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Thread: how do you measure thc?

  1. #16
    420 Member Medical Marijuana's Avatar
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    Re: how do you measure thc?

    Yes, you can get accurate concentrations of THC.
    Take this abstract from a paper prepared for the Dutch Government.

    Strong increase in total delta-THC in cannabis preparations sold in Dutch coffee shops

    * FTA Pijlman11Trimbos Institute for Mental Health and Addiction, PO Box 725, 3500, AS Utrecht,The Netherlands,
    * SM Rigter11Trimbos Institute for Mental Health and Addiction, PO Box 725, 3500, AS Utrecht,The Netherlands,
    * J Hoek22DeltaLab, Albrandswaardsedijk 74, 3172 AA Poortugaal, The Netherlands,
    * HMJ Goldschmidt22DeltaLab, Albrandswaardsedijk 74, 3172 AA Poortugaal, The Netherlands &
    * RJM Niesink11Trimbos Institute for Mental Health and Addiction, PO Box 725, 3500, AS Utrecht,The Netherlands

    *
    1Trimbos Institute for Mental Health and Addiction, PO Box 725, 3500, AS Utrecht,The Netherlands 2DeltaLab, Albrandswaardsedijk 74, 3172 AA Poortugaal, The Netherlands

    Correspondence to: Dr. Femke Pijlman, Trimbos Institute for Mental Health and Addiction, PO Box 725, 3500 AS Utrecht, The Netherlands. Tel: +31 30 2971100. Fax: +31 30 2971111. E-mail: fpijlman@trimbos.nl.

    The total concentration of THC has been monitored in cannabis preparations sold in Dutch coffee shops since 1999. This annual monitoring was issued by the Ministry of Health after reports of increased potency. The level of the main psychoactive compound, Δ 9 -tetrahydrocannabinol (THC), is measured in marijuana and hashish. A comparison is made between imported and Dutch preparations, and between seasons. Samples of cannabis preparations from randomly selected coffee shops were analyzed using gas chromatography (GC-FID) for THC, CBD and CBN. In 2004, the average THC level of Dutch home-grown marijuana (Nederwiet) (20.4% THC) was significantly higher than that of imported marijuana (7.0% THC). Hashish derived from Dutch marijuana (Nederhasj) contained 39.3% THC in 2004, compared with 18.2% THC in imported hashish. The average THC percentage of Dutch marijuana, Dutch hashish and imported hashish was significantly higher than in previous years. It nearly doubled over 5 years. During this period, the THC percentage in imported marijuana remained unchanged. A higher price had to be paid for cannabis with higher levels of THC. Whether the increase in THC levels causes increased health risks for users can only be concluded when more data are available on adjusted patterns of use, abuse liability, bioavailability and levels of THC in the brain.

    Addiction Biology

    Volume 10 Issue 2 Page 171-180, June 2005

    To cite this article: FTA Pijlman, SM Rigter, J Hoek, HMJ Goldschmidt, RJM Niesink (2005)
    Strong increase in total delta-THC in cannabis preparations sold in Dutch coffee shops
    Addiction Biology 10 (2), 171–180.
    doi:10.1080/13556210500123217

  2. #17
    420 Member Medical Marijuana's Avatar
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    Re: how do you measure thc?

    And go here if you want to know about gas chromatography Varian GC-FID

    Application Note Categories
    GC/FID

    In GC/FID, the FID or flame ionization detector detects analytes by measuring an electrical current generated by electrons from burning carbon particles in the sample.

    The flame ionization detector (FID) is a non-selective detector used in conjunction with gas chromatography. Because it is non-selective, there is a potential for many non-target compounds present in samples to interfere with this analysis and for poor resolution especially in complex samples. The FID works by directing the gas phase output from the column into a hydrogen flame. A voltage of 100-200V is applied between the flame and an electrode located away from the flame. The increased current due to electrons emitted by burning carbon particles is then measured. Although the signal current is very small (the ionization efficiency is only 0.0015&#37 the noise level is also very small (<10-13 amp) and with a well-optimized system, sensitivities of 5 x 10-12 g/ml for n-heptane at a signal/noise ratio of 2 can be easily realized. Except for a very few organic compounds (e.g. carbon monoxide, etc.) the FID detects all carbon containing compounds. The detector also has an extremely wide linear dynamic range that extends over, at least five orders of magnitude with a response index between 0.98-1.02.
    Last edited by Medical Marijuana; 12-14-2007 at 11:09 PM.

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    Re: how do you measure thc?

    ya but my point is you average joe being able to do it , can you afford to buy all that equipment just to find out how powerful you weed is?or even know anyone in your area that can do that ???

  4. #19
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    Re: how do you measure thc?

    I guess it comes down to subjectivity V objectivity.

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    Re: how do you measure thc?

    or as i say "same shit different pile "

  6. #21
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    Re: how do you measure thc?

    I have the Cannalyse at home. Already for 6 months actually and did not use it yet. To be honest: it's not completely clear to me how to use it. There is a manual in there, but still it leaves some questions.

    It's not really meant for consumers like us, more for coffeeshopowners who want to know what they're selling. When they buy this from the wholesaler they can get a whole day of 'explaining the kit' by the wholesaler...

    I need to put some time in this. It's very interesting. And I think pretty accurate (that's what I heard)...

  7. #22
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    Re: how do you measure thc?

    Cannalyse was gone for 60sec., but its back!
    Same quality product, with a diverent name..CANNALYTICS

    grtz & take care..
    It's all about cannabis and it always will be!!
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  8. #23
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    Re: how do you measure thc?

    I came on this which is a good read on the topic.

    Medical Cannabis Potency Testing Project

    Dale Gieringer, Ph.D.
    California NORML, 2215-R Market St. Suite 278
    San Francisco CA 94114 tel: (415) 563-5858
    E-mail: canorml@igc.apc.org

    Given the rapidly growing use of medical cannabis for a wide variety of indications and the manifold different underground sources currently supplying patients, there is a natural interest in investigating the potency, purity, and chemical content of the available supplies of medical cannabis. While the availability of medical cannabis has increased in the wake of the passage of California's Proposition 215 and other state medical marijuana initiatives, scientific research on its content remains frustrated by the continued federal ban on medical cannabis research.

    In an effort to cast light in this obscure area, a research project was undertaken by a group of us, including researchers, growers, and medical cannabis buyers' clubs, with support from California NORML and MAPS, to analyze samples of medical cannabis from various patients' cooperatives and providers around the country. This effort proved to be a lesson in the difficulties and uncertainties of cannabis research in a society where freedom of pharmacological research has been stifled by an effectively totalitarian drug bureaucracy.

    From the outset, our project was frustrated by a lack of access to qualified research labs with expertise in analysis of cannabis. The leading research lab in the country declined to do business with us for fear of compromising government contracts, while the other likely candidates were all foreign and thus not legally accessible to us because of DEA regulations. In the end, we were fortunate to obtain the services of a laboratory that had the requisite DEA license and equipment (a gas chromatograph mass spectrometer, or GCMS), but no prior experience in cannabis analysisin fact, its primary business was drug urinalysis! The analysis of our samples was accordingly a learning process for both the lab and ourselves.

    Our original aim had been to obtain a broad-spectrum quantitative analysis of as many of the 60-plus naturally occurring cannabinoids as possible, in the hope of detecting differences that might produce differing therapeutic effects among the samples. To our disappointment, however, our lab could obtain laboratory standards only for the three most common cannabinoids, delta-9-THC, cannabidiol (CBD), and cannabinol (CBN).

    A total of 47 different samples of medical cannabis were submitted by over a half dozen different providers and patients' cooperatives ranging from California to the East Coast. Included were 42 samples of sinsemilla bud, three samples of hashish or resin; one liquid sample of a milk-based cannabis drink ("Mother's Milk"), and one capsule of an oral whole leaf preparation.

    Upon analysis by GCMS, the potency of the 42 sinsemilla samples was determined to range from 10.2&#37; to 31.6% THC, with a mean of 19.4%. These results were surprisingly high, given that the average potency of marijuana in the U.S. has been typically estimated at around 3% to 4% by NIDA, with higher grade sinsemilla ranging towards 10% - 15%. The highest potency recorded came from a sample of hashish, which registered 68.6%. Yet even a sample of Mexican commercial grade registered a surprisingly high 11%, twice what we had expected. All of this cast a troubling shadow of doubt on our test results, although it appeared likely that we were dealing with highly potent varieties.

    In contrast, the CBD levels observed were surprisingly low. Only four of the sinsemilla samples had more than 0.3% CBD, and 35 of them had only trace amounts (<0.1%). However, one sample had an astoundingly high CBD content of 28.0% (plus 11.6% THC). Another registered 5.6% CBD and 13.4% THC. Aside from these two anomalies, the CBD results were frankly disappointing, as we had hoped to discover significant variations in the content of the samples, with accompanying variations in medical activity. Because CBD is suspected to have peculiar efficacy for control of muscle spasms and for damping anxiety and "panic reactions" caused by THC, we had hypothesized that certain patients would tend to prefer high-CBD varieties. In fact, however, it appears that few patients are ever exposed to high-CBD cannabis. Unfortunately, we were unable to procure additional specimens of the high-CBD varieties for further testing.

    As for CBN, the majority of samples showed only trace amounts. The highest level detected was 1.4%, and only one other sample tested above 1%. CBN is a breakdown product of THC, so high CBN levels are expected in old, degraded samples. This was confirmed by the fact that one of the samples above 1% CBN was known to be a year old. The prevalence of low CBN in the samples was evidence that most available medical cannabis tends to be fresh and well-preserved. Otherwise, these results were of limited interest, as there are few if any known medical effects of CBN.

    Another disappointing surprise was the failure to detect more than trace levels of THC or CBD in the liquid "Mother's Milk" sample. Upon further investigation, the lab determined that this was because it is impossible to extract cannabinoids from fat-based liquids using standard methanol extraction techniques. Consulting with other researchers, we found that there is no known method for isolating THC from fat-based liquids.

    Later, we located a lab that claimed to have developed a secret, proprietary method for extracting cannabinoids from fat. With considerable difficulty, we arranged to have the lab test the Mother's Milk. To our disappointment, however, once again only trace amounts of THC and CBD were detected. Just to make sure, one of us swallowed a sample of the Mother's Milk (which by now had spent several months in the freezer) and found it to be delightfully potent. Evidently, the lab's technique had failed. It appears that further advances in testing technology will be needed in order to properly analyze fat-based oral cannabis products such as Mother's milk, bhang, ghee, and possibly baked goods such as brownies.

  9. #24
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    Re: how do you measure thc?

    bump

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  11. #26
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    Re: how do you measure thc?

    Cannalytics Test Kit is a Cannabinol test(mini lab) that is in full compliance with the guidelines of the World Health Organization concerning the safety and quality of medicinal plant materials. (WHO/PHARM/92.559).
    The method meets the guidelines and recommendations of the Food and Agriculture Organization (WHO) Codex Alimentarius.
    The Cannalytics Test Kit is already validated at the University of Leiden (department of pharmacognosie). Research is still going on with focus on speed and the safety aspects.

    its even posseble to extract cannabinoids from fat with the Cannalytics cannabinoid test kit.
    It's all about cannabis and it always will be!!
    http://www.regularmagazine.nl
    http://www.regularmagazine.eu
    http://www.facebook.nl/Regular.magazine

    Regular magazine, thé magazine for the global cannabis subcultures, read it, sub us & thump up for Regular magazine

  12. #27
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    Re: how do you measure thc?

    ^This is a good tester for THC, and cost effective. If you do not have a specific need for a full cannabinoid profile, I recommend it.

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