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In zootoxinology, drugs such as anesthetics and secretion enhancers are used to increase venom yields, but it is unclear whether this affects the venom composition. After injection of ketamine and pilocarpine into two non-front-fanged snakes, mass spectrometry confirmed the presence of both drugs and their metabolites in the venoms. The quantified high concentrations raise concerns about potential interference in bioassays and pharmacological studies, highlighting the need to consider extraction additives in venom research to ensure unbiased results.

Ketamine is a dissociative anesthetic drug that is abused by teenagers and young adults, commonly for recreational purposes in dance clubs, to generate euphoria and dissociation, and sometimes employed as a date-rape drug. Herein, a highly sensitive, and environmentally friendly spectrofluorimetric method was developed for detection of ketamine in pharmaceutical and plasma samples. The technique is based on a nucleophilic substitution reaction occurring between ketamine and NBD-Cl (4-chloro-7-nitrobenzo-2-oxa-1,3-diazole), resulting in the formation of a fluorescent derivative that exhibits detectability at a remarkable level. The resultant derivative demonstrates its maximum emission intensity at 543 nm upon excitation at a wavelength of 481 nm. Upon optimizing the reaction parameters, a linear relationship was established between the fluorescence intensity of the formed derivative and the concentrations of ketamine within the specified range of 10 - 250 ng/mL. The method demonstrated exceptional sensitivity with detection and quantitation limits of 2.37 ng/mL and 7.18 ng/mL, respectively, allowing for the detection of ketamine in both pharmaceutical and plasma samples. The method was precise (%RSD < 1) accurate (%R = 99.74%) and robust (% R ± SD from 98.00 ± 1.11 to 99.97 ± 0.75). Furthermore, the developed method was compared to the reported method, with the results indicating that the suggested method is more sensitive and ecologically benign.

Fluorinated analogs of ketamine, such as 2-fluoro-deschloroketamine and its isomers, have recently emerged as dissociative anesthetics that act through multiple central nervous system pathways. As their prevalence continues to increase, metabolic studies are critical to confirm their use in suspected cases of abuse. 2-Fluoro-N-propylnordeschloroketamine (2-fluoro-2-oxo-PCPr), in which a propyl group replaces the methyl group of 2-fluoro-deschloroketamine, was seized by investigative authorities in 2025. In this study, we determined the chemical structure of 2-fluoro-2-oxo-PCPr using nuclear magnetic resonance (NMR), gas chromatography-mass spectrometry (GC–MS), and liquid chromatography-quadrupole time-of-flight mass spectrometry (LC–QTOF–MS). Notably, the duplicated NMR signals in the N-propyl region indicated the presence of two interconverting rotameric forms in an approximately 2:1 equilibrium. The structures of the individual rotamers were confirmed by gauge-including atomic orbital (GIAO)-based density functional theory (DFT) NMR calculations. Metabolite profiling was conducted on suspected abusers’ urine using LC–QTOF–MS in conjunction with MetabolitePilot™ software. The identified metabolic pathways included glucuronidation, desaturation, hydrogenation of the cyclohexanone ring, hydroxylation, carboxylation, and N-depropylation. Urine and hair collected from the abusers were analyzed using LC–MS/MS with multiple reaction monitoring transitions to enhance the detection limits. The primary metabolite, nor-2-fluoro-2-oxo-PCPr was detected in both urine and hair, supporting its potential utility as a long-term biomarker. This is the first study to identify the structure of 2-fluoro-2-oxo-PCPr and its metabolites in urine and hair. With the increasing new psychoactive substances abuse and diagnostic challenges, these findings provide key data for detecting and monitoring emerging psychoactive substance in forensic and clinical toxicology. •Structure of new 2-fluoro-2-oxo-PCPr was elucidated using NMR, GC-MS, and LC-QTOF-MS.•Duplicated NMR signals indicated the presence of two interconverting rotameric forms.•Metabolite profiling revealed glucuronidation, hydroxylation, and N-depropylation.•Nor-2-fluoro-2-oxo-PCPr was detected in urine and hair as a key biomarker.•This study provides forensic data for monitoring emerging fluorinated ketamine analogs.

Excessive hormone release, the possibility of sleep disturbances, and a brief and quick improvement in the functioning of many organs, the physiological system, the nerves, etc. are all consequences of the abuse of incentive medications. Illegal narcotics have terrible long-term impacts on human health, including the possibility of death, in addition to their immediate effects. These consequences highlight the need for more obviousness and accuracy in the detection of illicit drugs, as well as for their detection to be done gently, effectively, and consistently. This work introduces an illicit drug sensor based on PCF, with an eye toward these as the primary targets. Three illegal drugs – ketamine, amphetamine, and cocaine – have been simulated for the sensor. Two types of circular air holes in cladding of varying sizes have been developed for a single core PCF. The cladding has three-layer chain and wind turbine-shaped air holes, and a circular air hole in the core region that will be used to field test drug samples, all included to achieve low confinement losses and high sensitivity. A maximum Relative Sensitivity (RS) of 99.92%, 99.12% and 98.83% at ketamine, amphetamine, and cocaine respectively is revealed by the recently established PCF analysis, which was presented out right away. Furthermore, we looked at the Confinement Loss (CL) associated with these illicit drugs, which was around 1.275 × 10 −7 dB/m, 2.653 × 10 −9 dB/m, and 4.106 × 10 −10 dB/m, besides Effective Material Loss (EML) of 0.0042 cm -1 , 0.0044 cm -1 and 0.0045 cm -1 . Refractive index changes in PCF are usually the cause of action for PCF-based biosensors. These modifications have an impact on how light travels within the fiber. Drug molecules interact with light as a result of changes in the optical properties of the core that occur during light propagation through it.

With the decline of the use of ketamine, one of the common drugs of abuse in Hong Kong, detection of ketamine-related analogues in local laboratories has been encountered. Aim: A brief account of the occurrence of fluorodeschloroketamine (FDCK) in forensic cases is reported through a retrospective study of all drug seizures and driving under the influence of drugs (DUID) cases since its first appearance. Methods: Identification of FDCK in drug seizures was achieved through gas chromatography – mass spectrometry (GC-MS) and/or liquid chromatography – diode array detection (LC-DAD) methods while its quantification was performed using gas chromatography – flame ionization detection (GC-FID). For the analysis of blood samples in DUID cases, identification and quantification were performed using LC-MS/MS by monitoring the respective transitions of FDCK and fluorodeschloronorketamine (FDCNK) using ketamine-d4 and norketamine-d4 respectively as internal standards. Results: Since its first submission in November 2018, a total of 74 drug seizure cases (151 items) and 6 drug driving cases were encountered till December 2019. Drug seizures found with FDCK were physically similar to those of ketamine seizures. The majority of items were detected with FDCK only (103 items, ∼67%) or as a mixture of FDCK with ketamine (42 items, ∼28%). The drug purity detected with either FDCK only or FDCK mixed with ketamine was high which was similar to those purity found in ketamine seizures. The blood drug concentrations of FDCK of the 6 drug driving cases were in the range of <0.002–1.1 μg/mL and other psychoactive drug(s)/metabolite(s) were also identified. Except for one case where the analysis of the metabolite, fluorodeschloronorketamine (FDCNK), was not conducted due to insufficient sample, the FDCK (FDCNK) concentrations in blood found in the 6 cases were <0.002 (0.005), 0.002 (0.002), 0.002 (0.003), 0.02 (0.035), 0.87 (0.44) and 1.1 (not determined) μg/mL. Conclusions: With the drug seizures found with FDCK resembled in physical appearance with ketamine seizures, users might likely misuse it as ketamine. Though complicated by other drugs found, it is speculated that the two cases with higher concentration of FDCK found in blood (1.1 and 0.87 μg/mL) might have contributed to the impairment observed. •Fluorodeschloroketamine (FDCK) were detected in 74 drug seizures and 6 DUID cases.•Either alone or mixed with ketamine in drug seizures.•Multiple drugs were found in all DUID cases with 2 found with high levels of FDCK.•Users might have mistaken FDCK as a substitute of ketamine.

A method for detecting methamphetamine (MET), ketamine (KET), and morphine (MOP) molecules is presented using a reusable substrate based on SERS. The SERS substrate was prepared by etching the Au/Ag alloy film to synthesize a nanoporous Au membrane (AuNPM). By optimizing the preparation conditions and using rhodamine 6G (R6G) as an analyte, the AuNPM exhibited good SERS performance with a limit of detection (LOD) of 10 −9  mol L −1 . A competitive immunoassay category has been applied to the detection of MET, KET, and MOP. The MET, KET, and MOP antigens were functionalized on the surface of the AuNPM to specifically bind to the related drug antibodies. The Au nanoparticles (AuNPs) modified with 4-mercaptobenzoic acid (4-MBA) and antibodies against MET, KET, and MOP were used as nanotags. The 4-MBA served as the reporting molecule and drug antibodies were used to bind to free drug molecules in the target solution. The mixture of nanotags and target solution was dropped onto the antigen-modified AuNPM (antigen/AuNPM), and the free nanotags bind to the antigen/AuNPM. By comparing the SERS intensity of 4-MBA with the presence or absence of drug molecules, the drugs were qualitatively and quantitatively identified. Through this category, the LODs for detecting MET, KET, and MOP were 0.1, 1, and 1 ng mL −1 , respectively. This study proposes an effective method for constructing SERS-based detection of drug molecules with good potential for practical applications. Graphical abstract

The use of 3D-printed electrodes is reported fabricated from in-house conductive filament composed of a mixture of recycled poly (lactic acid) (rPLA), graphite (Gpt), and carbon black (CB) for fast detection of the abused drug ketamine. Firstly, the performance of these electrodes was evaluated in comparison to 3D-printed electrodes produced employing a commercially available conductive filament. After a simple pretreatment step (mechanical polishing), the new 3D-printed electrodes presented better performance than the electrodes produced from commercial filament in relation to peak-to-peak separation of the redox probe [Fe(CN) 6 ] 3- / 4- (130 mV and 759 mV, respectively), charge transfer resistance (R ct  = 1.04 ± 0.05 kΩ and 9.62 ± 0.03 kΩ, respectively), and heterogeneous rate constant (k 0  = 7.16 ± 0.05 × 10 –3  cm s −1 and 3.57 ± 0.03 × 10 –3  cm s -1 , respectively). Excellent analytical characteristics for the detection of ketamine were achieved, including wide linear range (10 to 250 μmol L -1 ), excellent sensitivity (0.024 ± 0.001 μA μmol L -1 ), low limit of detection (LOD = 0.7 μmol L -1 ), and recovery values from 82 to 115% for beverage samples (white and red wines, beer, water, and vodka) spiked with the abused drug ketamine. Graphical Abstract

The measurement of illicit drug metabolites in raw wastewater is increasingly being adopted as an approach to objectively monitor population-level drug use, and is an effective complement to traditional epidemiological methods. As such, it has been widely applied in western countries. In this study, we utilised this approach to assess drug use patterns over nine days during April 2011 in Hong Kong. Raw wastewater samples were collected from the largest wastewater treatment plant serving a community of approximately 3.5 million people and analysed for excreted drug residues including cocaine, ketamine, methamphetamine, 3,4-methylenedioxymethamphetamine (MDMA) and key metabolites using liquid chromatography coupled with tandem mass spectrometry. The overall drug use pattern determined by wastewater analysis was consistent with that have seen amongst people coming into contact with services in relation to substance use; among our target drugs, ketamine (estimated consumption: 1400–1600mg/day/1000 people) was the predominant drug followed by methamphetamine (180–200mg/day/1000 people), cocaine (160–180mg/day/1000 people) and MDMA (not detected). The levels of these drugs were relatively steady throughout the monitoring period. Analysing samples at higher temporal resolution provided data on diurnal variations of drug residue loads. Elevated ratios of cocaine to benzoylecgonine were identified unexpectedly in three samples during the evening and night, providing evidence for potential dumping events of cocaine. This study provides the first application of wastewater analysis to quantitatively evaluate daily drug use in an Asian metropolitan community. Our data reinforces the benefit of wastewater monitoring to health and law enforcement authorities for strategic planning and evaluation of drug intervention strategies.

The purpose of this study was to develop and validate a high-sensitivity methodology for identifying one of the most used drugs—ketamine. Ketamine is used medicinally to treat depression, alcoholism, and heroin addiction. Moreover, ketamine is the main ingredient used in so-called “date-rape” pills (DRP). This study presents a novel methodology for the simultaneous determination of ketamine based on the Dried Blood Spot (DBS) method, in combination with capillary electrophoresis coupled with a mass spectrometer (CE-TOF-MS). Then, 6-mm circles were punched out from DBS collected on Whatman DMPK-C paper and extracted using microwave-assisted extraction (MAE). The assay was linear in the range of 25–300 ng/mL. Values of limits of detection (LOD = 6.0 ng/mL) and quantification (LOQ = 19.8 ng/mL) were determined based on the signal to noise ratio. Intra-day precision at each determined concentration level was in the range of 6.1–11.1%, and inter-day between 7.9–13.1%. The obtained precision was under 15.0% (for medium and high concentrations) and lower than 20.0% (for low concentrations), which are in accordance with acceptance criteria. Therefore, the DBS/MAE/CE-TOF-MS method was successfully checked for analysis of ketamine in matrices other than blood, i.e., rose wine and orange juice. Moreover, it is possible to identify ketamine in the presence of flunitrazepam, which is the other most popular ingredient used in DRP. Based on this information, the selectivity of the proposed methodology for identifying ketamine in the presence of other components of rape pills was checked.

We developed, optimized and validated a fast analytical cycle using high throughput bar adsorptive microextraction and microliquid desorption (HT-BAμE-μLD) for the extraction and desorption of ketamine and norketamine in up to 100 urine samples simultaneously, resulting in an assay time of only 0.45 min/sample. The identification and quantification were carried out using large volume injection-gas chromatography-mass spectrometry operating in the selected ion monitoring mode (LVI-GC-MS(SIM)). Several parameters that could influencing HT-BAµE were assayed and optimized in order to maximize the recovery yields of ketamine and norketamine from aqueous media. These included sorbent selectivity, desorption solvent and time, as well as shaking rate, microextraction time, matrix pH, ionic strength and polarity. Under optimized experimental conditions, suitable sensitivity (1.0 μg L−1), accuracy (85.5–112.1%), precision (≤15%) and recovery yields (84.9–105.0%) were achieved. Compared to existing methods, the herein described analytical cycle is much faster, environmentally friendly and cost-effective for the quantification of ketamine and norketamine in urine samples. To our knowledge, this is the first work that employs a high throughput based microextraction approach for the simultaneous extraction and subsequent desorption of ketamine and norketamine in up to 100 urine samples simultaneously.