The competitive binding takes place between the antibody, the THC in the sample, and a constant concentration of tracer added to the sample. This tracer consists of THC conjugated with an enzyme peroxidase or alkaline phosphatase attached to the plate, which is detected by a specific substrate. The reaction of substrate will be at maximum if THC is not present in the sample because only the tracer enzyme will stick to the antibody coating. On the other hand, the reaction will be very low if the THC concentration in the sample is very high because this will compete with the THC tracer and will prevent the enzyme from being blocked on the plate Grassi et al.
The method was validated according to protocols, which included assessment of accuracy, precision, robustness, stability in meconium and in-process stability, interference and sensitivity and specificity.
The method uses deuterated internal standards for both analytes. This confirmatory method was successfully applied to meconium samples that had screened positive by enzyme-linked immunosorbent assay, and Introduction Several methods have been described for monitoring prenatal exposure to marijuana through analysis of deltatetrahydrocannabinol THC and its metabolites in blood, urine, hair, placenta, amniotic fluid, gastric aspirate 1in umbilical cord tissue 23and meconium 1 — 7.
Meconium, the black tarry substance that begins to collect in the intestine around the 12—16th week of gestation, has emerged as the preferred matrix for monitoring gestational marijuana use by the mother 1.
Meconium can be effectively collected for about 5 days after birth to determine prenatal exposure of the newborn to drugs 14.
It is a complex matrix consisting of water, epithelial cells, lanugo, mucus, amniotic fluid, bile acids, salts, cholesterol, sugars, lipids, various organ secretions, and compounds ingested by the mother during the last few months of the pregnancy 4.
The relative merits of meconium and umbilical cord tissue for the determination of fetal exposure to drugs including cannabis has been assessed 2and it was shown that there was There are advantages and disadvantages for both matrices that need to be taken into consideration.
To test An introduction to the analysis of tetrahydrocannabinol thc umbilical cord it needs to be collected at birth, so prior suspicion of the drug use must be indicated in order to secure the sample, whereas meconium can be collected several days after the birth, so if a need for testing is identified after the birth, samples can still be procured 2.
However, since the umbilical cord sample is collected at birth it can be tested immediately and results are available more quickly than in meconium, since it may take some days to collect a sufficient sample size.
Additionally, the chemical properties of the drug may affect the concentrations of the analytes present in the meconium and cord samples causing different results between the two 2.
Methods for the analysis of umbilical cord tissue can be costly and typically use more advanced instrumentation such as liquid chromatography—time of flight mass spectrometry LC-TOF-MSwhich may not be available in all laboratories 3.
The value of monitoring for marijuana use during pregnancy is debated due to contradictory research on the effects of in utero exposure to the drug. Studies agree that marijuana is one of the most commonly used drugs during pregnancy and is the most common illicit drug used 8.
It has been shown that THC can rapidly cross the placenta, but the exact effects on the fetus are undetermined 8 — Fetal excretion of THC is delayed leading to a more prolonged exposure profile 8.
It has been difficult to reach firm conclusions about the effects of marijuana use during pregnancy due to the number of potentially confounding factors involved, including polysubstance abuse, and socioeconomic factors such as income, social and family support, nutrition, and maternal health including prenatal care, stress, sexually transmitted diseases STDand domestic violence 89.
Some studies agree that there is little to no effect on the gestational length or presence of malformations in the newborn associated with the mother's use of marijuana during the pregnancy 89 One study suggests that there is, however, a possible detrimental effect on growth and length of gestation due to marijuana use during pregnancy, however that report relied only on maternal self-report of drug use which was not confirmed through toxicological testing There are publications that suggest some effect on intelligence and cognitive functioning in neonates resulting from in utero marijuana exposure, but these results have again been inconsistent and may be a function of both genetics and the external environment 89 The exact effects of the drug on the brain and their persistence are not fully understood, but there is believed to be a negative effect on development of systems for mood, cognition and reward and goal driven behaviors No major teratogenic effects or psychotic symptoms have been reported in the newborn associated with prenatal exposure to marijuana 89.
A related consideration is the effect of the marijuana usage on maternal health. If the mother's health is negatively impacted, this might lead to corresponding negative impacts on the fetus's health which may be the actual cause of some inconstancies between studies 9.
Other studies suggest a possible link between prenatal exposure and early onset of marijuana use in the child 89. In addressing some of these conflicting concerns regarding maternal drug use and its effects in utero or in the neonate, there is a need for a reliable and sensitive objective method for demonstrating gestational marijuana use through analysis of meconium.
Because of the complex nature of the meconium matrix, extraction methods often require multiple steps, the use of costly specialized extraction columns 1314high resolution multi-dimensional chromatographic techniques 1415 and long analytical run times 7 to maximize sensitivity and avoid interference.
We describe the development and validation of a robust, cost-effective extraction and instrumental analysis method with a Acetonitrile, methanol, concentrated ammonium hydroxide, concentrated hydrochloric acid, and methylene chloride were obtained from Fisher Scientific, and isopropyl alcohol was obtained from OmniSolv Charlotte, NC.
The column was a ZB50 Phenomenex, part no. Methods Sample preparation, hydrolysis and precipitation Approximately 0. Phosphate buffer pH 7, 0. Acetonitrile 1 mL is added to each tube and mixed well, then centrifuged for 5 min at rpm.
Samples are mixed and then centrifuged at rpm for 5 min.Introduction. Marijuana is a widely used illicit drug generally administered orally or by smoking, resulting in euphoria and hallucinations. In ingesting marijuana, tetrahydrocannabinol (THC) is deposited into the oral cavity, and this may be the primary source of THC collected and measured in oral fluid analysis, rather than the .
Tetrahydrocannabinol Tetrahydrocannabinol (THC) is commonly known and popularized by its significant presence in the cannabis plant, a.k.a., marijuana.
Raphael Mechoulam and Yechiel Gaoni, two Israeli scientists working at the Weizmann Institute of Science, first isolated the organic drug in Grassi, G. Rapid screening tests for the detection of Δ 9-tetrahydrocannabinol (THC) in fibre hemp.
Journal of the International Hemp Association 6(2): A preliminary study was done to assess whether existing tests could be used for detection of Δ 9-tetrahydrocannabinol (THC) in fibre hemp. A very simple test, derived from a .
Deltatetrahydrocannabinol (THC) is a phytocannabinoid, and typically the most abundant cannabinoid present in cannabis products on the market today.
THC can be derived from THCA by non-enzymatic decarboxylation during storage and consumption. This paper describes an efficient and robust method for the analysis of methylamphetamine, MDMA and THC in oral fluid and blood samples by supported liquid extraction and LC/MS analysis.
The method is amenable to full automation and allows for the extraction and . Introduction The US Environmental Protection Agency writes in its immunoassay guidelines that: "Immunoassay can provide real-time field analysis of a wide variety of environmental parameters at a fraction of the cost and time for conventional full protocol laboratory analyses".