Rapid determination of glyphosate and glufosinate in human blood by probe electrospray ionization tandem mass spectrometry.

In forensic science, glyphosate (GLYP) and glufosinate (GLUF), a class of non-selective broad-spectrum herbicides, have been frequently encountered in many fatal poisoning and suicide cases due to their widespread availability. Therefore, it is essential to develop an effective method for detecting these compounds. Some conventional methods, such as gas chromatography-mass spectrometry (GC-MS) or liquid chromatography-mass spectrometry (LC-MS), have been reported to detect these compounds. However, these methods are not ideal for their time-consuming and non-sensitive feature. Herein, probe electrospray ionization (PESI) tandem mass spectrometry (MS/MS), a fast and sensitive technique, was applied for the determination of GLYP and GLUF in human blood, which can obtain analytical results within 0.5 min without derivatization and chromatographic separation. After protein precipitation of blood samples, the supernatant was mixed with isopropanol and ultra-pure water (1:1 v/v). Then, 8 µL of the mixture was introduced into the plastic sample plate for PESI-MS/MS analysis. The limits of detection (LODs) of the method were 0.50 µg/mL and 0.25 µg/mL for two analytes, and the limits of quantitation (LOQs) were both 1.00 µg/mL, which are higher than the concentration of reported poisoning and fatal cases. In the linear range of 1-500 µg/mL, the regression coefficients (r2) for GLYP and GLUF were over 0.99. The matrix effects ranged from 94.8 % to 119.5 %, and the biases were below 4.3 %. The recoveries ranged between 84.8 % and 107.4 %, and the biases were below 7.6 %. Meanwhile, the method was effectively utilized to detect and quantify the blood, urine, and other samples. Consequently, the results suggest that PESI-MS/MS is a straightforward, fast, and sensitive method for detecting GLUF and GLYP in forensics. In the future, PESI-MS/MS will become an indispensable technique for polar substances in grassroots units of public security where rapid detection is essential.

[Development of an analytical system for dried blood spots for forensic toxicology: a case study of five common drugs and poisons].

Dried blood spot (DBS) technology is a simple and convenient method for collecting, transporting, and storing blood samples on filter paper, and has numerous applications in the clinical, research, and public health settings. This technique is gaining popularity in the field of forensic science because it facilitates the rapid analysis of prohibited drugs in blood samples and offers significant advantages in toxicology scenarios such as drinking-driving screening, drug abuse detection, and doping detection. However, the lack of a standardized system and the fact that its stability and reliability have not been thoroughly researched and demonstrated limit its application in judicial practice in China. DBS samples can be prepared, stored, and analyzed in various ways, all of which may significantly affect the results. In this study, we developed a method based on ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) that focuses on the preparation, pretreatment, analysis, and storage of DBS samples. A thorough investigation was conducted to examine the optimal preparation conditions, including the blood spot matrix, drying technique, and preprocessing parameters, such as the solvent and extraction method. Moreover, the analytical conditions, such as the mobile phase system and elution gradient, were established to facilitate the quantitative detection of methamphetamine, lidocaine, ketamine, fentanyl, and diazepam in both DBS and whole-blood samples. The impact of storage conditions, such as the temperature, humidity, and sealing, on the analytical results of the DBS and whole-blood samples was also examined. The results showed a strong linear relationship for lidocaine and fentanyl within the range of 0.5-100 ng/mL. Similarly, methamphetamine, ketamine, and diazepam exhibited good linearity within the range of 2-100 ng/mL. The coefficients of determination (r2) ranged from 0.9983 to 0.9997, and the limits of detection ranged from 0.2 to 0.5 ng/mL, indicating a high degree of correlation and sensitivity. Stability tests demonstrated that the five target substances remained stable in the DBS for 60 days, with the measured contents deviating from the nominal values by 15%. Moreover, the measurement results of the DBS samples were highly similar to those of the whole-blood samples, with mean percentage differences of 4.44%, 3.50%, 7.66%, 5.10%, and 5.25% for fentanyl, diazepam, ketamine, lidocaine, and methamphetamine, respectively. Throughout the 60-day storage period, the maintenance of temperatures of -20 and 4 ℃, as well as sealing and dry storage, was not necessary. Room temperature was the most practical storage environment for the DBS samples. The results for each target showed very small concentration differences between the whole-blood and DBS samples, indicating that the DBS samples were suitable for drug and poison analysis in blood. Furthermore, the DBSs exhibited high quantitative consistency with the whole-blood samples, rendering them suitable matrices for preserving blood samples. Because DBS samples are easy to handle and store, they can realize the lightweight preservation of blood samples and provide a novel solution for the analysis and preservation of blood samples in public security practice. We recommend conducting comprehensive validations before utilizing DBS for analysis, particularly in terms of quantification, to ensure the judicial reliability of the results.

Application of aptamer-conjugated graphene oxide for specific enrichment of microcystin-LR in Achatina fulica prior to matrix-assisted laser desorption ionization mass spectrometry.

Microcystin-LR (MC-LR), as a hepatotoxin, can cause liver swelling, hepatitis, and even liver cancer. In this study, MC-LR aptamer (Apt-3) modified graphene oxide (GO) was designed to enrich MC-LR in white jade snail (Achatina fulica) and pond water, followed by matrix-assisted laser desorption ionization mass spectrometry (MALDI-MS) analysis. Results indicated that the Apt-3/PEG/GO nanocomposites were highly specific to MC-LR, and the detection limit of MALDI-MS was 0.50 ng/mL. Moreover, the MC-LR can be released from nanocomposites at 75°C, thus, the reuse of Apt-3/PEG/GO is realized. Real sample analysis indicated that the Apt-3/PEG/GO nanocomposites coupled with MALDI-MS were efficient in detecting trace amounts of MC-LR in real samples. With the merits of being low cost, reusable, and easy to besynthesized, this Apt-3/PEG/GO MALDI-MS is expected to be comprehensively applied by anchoring suitable aptamers for different targets.

Evaluation of Monochromatic Excitation X-ray Fluorescence Spectrometry for Rapid Thallium Detection in Biological Samples Using Animal Models.

Monochromatic excitation X-ray fluorescence (ME-XRF) spectrometry is a novel technique for trace element analysis, characterized by its simplicity, rapidity, and low cost. The objective of this study was to evaluate the applicability of ME-XRF technique for the measurement of thallium in biological samples. Acute and subacute thallium poisoning experiments were conducted to simulate various scenarios, with blood, urine, and 10 distinct organs collected. Detection was initially performed using ME-XRF technique, followed by validation with inductively coupled plasma mass spectrometry (ICP-MS). Excellent agreement between ME-XRF and ICP-MS values was demonstrated by means of paired sample t-tests and intraclass correlation coefficients. Subsequently, the practical implementation of the proposed technique was demonstrated through an actual case study. In conclusion, this study validates ME-XRF as a suitable alternative to ICP-MS for the measurement of trace heavy metals in biological samples. These efforts promote the development of simpler and faster techniques for heavy metal detection, thereby presenting novel avenues for the prevention and diagnosis of heavy metal poisoning.

[Simultaneous determination of 36 hypotensive drugs in fingerprints by ultra performance liquid chromatography-triple quadrupole composite linear ion trap mass spectrometry].

Fingerprints contain important information such as the ingredients ingested by the donor. By analyzing the characteristic components in fingerprints, the donor can be characterized, which would provide insights for investigation of a given case. This approach can also be used in the qualitative monitoring of drug intake. Therefore, the examination of hypotensive drugs in fingerprints has significant value in practical application. This study established a method based on ultra performance liquid chromatography-triple quadrupole composite linear ion trap mass spectrometry (UPLC-Q-TRAP/MS) for the simultaneous determination of 36 hypotensive drugs in fingerprints. The pre-treatment method was based on protein precipitation. A 3×3 cm filter paper was cut into pieces and placed in a 2 mL plastic centrifuge tube after fingerprint collection. Then, 0.50 mL methanol was added, followed by vortex mixing for 1 min and ultrasonic oscillation for 3 min. The filter paper was centrifuged at 12000 r/min for 5 min, and the supernatant was withdrawn for sample analysis. An ACQUITY UPLC® BEH C18 chromatographic column (100 mm×3.0 mm, 1.7 µm) was selected, with 0.01% aqueous formic acid and methanol as mobile phases for gradient elution. MS analysis involved scheduled multiple reaction monitoring-information dependent acquisition-enhanced product ion (SMRM-IDA-EPI) scanning. This method could be used to retrieve library researching during high-sensitivity analysis, which could increase the accuracy of qualitative results. The calibration curves showed good linearity in the range of 0.05-50.00 ng/fingerprint, with correlation coefficients (r) greater than 0.99 for all 36 analytes. The limits of detection and limits of quantification of the 36 hypotensive drugs were 0.001-0.045 ng/fingerprint and 0.002-0.050 ng/fingerprint, respectively. At spiked levels of 0.25, 2.50, 25.00 ng/fingerprint, the matrix effects, recoveries, intra-day precisions, and inter-day precisions of the 36 hypotensive drugs were 79.0%-119.2%, 79.3%-116.2%, 0.2%-18.3%, and 1.6%-19.1%, respectively. This method was used to detect hypotensive drugs in the fingerprints of 87 hypertensive patients, and hypotensive drug intakes were accurately detected in most cases. The established method is operationally simple, with high sensitivity and good selectivity, and it is suitable for screening and testing hypotensive drugs in fingerprints.

On-site testing of multiple drugs of abuse in urine by a miniature dual-LIT mass spectrometer.

There is an increasing need for rapid and on-site detection of emerging drugs of abuse. In this work, we developed a method using a miniature dual-LIT (linear ion trap) mass spectrometer recently developed with comprehensive tandem mass spectrometry analysis capability, for qualitative and quantitative analysis of multiple drugs of abuse. Paper-capillary spray cartridges were used with related workflow established to simplify overall analysis procedure. Quantitation of ketamine and methamphetamine was achieved by beam-type collision-induced dissociation on the miniature dual-LIT mass spectrometer and a linear concentration range of 100-5000 ng/mL was obtained. The system has been applied in analysis of real urine samples from individuals addicted to morphine and methamphetamine use. The changes of the ratio of cocaine to its metabolite benzoylecgonine were also explored to estimate the time of cocaine intaking.

Synthesis and antiproliferative activity of pterostilbene and 3'-methoxy pterostilbene Mannich base derivatives against Hela cells.

Fourteen novel pterostilbene (1) and [Formula: see text]-methoxy pterostilbene (2) Mannich base derivatives (3-16) were synthesized via the microwave-assisted Mannich reaction of 1 or 2 with various secondary amines and formaldehyde. The regioselectivity of the reaction occurred preferentially at [Formula: see text] position of the B-ring of stilbene. The biological testing results showed that all the target compounds exhibit antiproliferative activity against Hela cells from [Formula: see text]-[Formula: see text]. Compounds 1-3, 7, 11-13, and 16 displayed higher (lower [Formula: see text] values) activity than the positive control cisplatin [Formula: see text].