Purpose In forensics, entomological specimens can be used as additional/alternative matrices to d... more Purpose In forensics, entomological specimens can be used as additional/alternative matrices to detect xenobiotics when human specimens are limited in their application. Despite some advantages over implementing putrefied human remains, most medico-legal laboratories do not include entomotoxicological procedures as routine analytical methods. We thus applied two authentic cases to evaluate necrophagous larvae’s potential as complementary matrices for toxicological analysis after extensive postmortem decomposition. Methods Larvae and postmortem human samples, including hair, stomach contents, pericardial fluid, liver, lung, and skeletal muscle, were collected at autopsy. Samples were analyzed by liquid chromatography–tandem mass spectrometry and liquid chromatography–quadrupole time-of-flight mass spectrometry for pharmaceutical substances, illicit drugs, and new psychoactive substances, including synthetic cannabinoids, benzodiazepines, new synthetic opioids, and stimulants. Results...
A high volume of fluid can strongly reduce a drug's concentration in urine. Therefore, to det... more A high volume of fluid can strongly reduce a drug's concentration in urine. Therefore, to detect diluted samples the concentration of creatinine in urine is determined during testing drugs of abuse. If the concentration is below 20 mg creatinine/dL urine, the urine sample is usually rejected for drug testing. It should be examined whether creatine or creatinine ingestion can mask urine dilution by increasing the creatinine concentration. A total of 18 subjects drank 1.3 L of water and 0.2 L of orange juice on each of the three testing days: 1. without creatine, 2. with 20 g of creatine, 3. with 20 g of creatine following incubation for four days in orange juice at room temperature; an acidic environment should promote conversion of creatine to creatinine. The lowest creatinine concentrations in urine were observed on average two hours after fluid intake. At that time, ingestion of fluid without creatine, with creatine, and with creatine (ine)-orange juice mixture resulted in mean values of 11.6, 22.5, and 28.3 mg creatinine/dL urine, respectively. It can be concluded that ingestion of creatine or creatinine can increase the concentration of creatinine in urine and thus mask dilution of a sample. The conversion of creatine in orange juice further increases availability of creatinine as it is obvious from urine creatinine concentration. Therefore, creatine ingestion during drug testing will give rise to negative results due to matrix adulteration. In a case of suspected creatine supplementation, the creatine content of the sample should be determined in addition to creatinine.
One of the major challenges of testing drugs of abuse is the detection of highly diluted urine sa... more One of the major challenges of testing drugs of abuse is the detection of highly diluted urine samples. The ingestion of a large amount of fluid can considerably reduce the concentration of substances, possibly resulting in inaccurate drug testing. For detection, determination of urinary creatinine is a widely established procedure. In this study, results from the most popular methods, including photospectrometry (Jaffe) and liquid chromatography-tandem mass spectrometry (LC-MS/MS), have been compared regarding 327 urine abstinence control samples. Since samples with creatinine concentrations close to the cut-off of 20 mg/dL are of particular interest, only samples below 50 mg/dL were considered. Results revealed a close correlation of creatinine concentrations by both analytical methods with an R2 value of 0.9005. A mean concentration difference of 3.30 ± 3.45 mg/dL was observed, indicating a moderate underestimation by the Jaffe reaction. Graphical analyses showed high accordance between both methods with only a few outliers. Due to easy handling and for economic reasons, the spectrometric method is often preferred over LC-MS/MS. For urine samples with creatinine concentrations close to the cut-off, confirmation through a second method should be performed to avoid a possible disadvantage or even severe consequences for the respective individual. It is recommended that each laboratory establishes a reliable verification method.
Highly diluted urine is among the most commonly observed factors affecting the validity of urine ... more Highly diluted urine is among the most commonly observed factors affecting the validity of urine testing for drug abuse. A minimum creatinine concentration of 20 mg/dL urine has been proposed as a marker for dilution of a urine sample. This study investigates the effect of water consumption on creatinine concentration, as well as its effect on specific gravity and osmolality. In this study, 22 subjects (17 women and 5 men) were included to determine the influence of sex and weight on the impact of excessive water consumption on these markers of urine dilution. The subjects consumed 0.5 L, 1.0 L, and 1.5 L of water, respectively, within 15 minutes. The mean minimum creatinine concentrations (Jaffé reaction) for the void 2 hours after fluid intake were 60.4 mg/dL, 15.8 mg/dL, and 10.9 mg/dL for the respective ingested volumes of water. Mean creatinine concentrations excreted by men were significantly higher than those excreted by women. Participants with a weight below 60 kg tended to...
Purpose In forensics, entomological specimens can be used as additional/alternative matrices to d... more Purpose In forensics, entomological specimens can be used as additional/alternative matrices to detect xenobiotics when human specimens are limited in their application. Despite some advantages over implementing putrefied human remains, most medico-legal laboratories do not include entomotoxicological procedures as routine analytical methods. We thus applied two authentic cases to evaluate necrophagous larvae’s potential as complementary matrices for toxicological analysis after extensive postmortem decomposition. Methods Larvae and postmortem human samples, including hair, stomach contents, pericardial fluid, liver, lung, and skeletal muscle, were collected at autopsy. Samples were analyzed by liquid chromatography–tandem mass spectrometry and liquid chromatography–quadrupole time-of-flight mass spectrometry for pharmaceutical substances, illicit drugs, and new psychoactive substances, including synthetic cannabinoids, benzodiazepines, new synthetic opioids, and stimulants. Results...
A high volume of fluid can strongly reduce a drug's concentration in urine. Therefore, to det... more A high volume of fluid can strongly reduce a drug's concentration in urine. Therefore, to detect diluted samples the concentration of creatinine in urine is determined during testing drugs of abuse. If the concentration is below 20 mg creatinine/dL urine, the urine sample is usually rejected for drug testing. It should be examined whether creatine or creatinine ingestion can mask urine dilution by increasing the creatinine concentration. A total of 18 subjects drank 1.3 L of water and 0.2 L of orange juice on each of the three testing days: 1. without creatine, 2. with 20 g of creatine, 3. with 20 g of creatine following incubation for four days in orange juice at room temperature; an acidic environment should promote conversion of creatine to creatinine. The lowest creatinine concentrations in urine were observed on average two hours after fluid intake. At that time, ingestion of fluid without creatine, with creatine, and with creatine (ine)-orange juice mixture resulted in mean values of 11.6, 22.5, and 28.3 mg creatinine/dL urine, respectively. It can be concluded that ingestion of creatine or creatinine can increase the concentration of creatinine in urine and thus mask dilution of a sample. The conversion of creatine in orange juice further increases availability of creatinine as it is obvious from urine creatinine concentration. Therefore, creatine ingestion during drug testing will give rise to negative results due to matrix adulteration. In a case of suspected creatine supplementation, the creatine content of the sample should be determined in addition to creatinine.
One of the major challenges of testing drugs of abuse is the detection of highly diluted urine sa... more One of the major challenges of testing drugs of abuse is the detection of highly diluted urine samples. The ingestion of a large amount of fluid can considerably reduce the concentration of substances, possibly resulting in inaccurate drug testing. For detection, determination of urinary creatinine is a widely established procedure. In this study, results from the most popular methods, including photospectrometry (Jaffe) and liquid chromatography-tandem mass spectrometry (LC-MS/MS), have been compared regarding 327 urine abstinence control samples. Since samples with creatinine concentrations close to the cut-off of 20 mg/dL are of particular interest, only samples below 50 mg/dL were considered. Results revealed a close correlation of creatinine concentrations by both analytical methods with an R2 value of 0.9005. A mean concentration difference of 3.30 ± 3.45 mg/dL was observed, indicating a moderate underestimation by the Jaffe reaction. Graphical analyses showed high accordance between both methods with only a few outliers. Due to easy handling and for economic reasons, the spectrometric method is often preferred over LC-MS/MS. For urine samples with creatinine concentrations close to the cut-off, confirmation through a second method should be performed to avoid a possible disadvantage or even severe consequences for the respective individual. It is recommended that each laboratory establishes a reliable verification method.
Highly diluted urine is among the most commonly observed factors affecting the validity of urine ... more Highly diluted urine is among the most commonly observed factors affecting the validity of urine testing for drug abuse. A minimum creatinine concentration of 20 mg/dL urine has been proposed as a marker for dilution of a urine sample. This study investigates the effect of water consumption on creatinine concentration, as well as its effect on specific gravity and osmolality. In this study, 22 subjects (17 women and 5 men) were included to determine the influence of sex and weight on the impact of excessive water consumption on these markers of urine dilution. The subjects consumed 0.5 L, 1.0 L, and 1.5 L of water, respectively, within 15 minutes. The mean minimum creatinine concentrations (Jaffé reaction) for the void 2 hours after fluid intake were 60.4 mg/dL, 15.8 mg/dL, and 10.9 mg/dL for the respective ingested volumes of water. Mean creatinine concentrations excreted by men were significantly higher than those excreted by women. Participants with a weight below 60 kg tended to...
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