OBJECTIVES: To establish a method for the detection of carbamazepine and its metabolites 10,11-dihydro-10,11-epoxycarbamazepine and 10,11-dihydro-10-hydroxycarbamazepine in blood samples by liquid chromatography-tandem mass spectrometry (LC-MS/MS). METHODS: The blood samples were treated with 1-butyl-3-methylimidazolium hexafluorophosphate as an extraction solvent. The samples were extracted by ultrasound-assisted extraction and separated by ZORBAX Eclipse Plus C18, 95Å column. The mobile phase A aqueous solution containing 0.1% formic acid and 10 mmol/L ammonium acetate, and mobile phase B mixed organic solvent containing acetonitrile/methanol (V_acetonitrile∶V_methanol=2∶3) were used for gradient elution at the flow rate of 1.00 mL/min. An electrospray ion source in positive mode was used for detection in the multiple reaction monitoring. RESULTS: The linearities of carbamazepine and its metabolites 10,11-dihydro-10,11-epoxycarbamazepine and 10,11-dihydro-10-hydroxycarbamazepine in blood samples were good within the corresponding range, with correlation coefficients (r) greater than 0.995 6. The limits of detection were 3.00, 0.40 and 1.30 ng/mL, respectively. The limit of quantitation were 8.00, 1.00 and 5.00 ng/mL, respectively. The extraction recoveries ranged from 76.00% to 106.44%. The relative standard deviations of the intra-day and inter-day precisions were less than 16%. Carbamazepine and its main metabolite 10,11-dihydro-10,11-epoxycarbamazepine were detected in blood samples of death cases with a mass concentration of 2.71 μg/mL and 252.14 ng/mL, respectively. CONCLUSIONS This method has high sensitivity and good selectivity, which is suitable for the detection of carbamazepine and its metabolites in blood samples, and can be used for carbamazepine-related forensic identifications.
Chromatography, Liquid/methods* ; Tandem Mass Spectrometry ; Methanol ; Carbamazepine/analysis* ; Benzodiazepines/analysis* ; Solvents ; Chromatography, High Pressure Liquid ; Solid Phase Extraction

Objective: A method to determine chlorobenzene metabolite-p-chlorophenol in urine by solid phase extraction-gas chromatography was established. Methods: In May 2021, the urine sample was hydrolyzed at 100 ℃ for 1.5 h with 2 ml concentrated hydrochloric acid. After cooling and filtering, the sample was enriched and purified by Oasis(®)MAX 6cc SPE column. Drip washing with 0.01 mol/L hydrochloric acid solution and elution with acetonitrile, the eluent was volumized to 5 ml with acetonitrile and determined by gas chromatography, and quantify by standard curve method. Results: Calibration curve of the method was linear within the range of 1.61-80.30 μg/ml and showed good linearity with r=0.9997, the regression equation was y=1.51602x-0.10234. The determination limit was 0.17 μg/ml, and the limit of quantitation was 0.55 μg/ml. Recovery rates were between 89.3%-104.4%, the relative standard deviation (RSD) of intra-day measurements ranged from 4.3% to 6.7%, and the RSD of inter-day measurements ranged from 4.5% to 6.7%. Conclusion: This method could optimize sample pretreatment, and eliminate the interference of impurities, which is sensitive, efficient and accurate for the determination of chlorobenzene metabolite-p-chlorophenol in urine.
Acetonitriles ; Chlorophenols ; Chromatography, Gas ; Chromatography, High Pressure Liquid ; Hydrochloric Acid ; Solid Phase Extraction/methods*

BACKGROUND: Glyphosate and its salt formulations are nonselective herbicides that have been extensively used worldwide, both for residential and agricultural purposes. The possible carcinogenicity and teratogenicity of glyphosate remain to be elucidated. We developed a sensitive and high-throughput analytical method for urinary glyphosate using liquid chromatography-tandem mass spectrometry with the aim of contributing to glyphosate exposure assessment in epidemiological studies. METHODS: After urine dilution (creatinine matching dilution to 0.05 g creatinine/L), glyphosate was extracted using two types of solid phase extraction columns (SCX and NH2) with automated sample preparation instruments. The eluate was dried and dissolved in the mobile phase, followed by liquid chromatography-tandem mass spectrometry analysis. The optimized method was applied to urine samples obtained from 54 Japanese adults and children. RESULTS: The results from the validation study demonstrated good recoveries (91.0-99.6%), within- and between-run precisions (< 15%), low detection limits (0.1 μg/L), and lower limit of quantification (0.3 μg/L). The detection frequency and median concentration of the urinary glyphosate in Japanese subjects were 59% and 0.25 μg/L (0.34 μg/g creatinine). CONCLUSIONS Our reliable determination method was successful in measuring urinary glyphosate concentration. Moreover, this is the first biomonitoring report of urinary glyphosate levels in the Japanese general population.
Adult ; Aged ; Chromatography, Liquid/methods* ; Female ; Glycine/urine* ; Humans ; Male ; Middle Aged ; Solid Phase Extraction/methods* ; Tandem Mass Spectrometry/methods*

Positron emission tomography (PET) is a powerful non-invasive molecular imaging technique for the early detection, characterization, and "real-time" monitoring of disease, and for investigating the efficacy of drugs (Phelps, 2000; Ametamey et al., 2008). The development of molecular probes bearing short-lived positron-emitting radionuclides, such as ¹⁸F (half-life 110 min) or ¹¹C (half-life 20 min), is crucial for PET imaging to collect in vivo metabolic information in a time-efficient manner (Deng et al., 2019). In this regard, one of the main challenges is rapid synthesis of radiolabeled probes by introducing the radionuclides into pharmaceuticals as soon as possible before injection for a PET scan. Although many potential PET probes have been discovered, only a handful can satisfy the demand for a highly efficient synthesis procedure that achieves radiolabeling and delivery for imaging within 1-2 radioisotope half-lives. Only a few probes, such as 2-deoxy-2-[¹⁸F]fluoro-D-glucose (¹⁸F-FDG) and [¹⁸F]fluorodopa, are routinely produced on a commercial scale for daily clinical diagnosis (Grayson et al., 2018; Carollo et al., 2019).
Lab-On-A-Chip Devices ; Positron-Emission Tomography/methods* ; Radioisotopes/chemistry* ; Radiopharmaceuticals/chemical synthesis* ; Solid Phase Extraction

OBJECTIVE: To establish the solid phase extraction (SPE) with GC/MS technology for fish poisoning cases to determine five pesticides in fishpond. METHODS: By three solid phase extraction column including Oasis HLB cartridge, Bond Elut C18 and SampliQ C18, the recovery rate was compared to extract and purify five pesticides in fishpond. The effects of different kinds and dosages of eluents on extract rate were also reviewed. RESULTS Using Bond Elut C18 as solid phase extraction column and 3 mL benzene as eluent, the linear range of mass concentration of five pesticides in fishpond was 1-50 μg/mL, and the correlation coefficient was 0.996 2-0.999 6. The limit of detection was 3.4-26 μg/L and the recovery was 61.49%-102.48%. The relative standard deviations was less than or equal to 3.01%. CONCLU-SION: With high sensitivity, good accuracy and precision, SPE-GC/MS has simple and quick operation and less solvent. It can be applied to determination of five pesticides in fishpond.
Gas Chromatography-Mass Spectrometry/methods* ; Pesticides/isolation & purification* ; Solid Phase Extraction ; Solvents ; Water Pollutants, Chemical/isolation & purification*

A method was developed for the determination of ochratoxin A (OTA) in human urine by HPLC-FLD after molecularly imprinted polymer solid phase extraction (MIP-SPE) column. After the pH being adjusted to 2.5 with 0.1 mol x L(-1) HC1, sample was cleaned up with MIP-SPE column for ochratoxin A, the analyte was analyzed by high performance liquid chromatography coupled with fluorescence detection (HPLC-FLD), and finally all the positive results were confirmed by LC-MS/MS. Recoveries from urine samples spiked with OTA at levels ranging from 2 to 20 ng x mL(-1) were 90.6%-101.9%, and RSDs were 0.1%-1.6%. Sixty-five volunteers living in Beijing took part in the study, of which 5 were found containing OTA in their urine and the highest value was 0.091 ng x mL(-1). The MIP-SPE column was firstly applied to purify and concentrate OTA in human urine, this method is simple, rapid and reliable and can be used to determine the contents of OTA in human urine.
Chromatography, High Pressure Liquid ; methods ; Female ; Humans ; Male ; Molecular Imprinting ; Ochratoxins ; urine ; Polymers ; Reproducibility of Results ; Sensitivity and Specificity ; Solid Phase Extraction

Suitable pretreatment of biological samples can truly reflect the role of law of the measured components played in the body and will provide experimental evidence for the studies on metabolic process, material basis of efficacy, mechanism of action, pharmacology, toxicology and the others. Biological samples include blood, urine, hair, tears, etc. There are also many samples processing methods, such as the direct protein precipitation, liquid-liquid extraction and solid phase extraction and so on. These methods could be used alone or combined.
Animals ; Body Fluids ; chemistry ; Chemical Precipitation ; Chemistry Techniques, Analytical ; methods ; Humans ; Liquid-Liquid Extraction ; Proteins ; isolation & purification ; Solid Phase Extraction

OBJECTIVETo develop an analytical method for simultaneous determination of 6 pesticides, namely bentazone, 2,4-dichlorophenoxyacetic acid,carbofuran, carbaryl, atrazine and pentachlorophenol, in drinking water by high performance liquid chromatography-tandem mass spectrometry, and thereby to provide a reference to revise the Health Standards for Drinking Water (GB/T 5750-2006). Meanwhile, to evaluate the content of the above 6 pesticides in the drinking water samples supplied by 12 centralized water plants in Jiangsu province.

METHODSThe 10 ml water sample was acidized by hydrochloric acid to pH ≤ 2, and then concentrated by solid phase extraction cartridge and eluted with acetone. The solvent was changed into methanol after drying by nitrogen blow. The target compounds were separated by C18 column using methanol/water as mobile phase, and detected by mass spectrometry with multi-reaction-monitoring(MRM) mode. The repeatability and sensitivity of the assay were evaluated. The drinking water samples from the 12 water plants were then detected.

RESULTSIn this experimental method, the minimum detectable concentration were around 0.02-0.41 µg/L, with the recovery rate at 75%-115%, and the RSD between 2% and 10%. Under the experimental condition, there were no pesticides detected in the drinking water samples from the 12 centralized water plants.

CONCLUSIONThe method is efficient and environment-friendly, with little discharge of effluent, which could meet the requirement of the drinking water monitor.

Drinking Water ; analysis ; Pesticides ; analysis ; Solid Phase Extraction ; methods ; Tandem Mass Spectrometry ; methods ; Water Pollutants, Chemical ; analysis

Two sample pretreatment methods of pesticide residues in Panax notoginseng of Chinese traditional medicine were developed. For Method I, the residues were extracted from homogenized tissue with n-hexane-dichloromethane (6:4) by means of ultrasonication, the crude extract was purified by an Envi-carb/NH2 solid-phase extraction (SPE) column. For Method II, matrix solid-phase dispersion (MSPD) technique was used for extracting and cleaning up. The eluates were concentrated by rotary evaporation, and then were redissolved in dichloromethane prior to GC-MS determination. The determination was performed in selected ion monitoring (SIM) mode with the external calibration for quantitative analysis. Under the optimal conditions, the results indicated that the methods are easier and faster, the recoveries of method I for the spiked standards at concentration of 0.01, 0.5, and 2.0 mg x kg(-1) were 81.90%-102.10% with the relative standard deviations (RSDs) of 3.60%-7.10%. The recoveries of method II were 96.26%-104.20% with the RSDs of 3.52%-7.94%. The detection limits (S/N) for residues of pesticides were in the range of 0.48-1.34 ng x g(-1). The results indicated that these multiresidue analysis methods can meet the requirements for determination of residue pesticides and can be appropriate for trace analysis of residue pesticides in Panax notoginseng.
Analytic Sample Preparation Methods ; methods ; Gas Chromatography-Mass Spectrometry ; Hexanes ; chemistry ; Methylene Chloride ; chemistry ; Panax notoginseng ; chemistry ; Pesticide Residues ; analysis ; Solid Phase Extraction ; Solvents

OBJECTIVETo establish a method for analyzing solid phase extraction-high performance liquid chromatography-electrospray ionization tandem mass spectrometry (SPE-HPLC-ESI-MS(n)), in order to recognize and identify the main chemical constituents in Qinghuo Zhimai tablets.

METHODThe possible structures of the compounds were determined according to the structure information of compounds observed from molecular ion peaks and fragment ions in HPLC-ESI-MS(n) negative ion mode and by comparing with literature data or control samples.

RESULTThrough the comparative analysis on Qinghuo Zhimai Tablets and components of its formula, 39 chemical constituents were identified, including 7 caffeoylquinic acids, 7 iridoids, 6 diterpenoid lactones, 5 homoisoflavonoids, 13 steroidal saponins and 1 flavone glycoside.

CONCLUSIONThis study provides a simple and rapid method for identifying chemical components in Qinghuo Zhimai tablets.

Chromatography, High Pressure Liquid ; methods ; Drugs, Chinese Herbal ; chemistry ; isolation & purification ; Flavones ; chemistry ; isolation & purification ; Glycosides ; chemistry ; isolation & purification ; Iridoids ; chemistry ; isolation & purification ; Lactones ; chemistry ; isolation & purification ; Medicine, Chinese Traditional ; Molecular Structure ; Quinic Acid ; analogs & derivatives ; chemistry ; isolation & purification ; Saponins ; chemistry ; isolation & purification ; Solid Phase Extraction ; methods ; Spectrometry, Mass, Electrospray Ionization ; methods ; Tablets ; Tandem Mass Spectrometry ; methods