Optimisation of analytical methods for tuberculosis drug detection in wastewater: A multinational study

Wastewater-based epidemiology (WBE) is a robust tool for disease surveillance and monitoring of pharmaceutical consumption. However, monitoring tuberculosis (TB) drug consumption faces challenges due to limited data availability. This study aimed to optimise methods for detecting TB drugs in treated and untreated wastewater from four African countries: South Africa, Nigeria, Kenya, and Cameroon. The limit of detection (LOD) for these drugs ranged from a minimum of 2.20 (±1.02) for rifampicin to a maximum of 2.95 (±0.79) for pyrazinamide. A parallel trend was observed concerning the limit of quantification (LOQ), with rifampicin reporting the lowest average LOQ of 7.33 (±3.44) and pyrazinamide showing the highest average LOQ of 9.81 (±2.64). The variance in LOD and LOQ values could be attributed to factors such as drug polarity. Erythromycin and rifampicin exhibited moderately polar LogP values (2.6 and 2.95), indicating higher lipid affinity and lower water affinity. Conversely, ethambutol, pyrazinamide, and isoniazid displayed polar LogP values (-0.059, -0.6, and -0.7), suggesting lower lipid affinity and greater water affinity. The study revealed that storing wastewater samples for up to 5 days did not result in significant drug concentration loss, with concentration reduction remaining below 1 log throughout the storage period. Application of the optimised method for drug detection and quantification in both treated and untreated wastewater unveiled varied results. Detection frequencies varied among drugs, with ethambutol consistently most detected, while pyrazinamide and isoniazid were least detected in wastewater from only two countries. Most untreated wastewater samples had undetectable drug concentrations, ranging from 1.21 ng/mL for erythromycin to 54.61 ng/mL for isoniazid. This variability may suggest differences in drug consumption within connected communities. In treated wastewater samples, detectable drug concentrations ranged from 1.27 ng/mL for isoniazid to 10.20 ng/mL for ethambutol. Wastewater treatment plants exhibited variable removal efficiencies for different drugs, emphasising the need for further optimisation. Detecting these drugs in treated wastewater suggests potential surface water contamination and subsequent risks of human exposure, underscoring continued research's importance.

Ion-Imprinted Polymer-Based Sensor for the Detection of Mercury Ions

In this work, the development of a novel method for the detection of mercury (II) ions in wastewater using a mercury ion-imprinted polymer (IIP) combined with a quartz crystal microbalance (QCM) is described. The IIP was successfully synthesized via the polymerization of a of a novel fluorescein- and 2-aminophenol-functionalized methacrylic acid monomer, which was noted to have high binding affinity to mercury (II) ions. This polymer was subsequently coated on a QCM chip to create an IIP-QCM sensor. This sensor was established to have high selectivity and good sensitivity to mercury (II) ions, and had a limit of detection (LOD) of 14.17 ppb, a limit of quantification (LOQ) of 42.94 ppb, a signal-to-noise ratio (S/N) of 4.29, good repeatability, and a working range of 42.94 ppb to 2 ppm. The sensor was also able to analyze tap water and wastewater samples. The IIP-QCM is, therefore, promising as a highly selective, cost-effective, and rapid mercury ion sensor for applications involving the detection of mercury in wastewater.

Quantitative analysis of drugs of abuse and cognitive enhancers in influent wastewater by means of two chromatographic methods

Sewage-based epidemiology using influent wastewater is used to estimate the consumption trends of (illicit) drugs over a short or long period of time in a subpopulation. The current study aimed to develop two separate methods for the quantitative analysis of selected drugs of abuse (DOA) and cognitive enhancers in influent wastewater using reversed-phase (RP) or hydrophilic interaction liquid chromatography (HILIC) coupled to high-resolution tandem mass spectrometry (LC-HRMS/MS). The performance of RP and HILIC column was evaluated. A simple solid phase extraction was used for sample preparation. Short runtimes of 10 and 15 min on the RP and the HILIC column, respectively, allowed sufficient throughput. A six-point calibration was used for quantification with calibration ranges between 10 and 100 ng/L for all analytes except for benzoylecgonine (BZE, 30-300 ng/L). Method validation was performed according to ICH guideline M10. Analytes such as amphetamine (AMPH), BZE, cocaethylene (CE), cocaine (COC), ethyl sulfate, 4-hydroxy-3-methoxymethamphetamine, 3,4-methylenedioxymethamphetamine (MDMA), methamphetamine, methylphenidate (MPH), and ritalinic acid (RA) were included in method development and validation. Two different column types were necessary for sufficient chromatographic resolution. The analytical setup allowed detection of all other analytes at concentration levels between 1 ng/L for methylphenidate to 10 ng/L for amphetamine. A method for the detection and quantification of DOA, cognitive enhancers, and their biomarkers in wastewater was successfully developed and validated. Moreover, six proof-of-concept samples were analyzed in which AMPH, BZE, COC, MDMA, MPH, and RA were identified and further quantified.

A wastewater-based evaluation of the effectiveness of codeine control measures in Australia

BACKGROUND AND AIM

From 1 February 2018, codeine was rescheduled from an over-the-counter (OTC) to a prescription-only medicine in Australia. We used wastewater-based epidemiology to measure changes in population codeine consumption before and after rescheduling.

METHODS

We analysed 3703 wastewater samples from 48 wastewater treatment plants, taken between August 2016 and August 2019. Our samples represented 10.6 million people, 45% of the Australian population in state capitals and regional areas in each state or territory. Codeine concentrations were determined by liquid chromatography-tandem mass spectrometry and converted to per-capita consumption estimates using the site daily wastewater volume, catchment populations and codeine excretion kinetics.

RESULTS

Average per-capita consumption of codeine decreased by 37% nationally immediately after the rescheduling in February 2018 [95% confidence interval (CI) = 35.3-39.4%] and substantially in all states between 24 and 51% (95% CI = 22.4-27.0% and 41.8-59.4%). The decrease was sustained at the lower level to August 2019. Locations with least pharmacy access decreased by 51% (95% CI = 41.7-61.7%), a greater decrease than 37% observed for those with greater pharmacy access (95% CI = 35.1-39.4%). Regional areas decreased by a smaller margin to cities (32 versus 38%, 95% CI = 30.2-34.1% versus 34.9-40.4%, respectively) from a base per-capita usage approximately 40% higher than cities.

CONCLUSION

Wastewater analysis shows that codeine consumption in Australia decreased by approximately 37% following its rescheduling as a prescription-only medicine in 2018. Wastewater-based epidemiology can be used to evaluate changes in population pharmaceutical consumption in responses to changes in drug scheduling.

Electrochemical System for Field Control of Hg2+ Concentration in Wastewater Samples

The paper presents the validation of an electrochemical procedure for on-site Hg²⁺ ions determination in wastewater samples using a modified carbon screen-printed electrode (SPE) with a complexing polymeric film based on poly(2,2'-(ethane-1,2-diylbis((2-(azulen-2-ylamino)-2-oxoethyl)azanediyl))diacetic acid) (polyL). Using metal ions accumulation in an open circuit followed by anodic stripping voltammetry, the SPE-polyL electrode presents a linear range in the range of 20 µg/L to 150 µg/L, with a limit of detection (LOD) = 6 µg/L, limit of quantification (LOQ) = 20 µg/L, and an average measurement uncertainty of 26% of mercury ions. The results obtained in situ and in the laboratory using the SPE-polyL modified electrode were compared with those obtained by the atomic absorption spectrometry coupled with the cold vapor generation standardized method, with the average values indicating excellent recovery yields.

Structure Analysis of the Interfering Substance N-methyl-2-phenylpropan-1-amine of Methamphetamine in Wastewater

OBJECTIVES

To analyze the chemical structure of the interfering substance that affects the result of methamphetamine analysis in wastewater.

METHODS

A combination of GC-MS and liquid chromatography-quadrupole time-of-flight mass spectrometry (LC-QTOF-MS) was used to analyze the mass spectrum characteristics of the interfering substance that affects the result of methamphetamine analysis and to infer its possible structure. Liquid chromatography-triple quadrupole-mass spectrometry (LC-TQ-MS) was used to confirm the control material.

RESULTS

Using LC-QTOF-MS in positive electrospray ionization (ESI⁺) mode, the mass-to-charge ratio (m/z) of quasi-molecular ion in the MS¹ mass spectrometry of interfering substance was identical to that of methamphetamine, indicating that the interfering substance was probably an isomer of methamphetamine. The MS² mass spectra obtained at three collision energies of 15 V, 30 V and 45 V were highly similar to methamphetamine, suggesting that the interfering substance contained methylamino and benzyl groups. Further analysis using GC-MS in electron impact (EI) ionization mode showed that the base peak in the mass spectrum of the interfering substance was at m/z 44. The interfering substance was confirmed to be N-methyl-2-phenylpropan-1-amine by compared with the standard reference.

CONCLUSIONS

The chemical structure of N-methyl-2-phenylpropan-1-amine is highly similar to methamphetamine, which is easy to cause interference for the detection of trace amounts of methamphetamine in wastewater using LC-TQ-MS. Therefore, in the actual analysis, the chromatographic retention time can be used to distinguish between N-methyl-2-phenylpropan-1-amine and methamphetamine.

In-Sewer Stability Assessment of Anabolic Steroids and Selective Androgen Receptor Modulators

Wastewater-based epidemiology is a potential complementary technique for monitoring the use of performance- and image-enhancing drugs (PIEDs), such as anabolic steroids and selective androgen receptor modulators (SARMs), within the general population. Assessing in-sewer transformation and degradation is critical for understanding uncertainties associated with wastewater analysis. An electrospray ionization liquid chromatography mass spectrometry method for the quantification of 59 anabolic agents in wastewater influent was developed. Limits of detection and limits of quantification ranged from 0.004 to 1.56 μg/L and 0.01 to 4.75 μg/L, respectively. Method performance was acceptable for linearity (R² > 0.995, few exceptions), accuracy (68-119%), and precision (1-21%RSD), and applicability was successfully demonstrated. To assess the stability of the selected biomarkers in wastewater, we used laboratory-scale sewer reactors to subject the anabolic agents to simulated realistic sewer environments for 12 h. Anabolic agents, including parent compounds and metabolites, were spiked into freshly collected wastewater that was then fed into three sewer reactor types: control sewer (no biofilm), gravity sewer (aerobic conditions), and rising main sewer (anaerobic conditions). Our results revealed that while most glucuronide conjugates were completely transformed following 12 h in the sewer reactors, 50% of the investigated biomarkers had half-lives longer than 4 h (mean residence time) under gravity sewer conditions. Most anabolic agents were likely subject to biofilm sorption and desorption. These novel results lay the groundwork for any future wastewater-based epidemiology research involving anabolic steroids and SARMs.

Quantifying nicotine and alcohol consumption in New Zealand using wastewater-based epidemiology timed to coincide with census

INTRODUCTION

Accurate and timely information about nicotine and alcohol consumption is needed to inform effective policy. Wastewater-based epidemiology provides an opportunity to quantify consumption, which can complement traditional data collection methods.

METHODS

Wastewater samples were collected from seven wastewater treatment plants on seven consecutive days in three regions of New Zealand during the same week as the national census (6 March 2018). Samples were analysed for nicotine and alcohol metabolites using liquid chromatography-tandem mass spectrometry. Detailed catchment maps were developed and per capita consumption calculated.

RESULTS

Observed nicotine consumption (mean 1528 ± 412 cigarettes/day/1000 people) was similar to national sales data. Observed alcohol consumption (mean 1155 ± 764 standard drinks/day/1000 people) was lower than estimated using alcohol availability data. Consumption of nicotine and alcohol was generally higher in the Bay of Plenty and Canterbury compared to Auckland, mirroring trends in the New Zealand Health Survey. Intra-regional differences were observed and the patterns could not be attributed to urbanisation alone. Nicotine consumption was consistent throughout the week whereas alcohol consumption often peaked at the weekend. Nicotine consumption was correlated with neighbourhood-deprivation. There was little correlation for alcohol.

DISCUSSION AND CONCLUSIONS

Wastewater-based epidemiology provides a quantitative dataset that complements traditional methods of investigating nicotine and alcohol consumption. Timing data collection to coincide with the census helps to account for the influence of population mobility when normalising consumption.

Monitoring Consumption of Common Illicit Drugs in Kuala Lumpur, Malaysia, by Wastewater-Cased Epidemiology

Southeast Asian countries including Malaysia play a major role in global drug trade and abuse. Use of amphetamine-type stimulants has increased in the past decade in Malaysia. This study aimed to apply wastewater-based epidemiology for the first time in Kuala Lumpur, Malaysia, to estimate the consumption of common illicit drugs in urban population. Influent wastewater samples were collected from two wastewater treatment plants in Kuala Lumpur in the summer of 2017. Concentrations of twenty-four drug biomarkers were analyzed for estimating drug consumption. Fourteen drug residues were detected with concentrations of up to 1640 ng/L. Among the monitored illicit drugs, 3,4-methylenedioxy-methamphetamine (MDMA) or ecstasy had the highest estimated per capita consumptions. Consumption and dose of amphetamine-type stimulants (methamphetamine and MDMA) were both an order of magnitude higher than those of opioids (heroin and codeine, methadone and tramadol). Amphetamine-type stimulants were the most prevalent drugs, replacing opioids in the drug market. The prevalence trend measured by wastewater-based epidemiology data reflected the shift to amphetamine-type stimulants as reported by the Association of Southeast Asian Nations Narcotics Cooperation Center. Most of the undetected drug residues were new psychoactive substances (NPSs), suggesting a low prevalence of NPSs in the drug market.

Simultaneous Determination of Pharmaceuticals by Solid-phase Extraction and Liquid Chromatography-Tandem Mass Spectrometry: A Case Study from Sharjah Sewage Treatment Plant

The present work describes the optimization and validation of a highly selective and sensitive analytical method using solid phase extraction and liquid chromatography tandem mass spectrometry (SPE LC-MS/MS) for the determination of some frequently prescribed pharmaceuticals in urban wastewater received and treated by Sharjah sewage treatment plant (STP). The extraction efficiency of different SPE cartridges was tested and the simultaneous extraction of pharmaceuticals was successfully accomplished using hydrophilic-lipophilic-balanced reversed phase Waters^® Oasis HLB cartridge (200 mg/ 6 mL) at pH 3. The analytes were separated on an Aquity BEH C18 column (1.7 µm, 2.1 mm × 150 mm) using gradient elution and mass spectrometric analysis were performed in multiple reactions monitoring (MRM) selecting two precursor ions to produce ion transition for each pharmaceutical using positive electrospray ionization (+ESI) mode. The correlation coefficient values in the linear calibration plot for each target compound exceeded 0.99 and the recovery percentages of the investigated pharmaceuticals were more than 84%. Limit of detection (LOD) varied between 0.1–1.5 ng/L and limit of quantification (LOQ) was 0.3–5 ng/L for all analytes. The precision of the method was calculated as the relative standard deviation (RSD%) of replicate measurements and was found to be in the ranges of 2.2% to 7.7% and 2.2% to 8.6% for inter and intra-day analysis, respectively. All of the obtained validation parameters satisfied the requirements and guidelines of analytical method validation.

Analysis of N,N-dimethylamphetamine in wastewater - a pyrolysis marker and synthesis impurity of methamphetamine

The increased availability of high purity crystalline methamphetamine (MA) in Australia raised concerns because of high dosages and its potential consumption through inhalation. The present work investigates the possibility of using wastewater levels of N,N-dimethylamphetamine (DMA), a pyrolysis by-product, as an indirect indicator of MA smoking. A dedicated liquid chromatography quadrupole-time-of-flight mass spectrometry (LC-QToF-MS) method was set up to detect and quantify DMA in wastewater samples. Wastewater samples were collected from 8 locations across Australia during the period 2011-2016. Data about the abundance of DMA in MA seizures as well as in residues from drug paraphernalia were obtained from forensic laboratories in Australia. DMA/MA ratios measured in wastewater ranged from 0.0001 to 0.09 (median 0.007). DMA/MA ratios in bulk seizures are generally below 0.0025, with a median value of 0.0004, whilst residues in paraphernalia ranged from 0.031 to 3.37. DMA/MA ratios in wastewater decreased between 2011 and 2016, in parallel to an increase in MA loads. Furthermore, wastewater analyses highlighted a strong positive correlation between DMA/MA ratios and per capita MA use (Pearson's correlation ρ= 0.61, p-value <0.001). Nonetheless, geographical specificities could be highlighted between the investigated locations. The obtained data could help authorities detect hot spots of drug use as well as to plan specific intervention campaigns to tackle the issue. In future, simultaneous analysis of DMA and MA in both wastewater and seizures could improve our understanding about MA use and its consumption patterns.

Potential impact of the sewer system on the applicability of alcohol and tobacco biomarkers in wastewater-based epidemiology

Understanding the actual consumption of alcohol and tobacco in the population is important for forming public health policy. For this purpose, wastewater-based epidemiology has been applied as a complementary method to estimate the overall alcohol and tobacco consumption in different communities. However, the stability of their consumption biomarkers - ethyl sulfate, ethyl glucuronide, cotinine, and trans-3'-hydroxycotinine - in the sewer system has not yet been assessed. This study aimed to conduct such assessment using sewer reactors mimicking conditions of rising main, gravity sewer, and wastewater alone, over a 12-hour period. The results show that cotinine and trans-3'-hydroxycotinine are relatively stable under all sewer conditions while ethyl sulfate was only stable in wastewater alone and gradually degraded in rising main and gravity sewer conditions. Ethyl glucuronide quickly degraded in all reactors. These findings suggest that cotinine and trans-3'-hydroxycotinine are good biomarkers to estimate tobacco consumption; ethyl sulfate may be used as a biomarker to estimate alcohol consumption, but its in-sewer loss should be accounted for in the calculation of consumption estimates. Ethyl glucuronide, and probably most of glucuronide compounds, are not suitable biomarkers to be used in wastewater-based epidemiology due to their in-sewer instability.

Using Monte Carlo simulation to assess variability and uncertainty of tobacco consumption in a city by sewage epidemiology

OBJECTIVE

To use Monte Carlo simulation to assess the uncertainty and variability of tobacco consumption through wastewater analysis in a city.

METHODS

A total of 11 wastewater treatment plants (WWTPs) (serving 2.2 million people; approximately 83% of urban population in Dalian) were selected and sampled. By detection and quantification of principal metabolites of nicotine, cotinine (COT) and trans-3'-hydroxycotinine (OH-COT), in raw wastewater, back calculation of tobacco use in the population of WWTPs can be realised.

RESULTS

COT and OH-COT were detected in the entire set of samples with an average concentration of 2.33 ± 0.30 and 2.76 ± 0.91 µg/L, respectively. The mass load of absorbed NIC during the sampling period ranged from 0.25 to 4.22 mg/day/capita with an average of 1.92 mg/day/capita. Using these data, we estimated that smokers in the sampling area consumed an average of 14.6 cigarettes per day for active smoker. Uncertainty and variability analysis by Monte Carlo simulation were used to refine this estimate: the procedure concluded that smokers in Dalian smoked between 10 and 27 cigarettes per day. This estimate showed good agreement with estimates from epidemiological research.

CONCLUSIONS

Sewage-based epidemiology may be a useful additional tool for the large-scale monitoring of patterns of tobacco use. Probabilistic methods can be used to strengthen the reliability of estimated use generated from wastewater analysis.

Challenges of surveying wastewater drug loads of small populations and generalizable aspects on optimizing monitoring design

AIMS

Quantifying illicit drug loads through wastewater analysis (WWA) is an alternative approach to estimating population drug use. This study investigated the variability of daily drug loads in wastewater and their relationships to environmental factors over an extended period to: (i) explore the suitability of WWA in small populations and (ii) optimize the monitoring design for future studies.

DESIGN, SETTING, PARTICIPANTS

Daily wastewater samples (n = 1369 consecutive days) from a German village with approximately 7160 inhabitants.

MEASUREMENTS

Samples were analysed for cocaine and benzoylecgonine with liquid chromatography-tandem mass spectrometry. Time-series analysis was used to explore the effects of weather and other factors on daily cocaine loads. Subsampling was used to assess monitoring design.

FINDINGS

Cocaine loads [mean = 652 mgCOC /day, standard deviation (SD) = 498 mgCOC /day] increased over the study period, with higher values during winter and spring. Despite high day-to-day variation, loads were significantly higher during weekends [+161 mgCOC /day, 95% confidence interval (CI) = 115-207 mgCOC /day, P < 10(-4) ] and days with frost (+114 mgCOC /day, 95% CI = 6-223 mgCOC /day, P = 0.039) or snow (+150 mgCOC /day, 95% CI = 46-253 mgCOC /day, P = 0.005). Annual means estimated from 1-week periods were subject to approximately 60% relative error. Increasing sample size and changing sampling from consecutive days to stratified random decreased this uncertainty.

CONCLUSIONS

Day-to-day variation and seasonality of drug loads from the few long-term wastewater studies available to date suggest that up to 56 stratified random samples are required to obtain reliable (expected uncertainty around 10%) annual estimates of drug loads. Successfully assessing changes in consumption patterns or relationships to external factors requires larger sample sizes than estimating annual means, which holds true for high-prevalence drugs in small communities and low-prevalence drugs in big cities.

The spatial epidemiology of cocaine, methamphetamine and 3,4-methylenedioxymethamphetamine (MDMA) use: a demonstration using a population measure of community drug load derived from municipal wastewater

AIMS

To determine the utility of community-wide drug testing with wastewater samples as a population measure of community drug use and to test the hypothesis that the association with urbanicity would vary for three different stimulant drugs of abuse.

DESIGN AND PARTICIPANTS

Single-day samples were obtained from a convenience sample of 96 municipalities representing 65% of the population of the State of Oregon.

MEASUREMENTS

Chemical analysis of 24-hour composite influent samples for benzoylecgonine (BZE, a cocaine metabolite), methamphetamine and 3,4-methylenedioxymethamphetamine (MDMA). The distribution of community index drug loads accounting for total wastewater flow (i.e. dilution) and population are reported.

FINDINGS

The distribution of wastewater-derived drug index loads was found to correspond with expected epidemiological drug patterns. Index loads of BZE were significantly higher in urban areas and below detection in many rural areas. Conversely, methamphetamine was present in all municipalities, with no significant differences in index loads by urbanicity. MDMA was at quantifiable levels in fewer than half the communities, with a significant trend towards higher index loads in more urban areas. CONCLUSION; This demonstration provides the first evidence of the utility of wastewater-derived community drug loads for spatial analyses. Such data have the potential to improve dramatically the measurement of the true level and distribution of a range of drugs. Drug index load data provide information for all people in a community and are potentially applicable to a much larger proportion of the total population than existing measures.