ABSTRACT
Lignin is a common and abundant byproduct of the pulp and paper industry and is generally burned to produce steam. Opportunities exist to acquire greater value from lignin by leveraging the properties of this highly conjugated biomacromolecule for applications in UV absorption and polymer reinforcement. These applications can be commercialized by producing value-added lignin nanoparticles (LNPs) using a scalable sonochemical process. In the present research, monodisperse LNPs have been synthesized by subjecting aqueous dispersions of alkali lignin to acoustic irradiation. The resulting particle size distribution and colloidal stability, as determined by dynamic light scattering, transmission electron microscopy and zeta potential analysis, of LNPs can be adjusted by varying the solution pH and ultrasonication energy. As-synthesized LNPs with a mean diameter of 204 nm were incorporated into poly (vinyl) alcohol (PVA) to prepare thin and flexible nanocomposite films using a simple solvent casting method. The addition of 2.5 wt% LNP increased the material's Sun Protection Factor up to 26 compared to 0 for neat PVA, while maintaining light transmission above 75 % in the visible spectra. In addition, the tensile strength and elastic modulus of the PVA nanocomposites improved by 47 % and 36 %, respectively. The presence of LNP also enhanced the thermal stability of the materials. Significantly, the proposed sonochemical process may be generally applicable to the synthesis of a range of naturally-derived LNPs for a variety of value-added applications.
Subject(s)
Lignin , Nanoparticles , Lignin/chemistry , Polyvinyl Alcohol/chemistry , Water , Steam , Ethanol , Nanoparticles/chemistryABSTRACT
Roadside vegetated filters strips (VFSs) reduce roadway runoff pollution by intercepting stormwater and reducing pollutant loads. VFS maintenance and operating costs can be reduced by designing the VFSs to serve as sites for production of marketable biomass. This biomass can provide feedstock for the emerging bioeconomy producing renewable fuels and biobased chemicals and products. Economic evaluation is needed to quantify the benefit of combining VFS with bioenergy biomass production. This evaluation requires a place-based approach to quantify availability of land, transportation costs, and benefits to sensitive habitats. We evaluated roadside land, within the state right-of-way, in Western Washington, to determine the total area available for implementing VFSs. These data were then used to estimate the volume and cost, of biomass produced on the filter strips, and the resultant reduction in pollutants emitted through highway runoff. The analysis showed that up to 5600 ha were available for roadside VFSs that would be within transportation distance of the theoretical biorefinery location. This space could produce up to 97 dry Gg per year of poplar biomass. The resulting reduction in biorefinery feedstock cost was up to $24 per dry Mg compared to biomass from dedicated tree farms. The results showed that combining roadside poplar with traditional dedicated poplar feedstocks can reduce the feedstock cost of the biorefinery from $76 to $67 per Mg for a biorefinery processing 150 Gg biomass per year. Environmental impact analysis showed that within the study area half of urban roadways and one-third of rural roadways in highly sensitive aquatic areas were amenable to VFS. Construction of VFS in these amenable areas would reduce total loadings to sensitive aquatic areas in urban areas by 26% for TSS, copper, and zinc, and by 10% for phosphorus, and nitrogen and by 21% for lead. The impact for rural sensitive areas was even greater where the VFS had potential to reduce total loadings to sensitive aquatic areas by 38% for TSS, copper, and zinc, by 15% for phosphorus and nitrogen, and by 31% for lead. This research showed an approach combining geographic information system (GIS) mapping and economic analysis to document simultaneous evaluation of cost and environmental benefits when considering use of non-traditional land for bioenergy crop production.
Subject(s)
Copper , Environmental Pollutants , Environment , Phosphorus , Nitrogen , ZincABSTRACT
BACKGROUND: The overall goal of the present study is to investigate the economics of an integrated biorefinery converting hybrid poplar into jet fuel, xylitol, and formic acid. The process employs a combination of integrated biological, thermochemical, and electrochemical conversion pathways to convert the carbohydrates in poplar into jet fuel, xylitol, and formic acid production. The C5-sugars are converted into xylitol via hydrogenation. The C6-sugars are converted into jet fuel via fermentation into ethanol, followed by dehydration, oligomerization, and hydrogenation into jet fuel. CO2 produced during fermentation is converted into formic acid via electrolysis, thus, avoiding emissions and improving the process's overall carbon conversion. RESULTS: Three different biorefinery scales are considered: small, intermediate, and large, assuming feedstock supplies of 150, 250, and 760 dry ktonne of poplar/year, respectively. For the intermediate-scale biorefinery, a minimum jet fuel selling price of $3.13/gallon was obtained at a discount rate of 15%. In a favorable scenario where the xylitol price is 25% higher than its current market value, a jet fuel selling price of $0.64/gallon was obtained. Co-locating the biorefinery with a power plant reduces the jet fuel selling price from $3.13 to $1.03 per gallon. CONCLUSION: A unique integrated biorefinery to produce jet fuel was successfully modeled. Analysis of the biorefinery scales shows that the minimum jet fuel selling price for profitability decreases with increasing biorefinery scale, and for all scales, the biorefinery presents favorable economics, leading to a minimum jet fuel selling price lower than the current price for sustainable aviation fuel (SAF). The amount of xylitol and formic produced in a large-scale facility corresponds to 43% and 25%, respectively, of the global market volume of these products. These volumes will saturate the markets, making them infeasible scenarios. In contrast, the small and intermediate-scale biorefineries have product volumes that would not saturate current markets, does not present a feedstock availability problem, and produce jet fuel at a favorable price given the current SAF policy support. It is shown that the price of co-products greatly influences the minimum selling price of jet fuel, and co-location can further reduce the price of jet fuel.
ABSTRACT
Measurements are reported of the cross-correlation of spectra of differential position signals from the Fermilab Holometer, a pair of colocated 39 m long, high power Michelson interferometers with flat broadband frequency response in the MHz range. The instrument obtains sensitivity to high frequency correlated signals far exceeding any previous measurement in a broad frequency band extending beyond the 3.8 MHz inverse light-crossing time of the apparatus. The dominant but uncorrelated shot noise is averaged down over 2×10^{8} independent spectral measurements with 381 Hz frequency resolution to obtain 2.1×10^{-20}m/sqrt[Hz] sensitivity to stationary signals. For signal bandwidths Δf>11 kHz, the sensitivity to strain h or shear power spectral density of classical or exotic origin surpasses a milestone PSD_{δh}
ABSTRACT
Archival scales from 603 sockeye salmon (Oncorhynchus nerka), sampled from May to July 1924 in the lower Columbia River, were analysed for genetic variability at 12 microsatellite loci and compared to 17 present-day O. nerka populations-exhibiting either anadromous (sockeye salmon) or nonanadromous (kokanee) life histories-from throughout the Columbia River Basin, including areas upstream of impassable dams built subsequent to 1924. Statistical analyses identified four major genetic assemblages of sockeye salmon in the 1924 samples. Two of these putative historical groupings were found to be genetically similar to extant evolutionarily significant units (ESUs) in the Okanogan and Wenatchee Rivers (pairwise F(ST) = 0.004 and 0.002, respectively), and assignment tests were able to allocate 77% of the fish in these two historical groupings to the contemporary Okanogan River and Lake Wenatchee ESUs. A third historical genetic grouping was most closely aligned with contemporary sockeye salmon in Redfish Lake, Idaho, although the association was less robust (pairwise F(ST) = 0.060). However, a fourth genetic grouping did not appear to be related to any contemporary sockeye salmon or kokanee population, assigned poorly to the O. nerka baseline, and had distinctive early return migration timing, suggesting that this group represents a historical ESU originating in headwater lakes in British Columbia that was probably extirpated sometime after 1924. The lack of a contemporary O. nerka population possessing the genetic legacy of this extinct ESU indicates that efforts to reestablish early-migrating sockeye salmon to the headwater lakes region of the Columbia River will be difficult.
Subject(s)
Biological Evolution , Conservation of Natural Resources , DNA/analysis , Genetics, Population/methods , Salmon/genetics , Animals , British Columbia , DNA/genetics , Microsatellite Repeats , Rivers , Salmon/classificationABSTRACT
Sweat testing is a noninvasive technique for monitoring drug exposure over a 7-day period in treatment, criminal justice, and employment settings. We evaluated Delta(9)-tetrahydrocannabinol (THC) excretion in 11 daily cannabis users after cessation of drug use. PharmChek sweat patches worn for 7 days were analyzed for THC by gas chromatography-mass spectrometry (GC/MS). The limit of quantification (LOQ) for the method was 0.4 ng THC/patch. Sweat patches worn the first week of continuously monitored abstinence had THC above the United States Substance Abuse Mental Health Services Administration's proposed cutoff concentration for federal workplace testing of 1 ng THC/patch. Mean+/-S.E.M. THC concentrations were 3.85+/-0.86 ng THC/patch. Eight of 11 subjects had negative patches the second week and one produced THC positive patches for 4 weeks of monitored abstinence. We also tested daily and weekly sweat patches from seven subjects who were administered oral doses of up to 14.8 mg THC/day for five consecutive days. In this oral THC administration study, no daily or weekly patches had THC above the LOQ; concurrent plasma THC concentrations were all less than 6.1 microg/L. In conclusion, using proposed federal cutoff concentrations, most daily cannabis users will have a positive sweat patch in the first week after ceasing drug use and a negative patch after subsequent weeks, although patches may remain positive for 4 weeks or more. Oral ingestion of up to 14.8 mg THC daily does not produce a THC positive sweat patch test.
Subject(s)
Dronabinol/analysis , Marijuana Abuse/diagnosis , Psychotropic Drugs/analysis , Sweat/chemistry , Administration, Oral , Adult , Double-Blind Method , Dronabinol/administration & dosage , Female , Forensic Toxicology , Gas Chromatography-Mass Spectrometry , Humans , Male , Psychotropic Drugs/administration & dosage , Substance Abuse Detection , Time FactorsABSTRACT
Widespread population extirpations and the consequent loss of ecological, genetic, and life-history diversity can lead to extinction of evolutionarily significant units (ESUs) and species. We attempted to systematically enumerate extinct Pacific salmon populations and characterize lost ecological, life history, and genetic diversity types among six species of Pacific salmon (Chinook [Oncorhynchus tshawytscha], sockeye [O. nerka], coho [O. kisutch], chum [O. keta], and pink salmon [O. gorbuscha] and steelhead trout [O. mykiss]) from the western contiguous United States. We estimated that, collectively, 29% of nearly 1400 historical populations of these six species have been lost from the Pacific Northwest and California since Euro-American contact. Across all species there was a highly significant difference in the proportion of population extinctions between coastal (0.14 extinct) and interior (0.55 extinct) regions. Sockeye salmon (which typically rely on lacustrine habitats for rearing) and stream-maturing Chinook salmon (which stay in freshwater for many months prior to spawning) had significantly higher proportional population losses than other species and maturation types. Aggregate losses of major ecological, life-history, and genetic biodiversity components across all species were estimated at 33%, 15%, and 27%, respectively. Collectively, we believe these population extirpations represent a loss of between 16% and 30% of all historical ESUs in the study area. On the other hand, over two-thirds of historical Pacific salmon populations in this area persist, and considerable diversity remains at all scales. Because over one-third of the remaining populations belong to threatened or endangered species listed under the U.S. Endangered Species Act, it is apparent that a critical juncture has been reached in efforts to preserve what remains of Pacific salmon diversity. It is also evident that persistence of existing, and evolution of future, diversity will depend on the ability of Pacific salmon to adapt to anthropogenically altered habitats.
Subject(s)
Biodiversity , Extinction, Biological , Salmon/physiology , Animals , Biological Evolution , Demography , Pacific StatesABSTRACT
Fifty-three head hair specimens were collected from 38 males with a history of cannabis use documented by questionnaire, urinalysis and controlled, double blind administration of delta9-tetrahydrocannabinol (THC) in an institutional review board approved protocol. The subjects completed a questionnaire indicating daily cannabis use (N=18) or non-daily use, i.e. one to five cannabis cigarettes per week (N=20). Drug use was also documented by a positive cannabinoid urinalysis, a hair specimen was collected from each subject and they were admitted to a closed research unit. Additional hair specimens were collected following smoking of two 2.7% THC cigarettes (N=13) or multiple oral doses totaling 116 mg THC (N=2). Cannabinoid concentrations in all hair specimens were determined by ELISA and GCMSMS. Pre- and post-dose detection rates did not differ statistically, therefore, all 53 specimens were considered as one group for further comparisons. Nineteen specimens (36%) had no detectable THC or 11-nor-9-carboxy-THC (THCCOOH) at the GCMSMS limits of quantification (LOQ) of 1.0 and 0.1 pg/mg hair, respectively. Two specimens (3.8%) had measurable THC only, 14 (26%) THCCOOH only, and 18 (34%) both cannabinoids. Detection rates were significantly different (p<0.05, Fishers' exact test) between daily cannabis users (85%) and non-daily users (52%). There was no difference in detection rates between African-American and Caucasian subjects (p>0.3, Fisher's exact test). For specimens with detectable cannabinoids, concentrations ranged from 3.4 to >100 pg THC/mg and 0.10 to 7.3 pg THCCOOH/mg hair. THC and THCCOOH concentrations were positively correlated (r=0.38, p<0.01, Pearson's product moment correlation). Using an immunoassay cutoff concentration of 5 pg THC equiv./mg hair, 83% of specimens that screened positive were confirmed by GCMSMS at a cutoff concentration of 0.1 pg THCCOOH/mg hair.
Subject(s)
Dronabinol/analogs & derivatives , Dronabinol/analysis , Hair/chemistry , Hallucinogens/analysis , Adult , Double-Blind Method , Dronabinol/administration & dosage , Enzyme-Linked Immunosorbent Assay , Forensic Toxicology , Gas Chromatography-Mass Spectrometry , Hallucinogens/administration & dosage , Humans , Male , Marijuana Abuse , Marijuana Smoking , Substance Abuse DetectionABSTRACT
Estimating the time of last cannabis use is important in assessing possible impairment of drivers involved in accidents, in verifying accuracy of court testimony and in the future, helpful in therapeutic monitoring of cannabis agonists. In 1992, Huestis et al developed model 1, based on plasma Delta-tetrahydrocannabinol (THC) concentrations, and model 2, on plasma 11-nor-9-carboxy-Delta(9)-tetrahydrocannbinol/THC ratios, that predicted 95% confidence intervals for time of last cannabis use. These models seemed to be valuable when applied to the small amount of data from published studies of oral ingestion, a route of administration more popular with the advent of cannabis therapies. A study was designed to further validate the models after oral ingestion of THC, and to determine whether they could predict last usage after multiple oral doses. Eighteen subjects in IRB-approved studies participated after providing informed consent. Each of 12 subjects in one group received a single 10 mg oral dose of dronabinol (synthetic THC). In another protocol, 6 subjects received 4 different oral daily doses, divided into thirds and administered with meals for 5 consecutive days. There was a 10-day washout period between each dosing regimen. Daily doses were 0.39, 0.47, and 14.8 mg THC in hemp oil and 7.5 mg dronabinol. Blood specimens were collected throughout the study and analyzed for plasma THC and 11-nor-9-carboxy-Delta(9)-tetrahydrocannbinol by gas chromatography/mass spectrometry with limits of quantification (LOQs) of 0.5 and 1.0 ng/mL, respectively. Actual times between ingestion of THC and blood collection spanned 0.5 to 16 hours. All plasma specimens with analyte concentrations >LOQ (n=90) were evaluated. Models 1 and 2 correctly predicted time of last THC ingestion for 74.4% and 90.0% of plasma specimens, respectively. 96.7% of predicted times were correct with one overestimate and 2 underestimates using the time interval defined by the lowest and highest 95% confidence limit of both models. These results provide further evidence of the usefulness of the predictive models in estimating the time of last oral THC ingestion after single or multiple doses.
Subject(s)
Cannabis/chemistry , Dronabinol/analogs & derivatives , Dronabinol/blood , Substance Abuse Detection/methods , Administration, Oral , Adult , Cannabis/metabolism , Capsules , Dose-Response Relationship, Drug , Double-Blind Method , Dronabinol/administration & dosage , Dronabinol/pharmacokinetics , Drug Administration Schedule , Female , Humans , Male , Middle Aged , Models, Statistical , Psychotropic Drugs/administration & dosage , Psychotropic Drugs/blood , Psychotropic Drugs/pharmacokinetics , Reproducibility of Results , Time FactorsABSTRACT
A clinical study to investigate the pharmacokinetics and pharmacodynamics of oral tetrahydrocannabinol was performed. This randomized, double-blind, placebo-controlled, within-subject, inpatient study compared the effects of THC-containing hemp oils in liquid and capsule form to dronabinol (synthetic THC) in doses used for appetite stimulation. The National Institute on Drug Abuse Institutional Review Board approved the protocol and each participant provided informed consent. Detection times and concentrations of THC, 11-hydroxy-Delta-tetrahydrocannabinol (11-OH-THC), and 11-nor-9-carboxy-Delta-tetrahydrocannabinol (THCCOOH) in plasma were determined by gas chromatography-mass spectrometry [limits of quantification (LOQ)=0.5, 0.5, and 1.0 ng/mL, respectively] after oral THC administration. Six volunteers ingested liquid hemp oil (0.39 and 14.8 mg THC/d), hemp oil in capsules (0.47 mg THC/d), dronabinol capsules (7.5 mg THC/d), and placebo. Plasma specimens were collected during and after each dosing condition. THC and 11-OH-THC concentrations were low and never exceeded 6.1 ng/mL. Analytes were detectable 1.5 hour after initiating dosing with the 7.5 mg THC/d regimen and 4.5 hour after starting the 14.8 mg THC/d sessions. THCCOOH was detected 1.5 hour after the first dose, except for the 0.47 mg THC/d session, which required 4.5 hour for concentrations to reach the LOQ. THCCOOH concentrations peaked at 3.1 ng/mL during dosing with the low-dose hemp oils. Plasma THC and 11-OH-THC concentrations were negative for all participants at all doses within 15.5 hours after the last THC dose. Plasma THCCOOH persisted for at least 39.5 hours after the end of dosing and at much higher concentrations (up to 43.0 ng/mL). This study demonstrated that subjects who used high THC content hemp oil (347 mug/mL) as a dietary supplement had THC and metabolites in plasma in quantities comparable to those of patients using dronabinol for appetite stimulation. There was a significant correlation between body mass index and Cmax and body mass index and number of specimens positive for THC and 11-OH-THC.
Subject(s)
Cannabinoids/blood , Dronabinol/analogs & derivatives , Dronabinol/blood , Administration, Oral , Body Mass Index , Cannabinoids/administration & dosage , Cannabinoids/pharmacokinetics , Capsules , Dose-Response Relationship, Drug , Double-Blind Method , Dronabinol/administration & dosage , Dronabinol/pharmacokinetics , Drug Administration Schedule , Gas Chromatography-Mass Spectrometry , Humans , Metabolic Clearance Rate , Plant Oils/administration & dosage , Plant Oils/chemistry , Psychotropic Drugs/administration & dosage , Psychotropic Drugs/blood , Psychotropic Drugs/pharmacokineticsABSTRACT
Understanding the pharmacokinetics of orally administered cannabinoids is vitally important for optimizing therapeutic usage and to determine the impact of positive tests on drug detection programs. In this study, gas chromatography-mass spectrometry (limit of quantitation = 2.5 ng/mL) was used to monitor the excretion of total 11-nor-9-carboxy-Delta(9)-tetrahydrocannabinol (THCCOOH) in 4381 urine voids collected from seven participants throughout a controlled clinical study of multiple oral doses of THC. The National Institute on Drug Abuse Institutional Review Board approved the study and each participant provided informed consent. Seven participants received 0, 0.39, 0.47, 7.5, and 14.8 mg THC/day for five days in this double blind, placebo-controlled, randomized protocol conducted on a closed research ward. No significant differences (P = 0.05) were observed in mean time of maximum excretion rate, mean maximum excretion rate, and mean terminal elimination half-life (t(1/2)) between the four THC doses, with ranges of 67.4 to 94.9 h, 0.9 to 16.3 micro g/h, and 44.2 to 64.0 h, respectively. Mean apparent elimination t(1/2) of 24.1 +/- 7.8 and 21.1 +/- 4.3 h for the 7.5 and 14.8 mg/day doses, respectively, were calculated from the excretion rate curve prior to the last urine sample with a THCCOOH concentration >/= 15 ng/mL. An average of only 2.9 +/- 1.6%, 2.5 +/- 2.7%, 1.5 +/- 1.4%, and 0.6 +/- 0.5% of the THC in the 0.39, 0.47, 7.5, and 14.8 mg/day doses, respectively, was excreted as THCCOOH in the urine over each 14-day dosing session. This study demonstrated that the terminal urinary elimination t(1/2) of THCCOOH following oral administration was approximately two to three days for doses ranging from 0.39 to 14.8 mg/d. These data also demonstrate that the apparent urinary elimination t(1/2) of THCCOOH prior to reaching a 15 ng/mL concentration is significantly shorter than the terminal urinary elimination t(1/2). These controlled drug administration data should assist in the interpretation of urine cannabinoid results and provide clinicians with valuable information for future pharmacological studies.
Subject(s)
Analgesics, Non-Narcotic/pharmacokinetics , Cannabis , Dronabinol/analogs & derivatives , Dronabinol/pharmacokinetics , Dronabinol/urine , Administration, Oral , Analgesics, Non-Narcotic/administration & dosage , Dosage Forms , Dronabinol/administration & dosage , Gas Chromatography-Mass Spectrometry , Half-Life , HumansABSTRACT
A fully validated, highly sensitive and specific method for the extraction and quantification of Delta(9)-tetrahydrocannabinol (THC), 11-hydroxy-Delta(9)-tetrahydrocannabinol (11-OH-THC) and 11-nor-9-carboxy-Delta(9)-tetrahydrocannabinol (THCCOOH) in plasma is presented. This method incorporates Escherichia coli beta-glucuronidase hydrolysis to cleave glucuronic acid moieties to capture total analyte concentrations, and simultaneous solid phase extraction (SPE) of the three analytes in a single eluant with separation and quantification on a bench-top positive chemical ionization (PCI) gas chromatography-mass spectrometry (GC-MS) in the selected ion monitoring (SIM) mode. Quantitation was achieved by the addition of deuterated analogues for each analyte as internal standards (IS). Limits of quantitation (LOQ) were 0.5, 0.5 and 1.0 for THC, 11-OH-THC and THCCOOH, respectively, with linearity ranging up to 50 ng/ml for THC and 11-OH-THC, and 100 ng/ml for THCCOOH. Absolute recoveries ranged from 67.3 to 83.5% for all three analytes. Intra-assay accuracy and precision ranged from 1.2 to 12.2 and 1.4 to 4.7%, respectively. Inter-assay accuracy and precision ranged from 1.4 to 12.2 and 3.1 to 7.3%, respectively. This method was used to analyze plasma samples collected from individuals participating in a controlled oral THC administration study. Statistically significant (P< or =0.05) increases of 40% for 11-OH-THC and 42% for THCCOOH concentrations were found between hydrolyzed and non-hydrolyzed results. This method will be utilized in ongoing controlled cannabinoid administration studies and may be a useful analytical procedure for the fields of forensic toxicology and cannabinoid pharmacology.
Subject(s)
Dronabinol/analogs & derivatives , Dronabinol/blood , Gas Chromatography-Mass Spectrometry/methods , Humans , Reproducibility of Results , Sensitivity and SpecificityABSTRACT
BACKGROUND: Urinary cannabinoid excretion and immunoassay performance were evaluated by semiquantitative immunoassay and gas chromatography-mass spectrometry (GC/MS) analysis of metabolite concentrations in 4381 urine specimens collected before, during, and after controlled oral administration of tetrahydrocannabinol (THC). METHODS: Seven individuals received 0, 0.39, 0.47, 7.5, and 14.8 mg THC/day in this double-blind, placebo-controlled, randomized, clinical study conducted on a closed research ward. THC doses (hemp oils with various THC concentrations and the therapeutic drug Marinol) were administered three times daily for 5 days. All urine voids were collected over the 10-week study and later tested by Emit II, DRI, and CEDIA immunoassays and by GC/MS. Detection rates, detection times, and sensitivities, specificities, and efficiencies of the immunoassays were determined. RESULTS: At the federally mandated immunoassay cutoff (50 microg/L), mean detection rates were <0.2% during ingestion of the two low doses typical of current hemp oil THC concentrations. The two high doses produced mean detection rates of 23-46% with intermittent positive tests up to 118 h. Maximum metabolite concentrations were 5.4-38.2 microg/L for the low doses and 19.0-436 micro g/L for the high doses. Emit II, DRI, and CEDIA immunoassays had similar performance efficiencies of 92.8%, 95.2%, and 93.9%, respectively, but differed in sensitivity and specificity. CONCLUSIONS: The use of cannabinoid-containing foodstuffs and cannabinoid-based therapeutics, and continued abuse of oral cannabis require scientific data for accurate interpretation of cannabinoid tests and for making reliable administrative drug-testing policy. At the federally mandated cannabinoid cutoffs, it is possible but unlikely for a urine specimen to test positive after ingestion of manufacturer-recommended doses of low-THC hemp oils. Urine tests have a high likelihood of being positive after Marinol therapy. The Emit II and DRI assays had adequate sensitivity and specificity, but the CEDIA assay failed to detect many true-positive specimens.