This paper describes a dispersive liquid–liquid microextraction (DLLME) procedure using room temperature ionic liquids (RTILs) coupled with flame atomic absorption spectrometry detection with microsample intro-ductio...This paper describes a dispersive liquid–liquid microextraction (DLLME) procedure using room temperature ionic liquids (RTILs) coupled with flame atomic absorption spectrometry detection with microsample intro-duction system capable of quantifying trace amounts of lead. In the proposed approach, ammonium pyr-rolidine dithiocarbamate (APDC) was used as a chelating agent and 1-hexyl-3-methylimmidazolium bis (trifluormethylsulfonyl)imid as an extraction solvent was dissolved in acetone as the disperser solvent. The binary solution was then rapidly injected by a syringe into the water sample containing Pb2+ complex. Some factors influencing the extraction efficiency of Pb2+ and its subsequent determination, including extraction and dispersive solvent type, pH of sample solution, concentration of the chelating agent and salt effect were inspected by a full factorial design to identify important parameters and their interactions. Next, a central composite design was applied to obtain the optimum points of the important parameters. Under the optimum conditions, the limit of detection (LOD) was 0.2 μg/L. The relative standard deviation (R.S.D) was 1.4% for 5 μg/L of Pb2+ (n = 7). The relative recovery of lead in seawater, blood, tomato and black tea samples was measured.展开更多
One of the most important tools used to evaluate kidney function in the context of chronic kidney disease or other renal function related pathologies is the exploration of glomerular filtration rate (GFR). Iohexol is ...One of the most important tools used to evaluate kidney function in the context of chronic kidney disease or other renal function related pathologies is the exploration of glomerular filtration rate (GFR). Iohexol is up to this moment a good candidate molecule for the GFR assessment since it exhibits minimum protein binding rates and minimum extra-renal clearance, being neither secreted nor reabsorbed at the tubular level. This study proposes and evaluates a new LC-MS/MS method for the iohexol determination from capillary blood, prelevated using volumetric absorbative microsampling (VAMS) systems. As an alternative to VAMS, a brand new HemaPEN■ device for micro-prelevation was also tested. A new high throughput sample preparation protocol adapted for iohexol quantification from whole blood VAMS samples was developed. The medium term stability study of iohexol in dried whole blood VAMS samples that was conducted showed a good stability of this molecule for up to 12 days. By collecting only 10 mL of blood, iohexol can be analyzed from dried whole blood VAMS samples for concentration ranges between 1 and 250 mg/mL. Due to the analyte stability in VAMS for up to 12 days, this approach might be successfully applied for GFR assessment for clinical cases allowing minimum invasiveness and even delayed analysis.展开更多
Hair analysis has been mainly used to document drug use history in abusers,drug-facilitated crime cases,doping control analysis and postmortem toxicology in the fields of forensic toxicology,clinical toxicology,and do...Hair analysis has been mainly used to document drug use history in abusers,drug-facilitated crime cases,doping control analysis and postmortem toxicology in the fields of forensic toxicology,clinical toxicology,and doping control.Hair analysis has also gained more attention in the last 30 years in China.Relevant technology has been promoted as more research has appeared concerning hair analysis,and consensus has been sought among forensic toxicologists regarding aspects such as hair decontamination treatment,detection of abused substances in hair,segmental hair analysis and interpretation of analytical results.However,there are still some limitations in the estimation of drug intake time and frequency by segmental hair analysis due to the different growth cycles evident within a bundle of hairs,the drug incorporation mechanism and sampling errors.Microsampling and imaging mass spectrometry(iMS)technology based on a single hair may be a good choice to estimate drug intake time more accurately.Analysis of hair root samples may also be used to document acute poisoning in postmortem toxicology,and the analysis of the hair shaft can document long-term use of drugs depending on the length of the hair being evaluated.展开更多
文摘This paper describes a dispersive liquid–liquid microextraction (DLLME) procedure using room temperature ionic liquids (RTILs) coupled with flame atomic absorption spectrometry detection with microsample intro-duction system capable of quantifying trace amounts of lead. In the proposed approach, ammonium pyr-rolidine dithiocarbamate (APDC) was used as a chelating agent and 1-hexyl-3-methylimmidazolium bis (trifluormethylsulfonyl)imid as an extraction solvent was dissolved in acetone as the disperser solvent. The binary solution was then rapidly injected by a syringe into the water sample containing Pb2+ complex. Some factors influencing the extraction efficiency of Pb2+ and its subsequent determination, including extraction and dispersive solvent type, pH of sample solution, concentration of the chelating agent and salt effect were inspected by a full factorial design to identify important parameters and their interactions. Next, a central composite design was applied to obtain the optimum points of the important parameters. Under the optimum conditions, the limit of detection (LOD) was 0.2 μg/L. The relative standard deviation (R.S.D) was 1.4% for 5 μg/L of Pb2+ (n = 7). The relative recovery of lead in seawater, blood, tomato and black tea samples was measured.
文摘One of the most important tools used to evaluate kidney function in the context of chronic kidney disease or other renal function related pathologies is the exploration of glomerular filtration rate (GFR). Iohexol is up to this moment a good candidate molecule for the GFR assessment since it exhibits minimum protein binding rates and minimum extra-renal clearance, being neither secreted nor reabsorbed at the tubular level. This study proposes and evaluates a new LC-MS/MS method for the iohexol determination from capillary blood, prelevated using volumetric absorbative microsampling (VAMS) systems. As an alternative to VAMS, a brand new HemaPEN■ device for micro-prelevation was also tested. A new high throughput sample preparation protocol adapted for iohexol quantification from whole blood VAMS samples was developed. The medium term stability study of iohexol in dried whole blood VAMS samples that was conducted showed a good stability of this molecule for up to 12 days. By collecting only 10 mL of blood, iohexol can be analyzed from dried whole blood VAMS samples for concentration ranges between 1 and 250 mg/mL. Due to the analyte stability in VAMS for up to 12 days, this approach might be successfully applied for GFR assessment for clinical cases allowing minimum invasiveness and even delayed analysis.
基金National Natural Science Foundation of China[grant number 81772022]Shanghai Key Laboratory of Forensic Medicine[grant number 17DZ2273200]Shanghai Forensic Service Platform[grant number 19DZ2292700].
文摘Hair analysis has been mainly used to document drug use history in abusers,drug-facilitated crime cases,doping control analysis and postmortem toxicology in the fields of forensic toxicology,clinical toxicology,and doping control.Hair analysis has also gained more attention in the last 30 years in China.Relevant technology has been promoted as more research has appeared concerning hair analysis,and consensus has been sought among forensic toxicologists regarding aspects such as hair decontamination treatment,detection of abused substances in hair,segmental hair analysis and interpretation of analytical results.However,there are still some limitations in the estimation of drug intake time and frequency by segmental hair analysis due to the different growth cycles evident within a bundle of hairs,the drug incorporation mechanism and sampling errors.Microsampling and imaging mass spectrometry(iMS)technology based on a single hair may be a good choice to estimate drug intake time more accurately.Analysis of hair root samples may also be used to document acute poisoning in postmortem toxicology,and the analysis of the hair shaft can document long-term use of drugs depending on the length of the hair being evaluated.
