[Identification of the relative age of iron gall ink in handwriting by capillary electrophoresis using the Fe(â ¡)/Fe(â ¢) ratio].

Identifying the relative age of iron gall ink in the handwriting on a questioned file is highly significant for court science, because it serves as important evidence for solving criminal cases and in confirming the authenticity of historical documents. This is because many criminal cases involve analysis of forged documents to conclude whether an entire document is as old as purported, or whether the entire text in the document was written at the same time. In this paper, a novel approach based on capillary electrophoresis (CE) to estimate the relative age of iron gall ink-written texts is discussed. Two kinds of chelating agents, 1,10-phen and CDTA, were used for the simultaneous determination of Fe(Ⅱ) and Fe(Ⅲ) by CE. The stability constants of ï¼»Fe(Ⅱ)-(phen)3ï¼½2+ and ï¼»Fe(Ⅱ)-CDTAï¼½2- complexes are log ß 3=21.3 and log K=18.2, respectively, while the corresponding values of ï¼»Fe(Ⅲ)-(phen)3ï¼½3+ and ï¼»Fe(Ⅲ)-CDTAï¼½- complexes are log ß 3=14.1 and log K=29.3. First, specific binding between the two kinds of chelating agents and the ferrous/ferric ions was investigated. The results confirmed specific binding between Fe(Ⅱ) and 1,10-phen as well as that between Fe(Ⅲ) and CDTA. Preliminary studies also showed that Fe(Ⅱ) in the iron gall ink was relatively stable in the ink tank due to the low pH of commercial inks; hence, the oxidation of Fe(Ⅱ) in the tank was considered to be negligible. However, when the gall ink was exposed on a paper, sulfuric acid in the ink was gradually consumed by the cellulose of paper, thus causing gradual oxidation of Fe(Ⅱ) in the written text. Changes in the peak area ratio of Fe(Ⅱ) and Fe(Ⅲ) with aging were monitored: the older the ink in the writing, the smaller is the Fe(Ⅱ)/Fe(Ⅲ) ratio. Hence, the Fe(Ⅱ)/Fe(Ⅲ) ratio could be used for estimating the relative age of iron gall ink in writing. The Fe(Ⅱ)/Fe(Ⅲ) ratio was determined by CE, and the ratio extracted from the questioned handwriting ink was compared with that extracted from the entire document to confirm whether the entire text written at the same time. The keys to the success of this technique are establishing a suitable procedure for extracting the Fe(Ⅱ) and Fe(Ⅲ) species in the handwriting ink and a CE separation procedure. The optimized sample pretreatment procedure is as follows: (1) an ink-drawn line of 1 cm length was cut and placed in a 2 mL Eppendorf tube; (2) then, 0.5 mL of 5.0 mmol/L 1,10-phen was added to the EP tube for chelation with Fe(Ⅱ), and the mixture was subjected to vibration on a vortex mixer; (3) within 60 s, 0.5 mL of 20 mmol/L CDTA was added to the sample tube for chelation with Fe(Ⅲ); (4) the tube was strongly vibrated for 10 min on a vortex mixer; (5) after centrifugation at 10000 r/min for 15 min, the supernatant was decanted into another tube for CE analysis. The optimized conditions for the CE analysis are as follows: 100 mmol/L of pH 9.2 H3BO3-Na2B4O7 buffer, 20 kV applied voltage, sample injection (1.379 kPa, 5s), fused-silica capillary dimensions 40.2 cm×75 µm i.d. (30 cm to the detector), and 254 nm detection wavelength. Meanwhile, small amounts of 1,10-phen and CDTA were added to the buffer solution to ensure stability of the formed complexes during the CE run in the capillary and to maintain the metal ions in their original oxidation state. Finally, two kinds of iron gall ink samples were tested to evaluate the applicability of the developed method. The Fe(Ⅱ)/Fe(Ⅲ) ratios of ink sample 1 and ink sample 2 changed from 1.79 to 0.45 and from 2.67 to 0.3, respectively, from the 1st day to the 75th day after writing. The results demonstrate that the developed method can be used to highlight fraudulent insertion of information and provide important guidance for the forensic analysis of the relative age of gall ink in handwriting.

Application of a validated UHPLC-MS/MS method for 28 fentanyl-analogue and novel synthetic opioids in whole blood in authentic forensic cases.

The abuse of fentanyl and its analogues, which are potent, short-acting, synthetic narcotic analgesics, has become a major issue. Many cases containing fentanyl-analogue and novel synthetic opioids have also been reported. Hence, we report the determination of fentanyl, fentanyl-analogue and novel synthetic opioids in whole blood by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The method is characterized by the use of a simple, fast and inexpensive liquid-liquid extraction (LLE) for sample preparation, a rapid run time (8 min) and a low required volume of whole blood (100 µl). The limits of detection (LODs) ranged from 0.005 to 0.03 ng/ml, and the lower limits of quantitation (LLOQs) ranged from 0.05 to 0.2 ng/ml. The method was shown to be liner over a concentration range of 0.2-40 ng/ml for fentanyl, norfentanyl and norcarfentanil and 0.05-40 ng/ml for all other target analytes. Recoveries were within the range of 72.09%-103.22%, and the matrix effects were in the 67.95%-113.32% range. Moreover, the method was applied to the detection and quantification of fentanyl and its analogues in whole blood from real forensic cases. This methodology has great potential for use in the determination of fentanyl and its analogues in forensic cases.

Alcohol consumption or contamination: A preliminary study on the determination of the ethanol origin by stable carbon isotope analysis.

The origin of ethanol detected in bio-samples whether it be from the consumption of alcoholic beverages or contamination with disinfectants has been questioned in court cases in China recently. The stable carbon isotope naturally occurs in carbon-containing compounds and can help determine the origin of the compound in question. In total, 42 types of beers and 11 types of disinfectants were analyzed by gas chromatography-isotope ratio mass spectrometry. Consumption and contamination experiments were carried out with 6 volunteers. The δ13C values of ethanol ranged from -29.51‰ to -18.36‰ for the beer samples, which reflected the botanical features of C3 plants or mixtures of C3 and C4 plants. The δ13C values of ethanol ranged from -17.7‰ to -14.4‰ for disinfectants, which reflected the different origins of ethanol in disinfectants from those in beer. The δ13C value did not change in vivo after being consumed within the time limit used in this study. These characteristics of the δ13C values will facilitate to interpret whether the ethanol detected in bio-samples originated from consumption or contamination.

Phosphine Analysis in Postmortem Specimens Following Inhalation of Phosphine: Fatal Aluminum Phosphide Poisoning in Children.

Phosphine is an insecticide for the fumigation of grains, animal feed, and leaf-stored tobacco, and it was used as a rodenticide in bulk grain stores. Phosphine poisoning may occur after accidental inhalation of phosphine, sometimes leading to death. Analysis of phosphine and its metabolites in postmortem specimens from seven fatal cases was conducted in this study, as well as postmortem specimens collected from rabbits exposed to phosphine. The total phosphine in postmortem specimens was analyzed by headspace gas chromatography coupled with mass spectrometry. Diagnosis of aluminum phosphide poisoning was made after postmortem toxicological analysis and confirmed by police investigation. The deaths of the children occurred after inhalation of phosphine generated from aluminum phosphide contacting moisture in the air in all seven fatal cases. The concentration of total phosphine in the biological fluids and tissues of victims ranged from 0.2 to 4.7 µg/mL (µg/g). Animal experiments demonstrated that the phosphine generated from aluminum phosphide could rapidly cause death. The toxicological analysis of postmortem specimens provides useful information in diagnosis of aluminum phosphide poisoning in forensic science. As an important fumigation pesticide, aluminum phosphide deserves special attention, especially since there is no specific antidote and there is a high fatality rate.

MALDI-TOF MS as a Novel Tool for the Estimation of Postmortem Interval in Liver Tissue Samples.

Estimation of the postmortem interval (PMI) is a complicated task in forensic medicine, especially during homicide and unwitnessed death investigations. Many biological, chemical, and physical indicators can be used to determine the postmortem interval, but most are not accurate. Here, we present a novel matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) method that can be used for the estimation of PMI using molecular images and multivariate analyses. In this study, we demonstrate that both rat and human liver tissues of various PMIs (0, 2, 4, and 6days) can be discriminated using MALDI imaging and principal component analysis (PCA). Using genetic algorithm (GA), supervised neural network (SNN), and quick classifier (QC) methods, we built 6 classification models, which showed high recognition capability and good cross-validation. The histological changes in all the samples at different time points were also consistent with the changes seen in MALDI imaging. Our work suggests that MALDI-TOF MS, along with multivariate analysis, can be used to determine intermediate PMIs.

Determination of arsenic and lead in single hair strands by laser ablation inductively coupled plasma mass spectrometry.

The purpose of this study was to develop matrix-matched hair standards and a LA-ICP-MS technique for determination of the As and Pb in a single human hair using single spot scan mode. These results could subsequently be used to infer when the element entered the body. This study was conducted in two parts. First, a method was developed and validated for the elemental analysis of hair by LA-ICP-MS. A calibration strategy in LA-ICP-MS was developed using prepared matrix-matched laboratory hair standards doped with analytes of interest at a defined concentration. The use of hair strand standards enables calibration curves to be obtained by plotting the analyte ion (M+) intensity normalized to34S+(the ratio M+/34S+) as a function of the concentration determined by ICP-MS of the acidic digests. The linear correlation coefficients (R2) of the calibration curves for the analytes As and Pb were typically between 0.9970 and 0.9998, respectively. Second, an actual hair was measured using the developed method. The spatial distribution of As along the hair was observed in a hair sample from a leukaemia patient treated with arsenic trioxide (As2O3). The actual and estimated times over which the drug entered the body were compared and discussed.

Biomonitoring of 33 Elements in Blood and Urine Samples from Coastal Populations in Sanmen County of Zhejiang Province.

OBJECTIVE: To determine the normal reference values of 33 elements, Ag, Al, As, Au, B, Ba, Be, Ca, Cd, Co, Cr, Cs, Cu, Fe, Ga, Hg, Li, Mg, Mn, Mo, Ni, Pb, Rb, Sb, Se, Sr, Th, Ti, Tl, U, V, Zn and Zr, in the blood and urine samples from the general population in Sanmen County of Zhejiang province, a typical coastal area of eastern China. METHODS: The 33 elements in 272 blood and 300 urine samples were determined by inductively coupled plasma-mass spectrometry (ICP-MS). The normality test of data was conducted using SPSS 17.0 Statistics. The data was compared with other reports. RESULTS: The normal reference values of the 33 elements in the blood and urine samples from the general population in Sanmen County were obtained, which of some elements were found to be similar with other reports, such as Co, Cu, Mn and Sr, while As, Cd, Hg and Pb were generally found to be higher than those previously reported. There was a wide variation between the reports from different countries in blood Ba. CONCLUSION: The normal reference values of the 33 elements in the blood and urine samples from the general population in Sanmen County are established, and successfully applied to two poisoning cases.

Anticoagulant rodenticide intoxication in east China: a three-year analysis.

The study was designed to analyze the incidence and pattern of anticoagulant rodenticide intoxication in east China and to discuss strategies of diagnosis based on laboratory analysis experience. A total of 117 patients with anticoagulant rodenticide poisoning confirmed by toxicological analysis in east China were included in this study from 2011 to 2013. The mean concentration of anticoagulant rodenticide, age, and gender of these patients, as well as the mode and type of poisoning, were discussed. The age ranged from less than 1 to 80 years with the feeble preponderance of males (M = 53.0%, F = 47.0%). The 0-9 age group covered the largest ratio of these anticoagulant rodenticide poisoning patients. Accidental or voluntary ingestion seems to be the most common cause of intoxication, with still the poisoning cause being unknown for a large number of positive analyses. Bromadiolone was the most commonly observed anticoagulant rodenticide found in the biological samples, followed by brodifacoum. The concentrations of bromadiolone and brodifacoum that were detected in the first collected whole blood from each patient ranged from 1 to 878 ng/mL (mean 97.9 ng/mL) and from 0.5 to 1566 ng/mL (mean 225.1 ng/mL), respectively. The data analysis shows a high incidence of anticoagulant rodenticide poisoning without awareness of the poisoned subjects, clearly emphasizing the need for toxicological analysis in patients with vitamin K-dependent coagulation disorder and restriction on availability of anticoagulant rodenticide.

Chlorpyrifos Determined in Human Blood by UPLC-MS/MS and Its Application in Poisoning Cases.

OBJECTIVE: To determine the chlorpyrifos in human blood by liquid chromatography-tandem mass spectrometry and to validate its application in poisoning cases. METHODS: The samples were extracted by a simple one-step protein precipitation procedure. Chromatography was performed on a Capcell Pack C18 MGII column (250 mm x 2.0 mm, 5 µm) using an isocratic elution of solvent A (0.1% formic acid-water with 2 mmol/L ammonium acetate) and solvent B (methanol with 2 mmol/L ammonium acetate) at 5:95 V:V). RESULTS: The linear ranged from 5 to 500 ng/mL (r = 0.998 7). The limit of detection (LOD) and the lower limit of quantification (LLOQ) were 2 ng/mL and 4 ng/mL, respectively. For this method, the precision and accuracy of intra-day and inter-day were < 10% and 97.44%-101.10%, respectively. The results in stability test of long-term frozen were satisfied. The matrix effect, recovery and process efficiency were 64.97%-86.81%, 76.70%-85.52%, and 55.57%-66.58%, respectively. CONCLUSION: This method can provide a rapid approach to chlorpyrifos extraction and determination in toxicological analysis of forensic and clinical treatment.

[Normal Range of 33 Elements in Blood Samples from General Population in Hunan Province].

OBJECTIVE: To determine the normal range of the 33 elements (Li, Be, B, Mg, Al, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, As, Se, Rb, Sr, Zr, Mo, Ag, Cd, Sb, Cs, Ba Au, Hg, Tl, Pb, Th and U) in human whole blood of general population in Hunan province. METHODS: Blood samples were analyzed by inductively coupled plasma-mass spectrometry (ICP-MS) to determine the normal range. The influences of district, gender and age to the element content in blood samples were also observed. RESULTS: The normal range of 33 elements in blood samples from general population in Hunan province were obtained. Gender was shown to statistically influence the concentrations of B, Mg, Ca, Ti, Mn, Fe, Co, Cu, Zn, As, Se, Rb, Sr, Ag, Cd, Cs, Hg and Pb (P < 0.05), while age was shown to influence the concentrations of Co, Ni, Cs and Hg in women (P < 0.05) as well as Cu, Se and Hg in men (P < 0.05). CONCLUSION: Although there are variables in different districts, the normal ranges of trace element in blood of the four cities in Hunan province are established.

Elements concentrations in the scalp hair of methamphetamine abusers.

The concentrations of 16 elements (As, Au, Ca, Cd, Co, Cr, Cu, Fe, Hg, Mg, Mn, Mo, Ni, Se, Sr and Zn) in the hair of 40 methamphetamine (METH) abusers and control subjects were determined by inductively coupled plasma mass spectrometry (ICP-MS). Comparisons of the element levels in the hair of properly matched METH abuser and control groups revealed significant imbalances in the concentrations of 6 elements (As, Au, Ca, Cu, Mg and Sr) between the abuser and control groups. Ca (p<0.01), Cu (p<0.05), Mg (p<0.01) and Sr (p<0.01) levels are significantly lower in the hair samples of METH abusers compared to control subjects, whereas the As (p<0.01) and Au (p<0.01) concentrations are higher. The concentration of the remaining elements in the hair of METH abusers was similar to the concentration in the control subjects. The geometric means for each element in hair of METH abuser and control subjects are presented. The cause of these alterations is also discussed.

Determination of 33 elements in scalp hair samples from inhabitants of a mountain village of Tonglu city, China.

Hair samples from 190 relatively healthy 20- to 98-year-old volunteers from a mountain village of Tonglu city (Zhejiang province, China) were analyzed to determine the contents of 33 chemical elements (Ag, Al, As, Au, B, Ba, Be, Ca, Cd, Co, Cr, Cs, Cu, Fe, Ga, Hg, Li, Mg, Mn, Mo, Ni, Pb, Rb, Sb, Se, Sr, Th, Ti, Tl, U, V, Zn, and Zr) with the aim of assessing preliminary reference values. Mean values, median values, ranges and selected percentiles of all element concentrations in scalp hair are presented. By comparing data from different countries, it was determined that the mean concentrations of the majority of elements in our study clearly differed from the mean levels reported in the literature. The effects of gender and age on element concentrations were also investigated. Significant differences that were correlated with age and gender were determined for certain elements. For example, Fe exhibited a mean value of 11.26mg/kg for males and 4.37mg/kg for females. An age-dependent pattern for Fe was also apparent when the two age subgroups of 20-59 and 60-98 years were compared.

Comparative normal/failing rat myocardium cell membrane chromatographic analysis system for screening specific components that counteract doxorubicin-induced heart failure from Acontium carmichaeli.

Cell membrane chromatography (CMC) derived from pathological tissues is ideal for screening specific components acting on specific diseases from complex medicines owing to the maximum simulation of in vivo drug-receptor interactions. However, there are no pathological tissue-derived CMC models that have ever been developed, as well as no visualized affinity comparison of potential active components between normal and pathological CMC columns. In this study, a novel comparative normal/failing rat myocardium CMC analysis system based on online column selection and comprehensive two-dimensional (2D) chromatography/monolithic column/time-of-flight mass spectrometry was developed for parallel comparison of the chromatographic behaviors on both normal and pathological CMC columns, as well as rapid screening of the specific therapeutic agents that counteract doxorubicin (DOX)-induced heart failure from Acontium carmichaeli (Fuzi). In total, 16 potential active alkaloid components with similar structures in Fuzi were retained on both normal and failing myocardium CMC models. Most of them had obvious decreases of affinities on failing myocardium CMC compared with normal CMC model except for four components, talatizamine (TALA), 14-acetyl-TALA, hetisine, and 14-benzoylneoline. One compound TALA with the highest affinity was isolated for further in vitro pharmacodynamic validation and target identification to validate the screen results. Voltage-dependent K(+) channel was confirmed as a binding target of TALA and 14-acetyl-TALA with high affinities. The online high throughput comparative CMC analysis method is suitable for screening specific active components from herbal medicines by increasing the specificity of screened results and can also be applied to other biological chromatography models.

Acute poisoning types and prevalence in Shanghai, China, from January 2010 to August 2011.

In recent years, the number of cases of acute poisoning has increased in China, yet; currently, there is no detailed report published that addresses acute poisoning in the mainland of China. We collected biological samples from 466 cases of suspected acute poisoning at the hospitals in Shanghai, China, and examined them using spectroscopy, chromatography and chromatography/mass spectrometry. Of the 466 cases, 230 cases (100 men and 130 women) were positively confirmed as acute poisonings. There were 80 types of compounds identified in this study. Medications were the most frequent substances identified, and the other substances included pesticides, multiple compounds, volatile compounds, natural toxins, and others. The results of this study indicate a need for strengthening the education about and management of the rational and safe use of drugs in Shanghai.

Method development and validation for determining 1,3-butadiene in human blood by gas chromatography-mass spectrometry and head-space gas chromatography.

To develop a simple, validated method for identifying and quantifying 1,3-butadiene (BD) in human blood by gas chromatography-mass spectrometry (GC-MS) and head-space gas chromatography (HS-GC). BD was identified by GC-MS and HS-GC, and quantified by HS-GC. The method showed that BD had a good linearity from 50 to 500 microg/mL (r > 0.99). The limits of detection and quantification were 10 microg/mL and 50 microg/mL, respectively. Both the intra-day precision and inter-day precision were < 6.08%, and the accuracy was 96.98%-103.81%. The method was applied to an actual case, and the concentration of BD in the case was 242 microg/mL in human blood. This simple method is found to be useful for the routine forensic analysis of acute exposure to BD.

Rapid screening of drugs of abuse in human urine by high-performance liquid chromatography coupled with high resolution and high mass accuracy hybrid linear ion trap-Orbitrap mass spectrometry.

A novel analytical toxicology method has been developed for the analysis of drugs of abuse in human urine by using a high resolution and high mass accuracy hybrid linear ion trap-Orbitrap mass spectrometer (LTQ-Orbitrap-MS). This method allows for the detection of different drugs of abuse, including amphetamines, cocaine, opiate alkaloids, cannabinoids, hallucinogens and their metabolites. After solid-phase extraction with Oasis HLB cartridges, spiked urine samples were analysed by HPLC/LTQ-Orbitrap-MS using an electrospray interface in positive ionisation mode, with resolving power of 30,000 full width at half maximum (FWHM). Gradient elution off of a Hypersil Gold PFP column (50mm×2.1mm) allowed to resolve 65 target compounds and 3 internal standards in a total chromatographic run time of 20min. Validation of this method consisted of confirmation of identity, selectivity, linearity, limit of detection (LOD), lowest limits of quantification (LLOQ), accuracy, precision, extraction recovery and matrix effect. The regression coefficients (r(2)) for the calibration curves (LLOQ - 100ng/mL) in the study were ≥0.99. The LODs for 65 validated compounds were better than 5ng/ml except for 4 compounds. The relative standard deviation (RSD), which was used to estimate repeatability at three concentrations, was always less than 15%. The recovery of extraction and matrix effects were above 50 and 70%, respectively. Mass accuracy was always better than 2ppm, corresponding to a maximum mass error of 0.8 millimass units (mmu). The accurate masses of characteristic fragments were obtained by collisional experiments for a more reliable identification of the analytes. Automated data analysis and reporting were performed using ToxID software with an exact mass database. This procedure was then successfully applied to analyse drugs of abuse in a real urine sample from subject who was assumed to be drug addict.

Distinguishing heroin abuse from codeine administration in the urine of Chinese people by UPLC-MS-MS.

Heroin is a highly addictive drug, and heroin abuse is considered to be a serious criminal act. The major metabolite of heroin, morphine, can usually be detected as evidence of heroin abuse. However, it is difficult to determine heroin use when morphine and codeine are both detected, because codeine use will also result in the presence of morphine in urine. Therefore, it is important to distinguish heroin abuse from codeine administration. In this study, urine samples from 21 volunteers with various ingestion patterns of a compound codeine phosphate oral solution were used as negative controls, and urine samples from 89 alleged heroin users were used as positive controls. Urine from single and multiple doses of codeine administration were collected at different time points for a systematic comparison. After protein precipitation, the urine samples were analyzed for the presence of free morphine, free codeine and their metabolites by ultra-performance liquid chromatography-tandem mass spectrometry. The method of percentiles, with median and standard interquartile ranges, was used to describe and analyze the data based on the normality of the distribution. The ratios of concentration of morphine and morphine to codeine were found to be the possible criteria to distinguish heroin users from codeine users in Chinese people.

[Determination of 33 inorganic elements in human hair by electricity plate digestion and inductively coupled plasma-mass spectrometry].

OBJECTIVE: To establish the electricity plate digestion and inductively coupled plasma-mass spectrometry (ICP-MS) method for determination of 33 inorganic elements in human hair. METHODS: Lithium (6Li), Germanium (72Ge), Yttrium (89Y), Indium (115In), and Terbium (159Tb) were used as internal standards. The electric heating board digestion in a mixture of nitric acid and hydrogen peroxide was used as the pre-treatment of the hair. Thirty-three inorganic elements in human hair were analyzed by ICP-MS method. RESULTS: The detection limit of ICP-MS was 0.0001 microg/g(Th)-10.9 microg/g (Ca) and the limit of quantitation was 0.0005 microg/g (Th)-25 microg/g (Ca). The recovery rate of this method was 86%-113%. The RSD for the intra-day and inter-day were less than 9.2%. The method was not statistically different from microwave digestion method. CONCLUSION: This method is highly efficient and accurate. It can be used for analysis of 33 inorganic elements in human hair.

[Simultaneous determination of penicillin G and its major metabolites in blood using ultra performance liquid chromatography-tandem mass spectrometry].

A fast method for the quantitative determination of penicillin G (PEN G) , penicilloic acid and penilloic acid in blood with ultra performance liquid chromatography-electrospray tandem mass spectrometry was developed. A simple deproteinization of the blood was used with a mixed solution of acetonitrile and water (4:1, v/v) as extraction solvent. The blood extract was directly injected onto an LC column. The chromatographic separation of the components was performed on a BEH C18 column (50 mm x 2.1 mm, 1.7 microm) using acetonitrile and water containing 0.1% formic acid. The mass spectrometer was operated in positive electrospray ion mode. Finally, the analysis was carried out with multiple reaction monitoring (MRM) mode. The limits of detection (LODs) for these three compounds were in the range of 0.1 to 2.0 ng/mL and the limits of quantification (LOQs) in the range of 0.5 to 5.0 ng/mL. Within the linear range, the correlation coefficients (r) of PEN G and its metabolites were all more than 0.9974. Accuracies for these targeted compounds were ranged from 92.3% to 105.5%, and the within-day precisions were less than 10%. The stabilities of the components were evaluated in the temperature range from 18 to 80 degrees C, and the mass concentration of penicillin G was decreased significantly with the extensions of storage temperature and storage time. Biological samples of the rats medicated with PEN G were analyzed using the developed method. The results show that PEN G can just be detected at 0.5 h after administration. However, the detection time limitation of penicilloic acid can be extended to 36 h. The established method has been further expanded for the applicability of forensic identification, and has a reference value for the detection of penicillin G residue in food.

[Screening and confirmation of psychotropic drugs in blood and urine by HPLC-LTQ Orbitrap MS].

OBJECTIVE: To establish a screening and confirmation method for psychotropic drugs and their metabolites in human blood and urine by HPLC-LTQ Orbitrap MS. METHODS: The samples were pretreated with Sirocco protein precipitation plate, and then analyzed by HPLC-LTQ Orbitrap MS. The method was validated in terms of the limit of detection (LOD). An accurate mass database was created for psychotropic drugs screening. RESULTS: The LOD for most of 56 determined compounds was < or = 0.1 ng/mL. The accurate mass database included the accurate mass information of 61 psychotropic drugs. CONCLUSION: The method is accurate, rapid, sensitive and the database is suitable for psychotropic drugs screening and confirmation.