I believe “4A will remove water, but not propane from your benzene” is the correct interpretation.
If three carbons in a line is too big for the 4angstrom pores, then six carbons in a ring will also not fit.
Kinetic diameter - Wikipedia lists the relative “sizes” of those two.
Using the same lab we have used for the last 5 years for testing. Its only showing up in HTE from jar tech diamonds or cold crashing and separating. Does seem our whipping process for budders gets it to below the 1ppm fail but its still showing up. The Hte is run through a roto vap to remove residual butane to ND but still popping for 3ppm of benzene.
When we made the switch to SD we were told we were getting the highest grade of butane possible. Didnt know you sold lower quality gas.
Inthink they were the tanks with the blue logo. I’ll confirm in the am.
Why is better 99.9% and best 99.7%?? Chili p?
But what if the 99.9% is in a dirty mug?? Would you want 99.7% in a clean mug? Or 99.9% in a dirty mug??
We know how the owner feels…… 
Run your gas through activated carbon as a vapor before compressing…
Activated carbon can selectively absorb benzene from butane, propane, & isobutane.
https://www.sciencedirect.com/science/article/abs/pii/S1383586615303725
Benzene, Toluene, Ethylbenzene, and Xylene removal:
Edit:
If your system is contaminated with water solubles / heavy metals / pesticides / things that follow HTE: The only thing I have found to be able to really clean it out (and pass chemical testing) is Acetone then Hot Water.
You may need to re-zero some zones before using the AC filter. Though, AC typically catches all of the potential problems.
We can supply an AC filter in a 350psi housing if needed. Working on getting the webpage updated with all of our filter options.
Lex got caught in a lie on a gas panel back on November 8th. The lie that they “clean every cylinder before every refill”. They were called out on this lie by - what seems to be - one of their own gas suppliers. They then conveniently started to offer various grades of gas on November 19th… one of those grades being cylinders that they actually do not clean before every refill. Solvent Direct is so much smoke and mirrors and bullshit that even their own vendors are sick of them. I bet they haven’t been “cleaning every tank” for awhile, and when they were called out on it they claimed that they were just now offering this option.
You can watch this lie be exposed here between 1:36:40 - 1:37:10
Also… it is a bit weird that the actual best gas on that list is not offered in a “cleaned” tank… hmmmm… dirtying that clean coffee I see
You could always do GC-TCD-FID…
Since no two molecules/atoms have the same thermal conductance - “The TCD will adequately measure down to the 0.01% level.”, the TCD essentially makes the GC into an MS. But you have to derivatize acidic or other temperature sensitive molecules.
OR even GC-TCD-PID-FID ? Since PID is ppB and FID is ppM, would add a layer.
I’ve always been a bit confused by the dirty mug concept. If these tanks are carbon steel then it seems to me the dirt is coming from the mug itself. There’s a reason stainless steel is the standard for food and pharmaceuticals, carbon steel is fine for gases but anything liquefied needs to be ss if it’s food grade.
It’s not like this explains anything involving benzene or Medusa, but the material container basically limits the grade of this to industrial grade IMO and that’s how it should be treated when it comes to your facility
I also understand suppliers not switching to stainless, big investment in infrastructure (though we’d ultimately pay for it), but I don’t think those carbon steel vessels have a 3a surface finish so 
Multiple detectors doesn’t necessarily trend in the direction of simpler or less expensive. TCD isn’t really adding any resolution FID doesn’t already have.
Thanks for the tips. Would love to grab a filter.
I would agree but then the gas companies would need their bulk tanks to also be stainless as @Dukejohnson got plenty of brand new gas in brand new stainless vessels that failed for benzene. It doesn’t seem to matter if the tanks are carbon steel or stainless if the bulk that goes in is contaminated.
Agreed. It does seem to point out a lack of attention to detail (or lack of care) when it comes to quality control. Again, (and as others have said), quarantine it until you’ve done your own QC and this becomes less of an issue.
No one seems to be able to test the bulk butane in tanks for us. Our labs that we test through said they can’t do it. We found some random non cannabis one in Bakersfield that could do it but won’t come out on site and have 2-3 week turnaround plus about 200$ per tank in testing cost not including the gas to drive it out there.
This would make us need to have 60+ tanks in quarantine to make sure we had enough gas to get though during subsequent tests. We can’t have that many tanks on site.
I’m open to any ideas others have tho and I appreciate the help.
Anyone going to try the gas kit SD posted?
Also when running vapor through AC what size micron needs to be used to filter?
We offer stainless steel cylinders. Our clients love them. We’ve even had clients lock in contracts based partly on the fact that they were using them. During a walk through of your facility with a potential partner the stainless steel cylinders really set you apart from everyone else.
Amspec is who we use for independent 3rd party. They only do the LP testing in Houston. The Sensidyne 1ppm Benzene kit should be arriving Tuesday to your facility.
Forgive me for the length of this reply, but I care about this deeply. I would like to invite everyone here to video conference to talk about these issues and concerns together tomorrow face to face. If you aren’t willing identify yourself on camera and want to hide behind fake accounts, don’t bother. You will be removed from the meeting.
Gas Quality Meeting
Saturday, March 16 · 12:00 – 1:00pm
Time zone: America/Chicago
Google Meet joining info=
Video call link: https://meet.google.com/ajg-kucb-gag
Or dial: (US) +1 240-514-8460 PIN: 628 482 334#
More phone numbers: https://tel.meet/ajg-kucb-gag?pin=7647434453424
The reality is, we maintained an exclusive contract with a single vendor who diligently cleaned each cylinder before every refill for many years. This vendor meticulously documented the cleaning process, providing certifications of decontamination with dates and serial numbers. We remain committed to this practice, with all certification details readily accessible in real-time at www.solventdirect.com/compliance.
However, the hash fight video meeting was a significant turning point. If vendors that want us to distribute for them are going to discredit us publicly and after nearly a decade of advocating for higher standards amidst competitors selling “clean” gas in cylinders that were refilled without cleaning, enduring numerous attacks on our integrity and baseless accusations regarding our cleaning practices, we reached a breaking point.
Following the hash fight meeting, we opted to diversify our gas sources by procuring from multiple vendors who had long sought our partnership. This move allows us to source from vendors more geographically and logistically efficient, reducing turn times and cost. We pass these savings on to our clients.
Consequently, on 11/19/23, we introduced our new gas options to strike a balance between quality and value. Instead of selling only one vendor’s gas, we now offer options from every vendor in the US. We now distribute every type of gas, but with the SD service and value extractors have come to expect from us. For instance, “perseus” gas is really just Cortera product and we sell the same exact product to ensure our clients have these options with the same great service at the lowest price possible. No gimmicks, just transparency in supply. Read more here: https://www.solventdirect.com/post/new-high-purity-extraction-gas-options-from-solvent-direct
Despite the considerable added logistical cost and time required to uphold cylinder cleaning protocols, competitors that previously called cylinder cleaning snake oil, now advertise cylinder cleanings. Consequently, shortly after the 11/8/23 hash fight video, we started distributing these new options. Just like we offer variations of alcohol such as 200, 190, CDA 12A (710), IPA etc, we now offer different variations of gas.
Simultaneously, substantial progress has been made with our efforts at ASTM to develop a new specification for gas specifically used in extraction. We are working with everyone from Airgas, Gas Innovations, QEG Diversified and Cortera along with agenicies, our scholarship recipients and institutions to finally write much needed standards for extraction supply in ASTM D37 03&04, a goal we’ve always prioritized. This effort has significantly leveled the playing field, and we’re on the brink of publishing this new standard following our upcoming meeting next week.
Furthermore, in recent years, several advancements have emerged in bulk high purity facilities, purification techniques, and cylinder cleaning methods tailored for extraction purposes. @eyeworm all of our chemical and gas vendors utilize their own GC’s and perform regular quality control testing along the supply chain per our vendor requirements. Cortera, led by Rami Rodriguez who developed the innovative Medusa filtration system, has his own GC, spot checks every tanker and performs a butane rinse (in depth video tour launching soon).
Additionally we work with other vendors like Specialty and QEG, using new techniques such as dry abrasion cleaning and BTEX filtration. We continue to see new bulk facilities popping up nationwide and we will continue to audit them like any other vendor when they reach out asking us to distribute their product. Our aim is to make the best extraction supply options accessible to all, recognizing that while many extractors prioritize affordability, we continue to serve quality-conscious clients who demand nothing but the best.
Ultimately, we are just a distributor and we are committed to providing exceptional service, efficient logistics, and unparalleled purity standards in extraction supply. We focus solely on serving the extraction sector, avoiding distractions from other industries, and offering aggregated buying power, reduced administrative overhead, and logistical efficiency to our clients across the US.
While our previous efforts centered on making safe gas accessible through a single vendor, the landscape has evolved, with several vendors now offering quality control measures, chain of custody transparency, and regular cylinder decontamination. We advocate for similar standards in gas supply, hence our working relationship with most high purity gas vendors in the US and abroad.
@johnbigoilco, I have been waiting all week for your team to provide the serial numbers for verification of the cylinders, but I haven’t seen anything come through. I will personally travel to you if it would help and you can easily search your certifications on our live repository at www.solventdirect.com/compliance.
I am also looking forward to requested additional information regarding the laboratory that conducted your extract analysis to confirm whether it was a vapor headspace capture. Given benzene’s volatility and the methodology’s dependency on temperature, calibration, and other factors, verifying these details is crucial.
We utilize Amspec in Houston for independent 3rd party testing and can facilitate introductions if needed, but we’ve shipped the Sensidyne Pump Kit at our own expense and this kit is capable of testing down to 1ppm benzene.
Quality remains our utmost priority. We will continue to distribute products from various vendors to ensure all options are available to Solvent Direct clients at competitive prices. The certifications, purity specifications and vendor information will always be available to our clients. If one of our vendors has a contamination issue, I will personally do everything in my power to fight for you.
