Skin peptides from anurans of the Litoria rubella Group: sequence determination using electrospray mass spectrometry. Opioid activity of two major peptides

Many species of frogs of the genus Litoria secrete bioactive peptides from their skin glands. These peptides are normally host-defence compounds and may have one, or more of the following activities; smooth muscle contraction, analgesic, antimicrobial, antiviral, lymphocyte proliferator (immunomodulator) and neuronal nitric oxide synthase (nNOS) inactivation. Two frog species of the Litoria rubella Group that have been studied before, namely, Litoria electrica and Litoria rubella, are different from other species of the genus Litoria in that they produce small peptides that show neither membrane, lymphocyte nor nNOS activity. In this study we have used electrospray mass spectrometry together with Edman sequencing to identify eight skin peptides of the third member of this Group, Litoria dentata: surprisingly, none of these peptides show activity in our biological screening program. However, two major peptides (FPWL-NH(2) and FPWP-NH(2)) from L. electrica and L. rubella are opioids at the micromolar concentration.

Simultaneous quantification of nicotine, opioids, cocaine, and metabolites in human fetal postmortem brain by liquid chromatography tandem mass spectrometry

A validated method for simultaneous LCMSMS quantification of nicotine, cocaine, 6-acetylmorphine (6AM), codeine, and metabolites in 100 mg fetal human brain was developed and validated. After homogenization and solid-phase extraction, analytes were resolved on a Hydro-RP analytical column with gradient elution. Empirically determined linearity was from 5-5,000 pg/mg for cocaine and benzoylecgonine (BE), 25-5,000 pg/mg for cotinine, ecgonine methyl ester (EME) and 6AM, 50-5000 pg/mg for trans-3-hydroxycotinine (OH-cotinine) and codeine, and 250-5,000 pg/mg for nicotine. Potential endogenous and exogenous interferences were resolved. Intra- and inter-assay analytical recoveries were > or = 92%, intra- and inter-day and total assay imprecision were < or = 14% RSD and extraction efficiencies were > or = 67.2% with < or = 83% matrix effect. Method applicability was demonstrated with a postmortem fetal brain containing 40 pg/mg cotinine, 65 pg/mg OH-cotinine, 13 pg/mg cocaine, 34 pg/mg EME, and 525 pg/mg BE. This validated method is useful for determination of nicotine, opioid, and cocaine biomarkers in brain.

Fate of beta blockers and psycho-active drugs in conventional wastewater treatment

The removal of beta blockers and psycho-active drugs was investigated in a representative conventional German WWTP by long-term measurement campaigns along different biological treatment processes. The activated sludge treatment with an elevated SRT of 18 d was the only process which led to a significant removal of certain beta blockers and psycho-active drugs. The removal efficiency was below 60% for all compounds except for the natural opium alkaloids codeine and morphine being removed by more than 80%. Primary biological transformation and sorption onto sludge as the main removal mechanisms were examined in lab-scale batch experiments. Sorption onto activated sludge was found to be negligible (<3%). The biological transformation could be described by pseudo-first order kinetics and the transformation constants k(biol) were used to predict the removal of beta blockers and psycho-active drugs in an activated sludge unit with a model. For most compounds the removal efficiencies measured on the full-scale WWTP were within the 95% confidence intervals predicted by the model. The results from full-scale measurements and modeling indicate that biological transformation in the nitrification tank together with parameters such as the sludge retention time and the temperature is crucial regarding the biological transformation of beta blockers and psycho-active drugs in conventional WWTPs.

Eliminating solid phase extraction with large-volume injection LC/MS/MS: analysis of illicit and legal drugs and human urine indicators in U.S. wastewaters

Large-volume (1800 microL) injection (LVI) followed by liquid chromatography/tandem mass spectrometry was developed and optimized to eliminate the need for off- and on-line solid phase extraction as a sample preparation step. Centrifugation of raw municipal influent followed by LVI was optimized for the routine determination of illicit drugs and related substances in municipal wastewaters. The accuracy of the method is demonstrated by standard addition for analytes with concentrations ranging from 4 to 3,500,000 ng/L. Precision, as indicated by relative standard deviation is <12% within a day and < or =20% for between-days for analytes with corresponding stable-isotope-labeled internal standards. Instrumental detection limits range from 0.5 to 4 ng/L while lower limits of quantification range from 2.5 to 10 ng/L The method is demonstrated on wastewater treatment plant influents (24 h, flow-normalized) collected from seven municipalities located in the US. Methamphetamine concentrations and loads are the greatest yet reported while cocaine concentrations and index loads are similar to European locations. Creatinine is introduced as human urine indicatorthat can be potentially used as an alternative to population estimates for indexing illicit drug loads for different municipalities.

Study of the newborn feeding behaviors and fentanyl concentration in colostrum after an analgesic dose of epidural and intravenous fentanyl in cesarean section

OBJECTIVE

To compare the effects of epidural and intravenous fentanyl on breast feeding behaviors and fentanyl concentration in the colostrum after an analgesic dose.

METHODS

This study was conducted at the Obstetrics Department of Kasr El-Aini Hospital-Cairo University, Cairo, Egypt. The studied mothers were 100 multipara, who have been subjected to cesarean section, and have a previous history of successful breast feeding. The study was conducted from May 2005 to May 2007. They were divided into 2 groups: group I included 50 patients who received epidural anesthesia with fentanyl, and group II included 50 patients who received spinal anesthesia with intravenous fentanyl, and both groups were observed for initial breast feeding behaviors of newborns, and fentanyl concentration in the colostrum at 45 minutes, and 24 hours after birth.

RESULTS

The study included 100 multipara, 2 samples of colostrum were taken from each patients at 45 minutes, and at 24 hours. The levels of fentanyl concentration were greatest at 45 minutes of the initial sampling time, reaching 0.40+/-0.059 ng/ml in the epidural group, and 0.19+/-0.019 ng/ml in intravenous fentanyl group. There was no statistical difference in breast feeding behaviors at birth, or at 24 hours of age in both groups.

CONCLUSION

Although the levels of fentanyl concentration were greatest at 45 minutes of the initial sampling time, it can be used safely as intravenous or epidural without affecting the initial breast feeding behaviors of the newborn.

[Anaesthetics and breast feeding]

Many women undergo anaesthetic procedures related to childbirth or during the period of lactation. Most anaesthetic drugs are lipophilic and are thus excreted into breast milk. This article summarises available knowledge regarding anaesthetics, their excretion into breast milk and possible effects on the suckling infant. The consequences of such an exposure are discussed in terms of whether breast-feeding should be allowed or not after anaesthetic procedures.

[Chemical-toxicological analysis of butorphanol]

The conditions of butorphanol isolation from biological fluids were studied. The method of its extraction with the mix of organic solvents by pH 12 was proposed. How to identify butorphanol with the methods of thin-layer chromatography, ultraviolet spectrometry, high-performance liquid chromatography, gas chromatography with a detector of electron capture, chromato-mass spectrometry was developed. Possibility of use ultraviolet spectrometry for quantitative assessment of butorphanol was shown.

Pentazocine transport by square-wave AC iontophoresis with an adjusted duty cycle

So far, pentazocine iontophoresis has never been studied, although pentazocine is widely used in pain management. The purpose of this study was to determine whether pentazocine transportation through a cellophane membrane could be enhanced using square-wave alternating current (AC) iontophoresis with an adjusted duty cycle and dependence on the voltage and the duty cycle. Voltages of 10, 25 and 40 V with duty cycles of 50%, 51%, 52%, 53%, 54% and 55% were applied for 60 minutes at a high frequency of 1 MHz to diffusion cells on both sides of a cellophane membrane. The donor compartment was filled with a solution containing pentazocine. Square-wave AC iontophoresis with an adjusted duty cycle enhanced pentazocine transportation at higher voltages and duty cycles. These results suggested that the direct current (DC) component of the square-wave AC played an important role in enhancing pentazocine transportation despite changes in polarity at very high frequency of 1 MHz. The higher voltages and duty cycles induced a pH change. The practical electrical conditions that could be applied clinically were 25 V with a 54% duty cycle or 40 V with a 53% duty cycle.

Simultaneous quantitative determination of amphetamines, ketamine, opiates and metabolites in human hair by gas chromatography/mass spectrometry

A gas chromatography/mass spectrometry (GC/MS) method was developed and validated for the determination of common drugs of abuse in Asia. The method was able to simultaneously quantify amphetamines (amphetamine; AP, methamphetamine; MA, methylenedioxy amphetamine; MDA, methylenedioxymeth mphetamine; MDMA, methylenedioxy ethylamphetamine; MDEA), ketamine (ketamine; K, norketamine; NK), and opiates (morphine; MOR, codeine; COD, 6-acetylmorphine; 6-AM) in human hair. Hair samples (25 mg) were washed, cut, and incubated overnight at 25 degrees C in methanol/trifluoroacetic acid (methanol/TFA). The samples were extracted by solid-phase extraction (SPE), derivatized using heptafluorobutyric acid anhydride (HFBA) at 70 degrees C for 30 min, and the derivatives were analyzed by electron ionization (EI) GC/MS in selected ion monitoring mode. Confirmation was accomplished by comparing retention times and the relative abundances of selected ions with those of standards. Deuterated analogs of the analytes were used as internal standards for quantification. Calibration curves for ten analytes were established in the concentration range 0.1-10 ng/mg with high correlation coefficients (r2 > 0.999). The intra-day and inter-day precisions were within 12.1% and 15.8%, respectively. The intra-day and inter-day accuracies were between -8.7% and 10.7%, and between -5.9% and 13.8%, respectively. The limit of detection (LOD) and limit of quantification (LOQ) obtained were 0.03 and 0.05 ng/mg for AP, MA, MDA, MDMA and MDEA; 0.05 and 0.08 ng/mg for K, NK, MOR and COD; and 0.08 and 0.1 ng/mg for 6-AM. The recoveries were above 88.6% for all the compounds, except K and NK which were in the range of 71.7-72.7%. Eight hair samples from known polydrug abusers were examined by this method. These results show that the method is suitable for broad-spectrum drug testing in a single hair specimen.

Cause of death and drug use pattern in deceased drug addicts in Sweden, 2002–2003

Compared with their contemporaries, individuals abusing illicit drugs suffer a higher risk of premature death. In Sweden, a simple protocol for registration of fatalities among abusers of alcohol, pharmaceuticals, illicit drugs, or other substances, has been used by the forensic pathologists since 2001. This routine was introduced to allow for an evaluation of the cause and manner of death, and patterns of abuse among different groups of abusers. We explored the data on drug abusers (i.e. abusers of illicit drugs) subjected to a forensic autopsy 2002-2003. The Swedish forensic pathologists examined 10,273 dead victims during the study period and 7% (743/10,273) of the cases were classified as drug abusers. Toxicological analyses were carried out in 99% (736/743) and illicit drugs were detected in 70% (514/736) of these. On average, 3.8 substances (legal or illegal) were found per case. The most common substances were ethanol and morphine, detected in 43 and 35% of the cases, respectively. When exploring the importance of the different substances for the cause of death, we found that the detection of some substances, such as fentanyl and morphine, strongly indicated a poisoning, whereas certain other substances, such as benzodiazepines more often were incidental findings. In total, 50% (372/743) died of poisoning, whereas only 22% (161/743) died of natural causes. Death was considered to be directly or indirectly due to drug abuse in 47% (346/743), whereas evidence of drug abuse was an incidental finding in 21% (153/743) or based on case history alone in 33% (244/743). We believe that this strategy to prospectively categorize deaths among drug addicts constitutes a simple means of standardizing the surveillance of the death toll among drug addicts that could allow for comparisons over time and between countries.

Fatal Candida tropicalis infection in an 8-month-old infant with an aplasia of the thymus as a rare cause of death in infancy

Anomalies of the thymus can lead to immunodeficiencies that are often associated with complex syndromes. The clinical relevance of those anomalies varies a lot. Regarding mortality and morbidity, opportunistic infections play a major role in immunocompromised individuals.

CASE REPORT

An 8-month-old infant died of a sepsis with multi-organ failure after 32 days in intensive care. At autopsy, no thymus gland could be found; toxicological examinations yielded high morphine concentrations. Autopsy findings and the results of further examinations performed postmortem are discussed in view of the clinical findings, the classification and the cause of death.

Concentrations of methadone in breast milk and plasma in the immediate perinatal period

This study evaluates concentrations of methadone in breast milk and plasma among a sample of methadone-maintained women in the immediate perinatal period. Twelve methadone-maintained, lactating women provided blood and breast milk specimens 1, 2, 3, and 4 days after delivery. Specimens were collected at the time of trough (just before methadone dose) and peak (3 hours after dosing) maternal methadone levels. Paired specimens of foremilk (prefeed) and hindmilk (postfeed) were obtained at each sampling time. Although there was a significant increase in methadone concentration in breast milk over time for the peak postfeed sampling time, t (22)=2.40, P=.0255, methadone concentrations in breast milk were small, ranging from 21 to 314 ng/mL, and were unrelated to maternal methadone dose. Results obtained from this study contribute to the recommendation of breastfeeding for methadone-maintained women regardless of methadone dose.

Oral fluid as an alternative matrix to monitor opiate and cocaine use in substance-abuse treatment patients

Interest in oral fluid as an alternative matrix for monitoring drug use is due to its ease-of-collection and non-invasiveness; however, limited data are available on the disposition of drugs into oral fluid. The objective of this research was to provide data on the presence and concentrations of heroin, cocaine and multiple metabolites in oral fluid after illicit opioid and cocaine use. Thrice weekly oral fluid specimens (N=403) from 16 pregnant opiate-dependent women were obtained with the Salivette oral fluid collection device. Evidence of heroin (N=62) and cocaine (N=130) use was detected in oral fluid by LC-APCI-MS/MS. 6-Acetylmorphine (6-AM), heroin and morphine were the major opiates detected, with median concentrations of 5.2, 2.3, and 7.5 microg/L, respectively. Cocaine and benzoylecgonine (BE) had median concentrations of 6.4 and 3.4 microg/L. Application of the Substance Abuse Mental Health Services Administration (SAMHSA) recommended cutoffs for morphine and codeine (40 microg/L), 6-AM (4 microg/L) and cocaine and BE (8 microg/L), yielded 28 opiate- and 50 cocaine-positive specimens. Oral fluid is a promising alternative matrix to monitor opiate and cocaine use in drug testing programs. These data guide interpretation of oral fluid test results and evaluate currently proposed SAMHSA oral fluid testing cutoffs.

Validated GC–MS analysis for the determination of residual fentanyl in applied Durogesic® reservoir and Durogesic® D-Trans® matrix transdermal fentanyl patches

The method development and validation characteristics are described of a simple gas chromatographic-mass spectrometric (GC-MS) analytical procedure to determine residual fentanyl in used Durogesic reservoir patches and Durogesic D-Trans matrix technology based systems to estimate the actual rate of transdermal fentanyl delivered in individual patients. The sample preparation protocol constituting a saline based extraction of sets of new patches of each nominal dose available, resulted in fentanyl extraction recoveries to increase steadily as a function of increasing extraction time. For the reservoir type transdermal therapeutic system (TTS), fentanyl extraction efficiencies at equilibrium (16 h) ranged from approximately 60% (100-microg/h TTS) to 95% (25-microg/h TTS), whereas for the matrix type system considerable lower recoveries were demonstrated for the highest nominal dose rates (35%-52%), while reaching 90% for the 25-microg/h system. For the latter type of fentanyl TTS, an optimized methanol based extraction protocol yielded virtually quantitative fentanyl recoveries for each matrix patch nominal dose level at substantially shorter extraction periods (15 min). The GC-MS analytical method using selected ion monitoring (SIM) and deuterated fentanyl as internal standard was shown to be adequately selective with regard to the presence of other compounds in the Durogesic patches. It was further demonstrated that the developed analytical protocols provided highly reproducible and accurate estimates of the initial fentanyl content of each patch type at all available nominal doses, with coefficients of variation and relative errors generally below 10%. These advantageous assay validation characteristics can be further transposed to the application of residual fentanyl level estimates in used patches, provided that with each batch of samples also a set of new TTSs with equal dose is assayed to perfectly mimic extraction phenomena. Finally, the presented GC-MS analytical protocol was successfully applied for the determination of residual fentanyl in a subset of 57 reservoir type patches obtained from four palliative patients.

Morphine and its metabolites: Analytical methodologies for its determination

The present article reviews the methods of determination published for morphine and its metabolites covering the period from 1980 until at the first part of 2006. The overview includes the most relevant analytical determinations classified in the following two types: (1) non-chromatographic methods and (2) chromatographic methods.

Determination of opiate alkaloids in process liquors using capillary electrophoresis

This paper describes the determination of opiate alkaloids (morphine, codeine, oripavine and thebaine) in industrial process liquors using capillary zone electrophoresis with UV-absorption detection at 214 nm. A study of cyclodextrin type and concentration revealed that the addition of 30 mM hydroxypropyl-beta-cyclodextrin to the electrolyte solution (100mM Tris adjusted to pH 2.8) was suitable to resolve the four analytes of interest. Typical analysis time was 12 min and the limit of detection for each alkaloid was 2.5 x 10(-6) M. The results for the proposed methodology were in good agreement with those of a conventional HPLC procedure. Under the same conditions, short-end injection was used to reduce the effective separation length from 41.5 to 8.5 cm, which allowed the determination of morphine and thebaine in process liquors within 2.5 min.

[Determination of tramadol hydrochloride in serum samples by disk solid phase extraction and gas chromatography-mass spectrometry in selected ion monitoring]

OBJECTIVE

Disk solid phase extraction (SPE) was assessed for tramadol hydrochloride from serum.

METHODS

The SPE was performed with SPEC C18AR/MP3 Disk SPE cartridge, offering hydrophobic C18 and strong cation ionic exchange interactions for the analytes, before being added into extraction column, 1 mL serum was diluted by 2 mL 0.1 mol/L phosphate buffer solution (pH 6) and the eluent was ethyl acetate containing 2% ammonia. Then SKF525 was added as internal standard into samples, which would be extracted simultaneously with analyte,quantitatively, determined by GC/MS/SIM.

RESULTS

The extraction recovery of tramadol hydrochloride was 98.9%, 92.5% and 84.8% for serum samples with corresponding amounts of standard addition of 0.1 microg/mL, 0.2 microg/mL and 0.5 microg/mL. And RSD measured 5 times was 3.2%, 8.7% and 10.9% respectively. The linear range varied from 0.1 microg/mL to 4 microg/mL. The multinomial regression correlation coefficient (r2) equaled 0.9939, and the detection limit was 21 ng/mL. After the same extraction column was continuously used for 5 times, there was no jam, pollution and decline of recovery and RSD.

CONCLUSION

This method is suitable for forensic toxicological analysis.

[Hair analysis of abused and therapeutic drugs in forensic toxicology]

Hair analysis for abused drugs has been gaining increasing significance in forensic sciences. Hair is a special matrix for the retrospective investigation of chronic drug abuse or poisoning in criminal cases and allows to demonstrate with sensitive methods even a single administration in low amount. Segmental hair analysis can yield the information about the time course of the substance use. The background of drug incorporation mechanism is not yet understood in full details and cannot be evaluated exactly in all cases. The hair sampling, sample preparation, analytical performance are very important for final results. The outcomes of hair analysis have been reviewed by dividing into six groups: opiates, cocaine, amphetamines, cannabinoids, abused therapeutic drugs and the markers of chronic alcohol consumption.

[Hollow fiber liquid phase microextraction of tramadol from water and biological samples]

A novel technique of liquid phase microextraction supported by hollow fiber membrane (LPME-HFM) was applied to extract tramadol in tap water, urine and human plasma. At room temperature (20 degrees C), polyvinylidene fluoride hollow fiber membrane (PVDF-HFM) was employed. In the procedure of extraction, 4 microL of organic solvent (toluene) was used in individual extraction. Pethidine was used as the internal standard (IS) in the sample analysis by gas chromatography with flame ionization detector (GC-FID). The optimized conditions for tramadol extraction was as follows: toluene as organic solvent, 4 mL sample solution added with 0.1 mL of 1 mol/L NaOH solution, extraction time of 15 mm, and stirring speed of 300 r/min. The sample solutions, containing a series of concentrations of tramadol, 0.05, 0.10, 0.50, 1.0, 5.0, 10.0 mg/L, were analyzed. The good linearities were obtained for water, human urine and human plasma samples with the correlation coefficients of 0.999 7, 0.994 8 and 0.998 5, respectively. The detection limits can reach 0.01 mg/L for water and human urine and 0.05 mg/L for human plasma. The relative standard deviations (RSDs) were 10.6% and 5.15% for water, 18. 1% and 4. 03% for urine solution at the spiked levels of 0.1 and 1.0 mg/L. The RSDs were 16.6% and 4.15% for plasma solution at the spiked levels of 0.5 and 1.0 mg/L. In comparison with conventional method, this method is simple, sensitive, fast, inexpensive, and environmentally friendly. It can be applied to pharmaceutical and forensic analysis.

LC-MS/MS analysis of fentanyl and norfentanyl in a fatality due to application of multiple Durogesic transdermal therapeutic systems

Fentanyl is a potent synthetic narcotic analgesic administered in the form of a transdermal patch for the management of chronic pain. A 78-year-old woman with a history of cancer was found dead in bed. She was lying on her back. The external examination revealed 10 Durogesic transdermal therapeutic systems (100 microg/h fentanyl) on the body. Liquid-liquid extraction and liquid chromatography tandem mass spectrometry with electrospray source in positive ionization mode was applied for the quantitation of fentanyl and its major metabolite norfentanyl in the post-mortem samples. Fentanyl-d5 and norfentanyl-d5 were used as internal standards. Multiple reaction monitoring was used for specific detection. Calibration was performed by addition of standard solutions to drug-free matrix (blood, urine and liver) prior to extraction. The method showed good linearity for fentanyl and norfentanyl over a concentration range of 5-150 microg/L in reconstituted extracts with coefficients of determination equal or greater than 0.998. Percent mean within-day precision and accuracy of 0.9-1.0% and 99.4-101.1% for fentanyl and 2.0-4.5% and 93.1-101.0% for norfentanyl were obtained. Mean extraction recoveries varied between 95.5% and 100.3% for fentanyl and 39.2-57.4% for norfentanyl. The following fentanyl (norfentanyl) concentration in the post-mortem samples were measured; 28.6 microg/L (3.0 microg/L) in right and 28.2 microg/L (3.5 microg/L) in left subclavian blood, 21.3 microg/L (<2 microg/L) in right and 20.9 microg/L (<2 microg/L) in left femoral blood, 37.6 microg/L (4.2 microg/L) in right and 33.9 microg/L (4.4 microg/L) in left ventricular blood, 282.9 microg/L (121.2 microg/L) in urine, 688.2 microg/L in stomach contents, 122.5 microg/L (25.4 microg/L) in bile, 19.5 microg/L (< 2 microg/L) in vitreous humour, 203.0 microg/kg (26.6 microg/kg) in liver and 78.6 microg/kg (46.3 microg/kg) in kidney. We concluded that the woman's death was caused by acute intoxication with fentanyl. The manner of death was presumed to be suicide due to excessive administered Durogesic transdermal therapeutic systems.

An automated and fully validated LC-MS/MS procedure for the simultaneous determination of 11 opioids used in palliative care, with 5 of their metabolites

A fully validated liquid chromatographic procedure coupled with electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) is presented for quantitative determination of the opioids buprenorphine, codeine, fentanyl, hydromorphone, methadone, morphine, oxycodone, oxymorphone, piritramide, tilidine, and tramadol together with their metabolites bisnortilidine, morphine-glucuronides, norfentanyl, and nortilidine in blood plasma after an automatically performed solid-phase extraction (SPE). Separation was achieved in 35 min on a Phenomenex C12 MAX-RP column (4 microm, 150 x 2 mm) using a gradient of ammonium formiate buffer (pH 3.5) and acetonitrile. The validation data were within the required limits. The assay was successfully applied to authentic plasma samples, allowing confirmation of the diagnosis of overdose situations as well as monitoring of patients' compliance, especially in patients under palliative care.

[Study on colloidal gold labeled anti-buprenorphine monoclonal antibody for rapid test kit to detect buprenorphine]

OBJECTIVE

To develope an easy to use, rapid and accurate test for detecting buprenorphine based on the principle of competitive immunoassay.

METHODS

Monoclonal antibody against buprenorphine was conjugated with colloidal gold and dispensed on the glass fiber. The complete antigen Buprenorphine-BSA and the goat anti-mouse IgG polyclonal antibody were separately sprayed on the nitrocellulose membrane as the test line (T line) and the control line (C line). The rapid test kit was the final assembled product of test strip with the plastic cover.

RESULTS

A total of 100 urine samples were tested for buprenorphine by immunochromatographic and GC/ MS methods. The accuracy was 99.0%. It is found the test kit can only detect by cross reaction with other 45 kind drugs.

CONCLUSION

Rapid test kit can detect buprenorphine in the samples in 5 minutes. The cut-off value of the test is 100 ng/mL.