but I never tried.

Best Regards

Salman Azimi

wildcat

Dear Azimi

You both posted an interesting topic, i am in method transfer/development team and we are working to transfer/develop our two methods in highly aqueous mobile phase, but still i am little confused that i have to use either UPLC BEH Shield or UPLC HSS T3? Because these two HPLC methods are on Supelco ABZ+ & 65-75% aqueous in mobile. My samples are combination of 3-analytes & 2-analytes & details are

Sample #1 two neutral compounds & one polar

Sample #2 two polar but large in molecules (400-600 mw)

I also request Waters co-workers to sugest me which column is good for these two samples, i read HSS T3 is best for polar but not recommended for large molecules like 400-600 mw.

Mr. Azimi, i was reviewing your paper posted in this thread, polar embedded alkyl group columns are Supelco ABZ+ as well BEH Shield, according to this paper i can use Shield column for my samples?

I hope i will get satisfactory answer from Waters.

Thanks.

Sophia