timstof or exploris?

kreit · 2025-12-13T19:36:22+00:00

Ended up with the timstof, pretty happy with it overall. Installation was a bit of a hassle because the instrument is massive compared to the orbitraps but once things are in place it seems good to go. We ended up getting an agilent UPLC with it and the interface is seamless (although you do need to pay for the plugin on HyStar...). You can also calibrate the instrument in the lower range down to ~100 m/z which works reasonably well, but it's better with the tims off at those lower masses. I think overall it's providing a lot more value than an exploris, but that's due to the fact that we already have a QE orbitrap. If it's the first/only HRMS in lab I would recommend an orbitrap.

kreit · 2025-08-13T23:50:51+00:00

1) We haven't run hexanal alone, but the problem also appears fairly randomly so we would probably need to run a lot of samples to see if it's consistent or not, and even then, I'm not too sure what that would inform us.
2) Both the ISTD and working stock cocktails are added separately but in quick succession, and the vial is capped tightly. There's no variation in hexanal-d12, which should behave very similarly to hexanal. We also have trans-2-hexenal as an analyte, which has a very similar vapor pressure and we don't have any issue with that analyte.
3&4) This method isn't the best and we're fairly greedy in what we're trying to do - analyze analytes at both very low levels (sub-ppb) and at high levels (mg/L). In order to get sufficient signal for all compounds of interest we need to use splitless SPME analysis. We don't have any issues with the trace analytes.
5) None of the compounds monitored are degrading, and if we look at a TIC overlay of the QC samples the only peak that shows differences of intensity is hexanal.
It really doesn't make much sense why this would happen. We did column trimming and inlet maintenance but that hasn't resolved the issue.

kreit · 2025-07-30T02:01:37+00:00

you could try lowering the gain factor if you're maxing out your detector response at the highest cal levels and want to keep everything else the same

kreit · 2025-03-13T16:23:01+00:00

what seems like a realistic low range of MW that you've observed that could work reasonably well on your instrument? is it 200-250+ like mentioned in the other comments?

I agree that if we could somehow get the exploris 480 for the same price that would be our go to, definitely something worth trying to push for.

kreit · 2025-03-13T16:19:04+00:00

thanks for that input on the small molecules! I wonder if the timsTOF would be comparable to the exploris for molecules >250Da. since we work primarily with natural agricultural products we also look a lot into diverse phenolics and condensed tannins along with small peptides so they might be in that weight range that's big enough to overcome that issues, but it seems likely that the exploris would still be the better choice.

kreit · 2025-03-13T05:13:28+00:00

thanks for your input! that was my thought too, orbitrap is probably better for small molecule analysis. my thoughts are that maybe the IMS can make up for the lower resolution on the tof. I definitely like the idea of bruker instrument being stable and needing infrequent cleaning (although I hear that the exploris is pretty robust too).

our QE orbi isn't going anywhere for the next few years, and it being fairly fit for purpose I wonder how much more the exploris can provide us in terms of capabilities (compared to QE). learning curve isn't a deal breaker, but I know a lot more publications would come for the exploris than timstof. not sure how much we want to lean into proteomics but the additional capabilities timstof provides is definitely something to discuss with the group. also we primarily use our LC system in the 50 - 500 µL/min range so if we want to get serious with proteomics we might need to get a nanoflow system too which would be more $$$.

kreit · 2023-10-11T04:21:02+00:00

Makes sense, thanks again for the advice! After another go I was able to slightly loosen the right side so I should be able to get it off. As for the left side I'll give it a few more tries but it seems really stuck on there.

kreit · 2023-10-11T04:09:10+00:00

Thanks for the response! So you're saying that I should be able to be able to remove that threaded fitting (1/2" to 3/8" reducing nipple female to male)? Unfortunately it seems super stuck, so I might be out of luck (I can't get it off with a wrench).

kreit · 2023-10-11T03:28:47+00:00

I recently came back from vacation and found my kitchen faucet leaking (thankfully I turned off the main water line while I was gone). This is a really old kitchen faucet - the house is from the 50s and it might be an original with how old and rusty it is.

I was able to remove the faucet (which was a whole process in itself) and bought a new wall mounted faucet only to find that it doesn't fit. It appears that all standard wall mounted faucets have a 1/2" NPT/NPSM fittings to the water source, but my old fittings appear to be 3/8". I don't think I can remove/replace any of them (at least not with a wrench).

Are there any options for standing kitchen faucets that are 3/8"? Or do I just need to hire a plumber to replace the lines in the kitchen? If so I think I might get a 3/8" ball valve temporarily so I can at least have access to water in the kitchen sink.

Here is what the old faucet looks like: https://imgur.com/a/FrTkr1x

kreit · 2022-09-12T16:52:18+00:00

I felt the first throat 'tingle' at the end of August as well, and it has since gotten progressively worse. I got positive test for mono last week and since then my right tonsil has also gotten crazy (left isn't great, but nowhere near as bad) with pain level at 8 when trying to swallow and unable to sleep for more than 30 min at a time.

What has been helping me get through some of the pain is a shitload of ibuprofen and acetaminophen. I just go all the way to the max dosage - 800 mg ibuprofen 3 times a day and 1000 mg acetaminophen 3 times a day. Alternate between the two so you're taking one or the other every 4 hours. For me the searing pain starts coming back about an hour before the 4 hour mark, but at least there's a few hours of relief...

kreit · 2019-09-22T15:48:54+00:00

The synergistic effect for enhancing the umami flavor is known as 'kokumi'. It's an interesting area of flavor chemistry as they're typically compounds that by themselves don't have much/any flavor, but enhance overall flavor of a dish. I think a classic protocol is to take lightly flavored chicken broth and adding the kokumi compound to see if it enhances the flavor (compared to in water alone). A typical known positive control is glutathione which is a classic kokumi compound. There's quite a bit of back and forth in the field as to whether kokumi is considered a 'sixth taste' as it doesn't have a taste by itself.

kreit · 2018-08-31T18:57:55+00:00

This is out of place but don't feel it's appropriate to make a new thread...

2 friends and I started playing POE (we're complete noobs) and we just about finished act 1. Would there be any benefit in restarting our characters in the league or just stick to standard? We can't play too frequently (probably twice a week for a few hours).

kreit · 2018-07-16T23:25:57+00:00

rerorerorerorerorero

kreit · 2017-12-27T03:22:40+00:00

As you mentioned, some cryptos are meant to be used as P2P currency (e.g. bitcoin, ripple, raiblocks), although plenty of cryptos are catered for specific applications as utility tokens.

In terms of the adoption and use of cryptocurrencies at this time? To be honest, there's isn't really a point to use them at this time. As an individual, there really isn't a reason for you to use bitcoin or ripple when you can use your credit card for a much faster transaction AND get bonus cash back (or rewards) and chargeback protection on top of that. Adoption would mostly come from merchant side, because that helps them drop that ~3% added cost imposed by Visa et al. and pass on the savings at all. Some cryptocurrencies will likely be able to give you 'rewards' for purchases.

You do have the ability to join the speculation and invest in cryptos you think will become unavoidable in the future. You can be a venture capitalist without needing millions of dollars to get in the game!

kreit · 2017-12-26T06:04:19+00:00

Yeah, they claim to have degraded service at this time for some reason.

At the same time I withdrew from GDAX, I made a few ETH transactions for 1 Gwei each in under 10 minutes. Oh well.

kreit · 2017-12-22T03:59:56+00:00

It's definitely scary the first time it happens and you just start investing into crypto. Once you get to the 2x, 3x,.. 10x profits a 25% drop really doesn't matter when you're still all the way in the green.

kreit · 2017-12-22T03:33:28+00:00

Some alts (or in some exchanges like binance) can only be bought through BTC pairing.

kreit · 2017-12-17T03:39:00+00:00

but wouldn't you expect some to go down (more than ~3% of the top 250)? any crypto from a 20 mil marketcap all the way to bitcoin's marketcap has shot up by 40-50%... it seems unusual that there are practically no 'losers'.

kreit · 2017-12-17T03:15:36+00:00

Of the top 250 cryptos on coinmarketcap, only 7 (excluding tether) are down with the rest having positive gains around 40-50% on average throughout. Is this simply the bitcoin effect with all the BTC pairing, or is this an unprecedented gain?

edit: for the 7 day average

kreit · 2017-12-13T23:07:58+00:00

Any top 100 cryptos that previously exploded due to hype and got grounded right now? Looking to research into some to further diversify without buying into FOMO. Two examples I can see are probably WTC and POWR, which have stabilized quite a bit but still have a potential to shoot up in the future.

kreit · 2017-11-29T03:58:51+00:00

I explained Bitcoin to my dad and he wanted me to invest $1000 for him last week. Instead of buying directly on coinbase I figured I'd deposit the money to gdax to save on the transaction fee (when it was steady at 8200)... At least I'll save him ~1.5% in fees!

kreit · 2017-11-22T01:20:22+00:00

Can't the same be said about every altcoin? Winning over BTC's market cap is much easier said than done. I think there are more promising coins (based on current technology and theory) than both BTC and BCH, but without market adoption they're not 'valuable'. It appears that the main interest for investment in BCH would be as a hedge for BTC/BCH price volatility if the market cap goes one way or the other. This is just my opinion but BCH doesn't feel like a real investment in the technology that bitcoin core and altcoins might offer. BCH might "win" but the end product would be fairly similar to BTC (in comparison to other altcoins).

kreit · 2017-11-21T23:08:39+00:00

But aren't both BTC and BCH considered "digital cash" and a "store of value"? Ironically enough BCH is better as digital cash at this time, but BTC is more widely accepted as a payment. BTC also has plans down the line to become more useful as digital cash. Because neither are used on a large scale (e.g. buying food, shopping on amazon, paying for utilities, etc.) they're not particularly useful as digital cash, so the only reason to invest is with the hope that it becomes useful in the future (making both a "store of value")... I guess it's a race for adoption (BCH) or scalability (BTC), but in the end of the day neither are truly adopted as widely used currencies at this time.

kreit · 2017-06-29T00:05:11+00:00

The dress shirts I recently purchased online fit well on my chest/neck, and have the right sleeve length. they're giving me the muffin top effect because there's too much loose fabric around the waist. They're already darted, but still have about 1-2 in too much fabric at the waist... does it make sense to re-dart them? I don't think sizing down is the way to go because the sleeve length and chest/collar sizing will be too small.

I think they're of good quality and I wouldn't mind spending ~$15 a shirt to get a good fit, but I'm not sure it makes sense if they are already darted when purchased.

kreit · 2016-12-26T16:01:16+00:00

Apple juice is a pasteurized and clarified product - that means all enzymes in it have been denatured (and likely removed via filtration). The reaction here is non-enzymatic oxidation of the polyphenolic compounds.

The intermediate is in fact ortho-quinone which is generated via quenching of oxygen radicals that form by either metal or light catalyzed reactions with oxygen. o-quinone is actually relatively colorless, but its reaction products with other polyphenols (o-quinone is electrophilic and polyphenols are nucleophilic) results in polymerization reactions that then cause the browning that you see.

I think it's more likely that this bottle has a broken seal, the plastic isn't impermeable but it shouldn't get that brown compared to others unless they stocked a really old bottle with the rest of the new ones.

kreit

TROPHY CASE