Determination of aconitine in body fluids by LC-MS-MS

Plant Poisons in the Garden: A Human Risk Assessment

A study of the plants, and their associated poisons, in the Poison Garden at The Alnwick Garden was undertaken across a calendar year. By selecting 25 plants in the Poison Garden, we have been able to develop a single chromatographic method for the determination and quantification of 15 plant toxins by liquid chromatography mass spectrometry (LC-MS). Chromatographic separation was achieved on a C18 column (3.5 µm, 100 × 4.6 mm) with a gradient method using water +0.1% formic acid and methanol +0.1% formic acid. The developed method was validated for precision, linearity, limits of detection and quantification and extraction recoveries. The method showed good linearity with a R2 value of >0.995 for all 15 compounds with good precision of 10.7%, 6.7% and 0.3% for the low, medium and high calibration points, respectively. The LC-MS method was used to analyse 25 plant species, as well as their respective parts (i.e., bulb, flower, fruit, leaf, pollen, seed, stem and root), to assess the human risk assessment to children (aged 1 to <2 years) in relation to the plant toxin and its respective LD50. The analysis found that the greatest potential health risks were due to the ingestion of Colchicum autumnale and Atropa belladonna. As a caution, all identified plants should be handled with care with additional precautionary steps to ensure nil contact by children because of the potential likelihood of hand-to-mouth ingestion.

Progress in Immunoassays of Toxic Alkaloids in Plant-Derived Medicines: A Review

Plants are the cradle of the traditional medicine system, assuaging human or animal diseases, and promoting health for thousands of years. However, many plant-derived medicines contain toxic alkaloids of varying degrees of toxicity that pose a direct or indirect threat to human and animal health through accidental ingestion, misuse of plant materials, or through the food chain. Thus, rapid, easy, and sensitive methods are needed to effectively screen these toxic alkaloids to guarantee the safety of plant-derived medicines. Antibodies, due to their inherent specificity and high affinity, have been used as a variety of analytical tools and techniques. This review describes the antigen synthesis and antibody preparation of the common toxic alkaloids in plant-derived medicines and discusses the advances of antibody-based immunoassays in the screening and detection of toxic alkaloids in plants or other related matrices. Finally, the limitations and prospects of immunoassays for toxic alkaloids are discussed.

Optimization of the traditional processing method for precision detoxification of CaoWu through biomimetic linking kinetics and human toxicokinetics of aconitine as toxic target marker

ETHNOPHARMACOLOGICAL RELEVANCE

CaoWu (Aconiti Kusnezoffii Radix), well known for its high toxicity leading to fatal ventricular arrhythmias, is detoxified by HeZi (Terminalia Chebula Retz) decoction to prepare ZhiCaoWu (Aconiti Kusnezoffii Radix Preparata) as one part of ingredients of NaRu-3 pill which is used for the treatment of rheumatoid arthritis (RA). Aconitine (AC) is a highly toxic alkaloid of CaoWu and it is used as toxic target marker for the quality control (QC) of ZhiCaoWu. In the traditional processing method, the vanish of astringent or spicy feeling in tongue is the important detoxification indicator of ZhiCaoWu. However, how CaoWu is detoxified to ZhiCaoWu and whether the appropriate content of AC in ZhiCaoWu can be efficiently perceived after the empirical detoxification still lack factual basis.

AIM OF THE STUDY

The present study aimed to optimize the traditional processing method for precision detoxification of CaoWu through biomimetic linking kinetics and human toxicokinetics (TK) of AC, with a view of providing insights into the changes of toxic target marker.

MATERIALS AND METHODS

CaoWu medicinal slices (Mes) and coarse powder (Cop) were processed by blank HeZi decoction through the soaking method for 7 days. High-performance liquid chromatography (HPLC) was used for the analysis of the samples. The acidity of blank HeZi decoction and HeZi processing decoction was directly determined by pH meter. The non-compartment analysis (NCA) was used to have an intuitive appreciation for AC and pH changes in HeZi processing decoction while the compartment model method was used to build the biomimetic linking kinetics model with the covariate. The inter-species scaling of animal TK parameters was conducted to predict human AC TK profiles. The possible uptake ways of AC (rapid-release or extended-release) for humans were attempted to assess the poisoning risk of AC in NaRu-3 pill. Based on the target content of AC in ZhiCaoWu, the biomimetic linking kinetics model was explored to optimize the traditional processing detoxification method of CaoWu. The assays of determining inflammatory cytokines in lipopolysaccharides (LPS)-induced RAW264.7 cells were performed to investigate the inflammatory modulation effects of AC in vitro.

RESULTS

ZhiCaoWu was prepared by eliminating redundant AC in CaoWu through the repeatable replacement of HeZi processing decoction in which its acidity (pH) was affected. AC-pH changes in HeZi processing decoction were adequately depicted by a biomimetic linking kinetics model whose predictive power was determined by comparing the predictions of AC in ZhiCaoWu with the reported data. Rapid-release AC at the converted dose of 111.1 and 417.6 μg (0.011 and 0.042% of AC in NaRu-3 pill) reached maximum blood concentrations of 26.1 and 98.1 ng/mL at 0.3 h, in comparison with minimum human lethal concentration (100 ng/mL). Achieving the target content of AC (0.04%) in ZhiCaoWu or AC (0.011%) in NaRu-3 pill to precisely control the poisoning risk, the potential optimized protocols were that the processing time at 0.2-0.8% of AC in CaoWu was 2.0-4.4 days for Cop and 2.7-6.2 days for Mes. Correspondingly, pH values in HeZi processing decoction were 3.95 and 3.77 for Cop and Mes, respectively. Meanwhile, Lipopolysaccharides (LPS)-induced RAW264.7 cells were exposed to 0, 20, and 200 μM of AC for 12 h and AC at 20 μM enhanced the levels of IL-6, IL-10 and TNF-α.

CONCLUSIONS

Thus, for the first time, a biomimetic linking kinetics model was built to optimize the traditional detoxification method. Moreover, pH changes could be developed as surrogate endpoint for guiding the processing detoxification of CaoWu. Notably, setting the content limit of AC (0.011%) was very rational to control the poisoning risk of NaRu-3 pill. In addition, it was possible that there existed the more complex mechanisms of AC for inflammatory modulation in vitro.

Simultaneous quantification of nine aconitum alkaloids in Aconiti Lateralis Radix Praeparata and related products using UHPLC-QQQ-MS/MS

Aconiti Lateralis Radix Praeparata (Fuzi) is obtained from processed daughter roots of Aconitum carmichaeli, a toxic plant with a high medical value well known in Chinese medicine. In addition to the known toxic alkaloids (aconitine, mesaconitine, and hypaconitine) and bioactive alkaloids (benzoylaconine, benzoylmesaconine, and benzoylhypaconine), three rarely found alkaloids have been previously reported in Fuzi, i.e., yunaconitine, 8-deacetyl-yunaconitine, and crassicauline A, and they were reported in recent years to cause potential risk to patients who took Fuzi or related products. To better control the quality of this herb and its related products and ensure safe use, developing a method to simultaneously determine these 9 alkaloids is important. In this research, sensitive and accurate ultra-high-performance liquid chromatography coupled with triple quadrupole mass spectrometry method was established and used to examine 51 Fuzi and 27 Fuzi-containing products. Unexpectedly, 8-deacetyl-yunaconitine was detected in 17 Fuzi samples (33.3%) and 3 Fuzi-containing products (11.1%); yunaconitine in 10 Fuzi samples (19.6%) and 10 Fuzi-containing products (37.0%); and crassicauline A in 3 Fuzi samples (5.8%). Industry and clinics should be aware of the unusually high detection rate of these three toxic alkaloids in the Fuzi herb and its related products and take the necessary precautions to protect patients from any potential risk.

Quantification of aconitine in post-mortem specimens by validated liquid chromatography-tandem mass spectrometry method: three case reports on fatal 'monkshood' poisoning

The diester-diterpene alkaloid aconitine was quantified by liquid chromatography-tandem mass spectrometry in post-mortem specimens of three cases where suicidal ingestion of Aconitum napellus L. ('monkshood') was supposed. In an attempt at rationalization, sample preparation and chromatographic conditions of plasma/serum drug analysis routine were utilized. Linearity was established from 0.5 to 20 µg L⁻¹ using newborn calf serum (NCS) as a surrogate calibration matrix for all sample types and mesaconitine as an internal standard. Validation (selectivity, sensitivity, precision, accuracy, recovery of the extraction procedure, matrix effect, processed sample stability) confirmed the applicability of the analytical method to various post-mortem matrices. Internal standard selection was based on multi-matrix process efficiency data. In human post-mortem peripheral blood a lower limit of quantification of 0.51 µg L⁻¹ and a limit of detection of 0.13 µg L⁻¹ were accomplished (0.1 ml sample aliquots). Aconitine was degraded to a large extent in different sample types when being stored at +20 °C for 30 days, while at -20 °C and for some matrices also at +4 °C no appreciable degradation occurred. Aconitine concentrations in real samples were 10.3-17.9 µg L⁻¹ (peripheral blood, n = 3), 14.9-87.9 µg L⁻¹ (heart blood, n = 3), 317-481 µg L⁻¹ (urine, n = 2), 609-4040 µg L⁻¹ (stomach content, n = 3), 139-240 µg L⁻¹ (bile, n = 2), 8.4 µg L⁻¹ (vitreous humor, n = 1), 54.7 µg L⁻¹ (pericardial fluid, n = 1), 492 µg kg⁻¹ (liver, n = 1), 15.2-19.7 mg L⁻¹ (unknown liquids secured onsite, n = 3). Together with concomitant circumstances the analytical data provided compelling evidence for acute Aconitum poisoning as being the cause of death.

Cladosporium cladosporioides XJ-AC03, an aconitine-producing endophytic fungus isolated from Aconitum leucostomum

The endophytic fungus XJ-AC03, which was isolated from the healthy roots of Aconitum leucostomum, produced aconitine when grown in potato dextrose agar (PDA) medium. The presence of aconitine was confirmed by the chromatographic and spectroscopic analyses. The yield of aconitine was recorded as 236.4 μg/g by high performance liquid chromatography (HPLC). The mass spectrometry was shown to be identical to authentic aconitine. Further analysis with nuclear magnetic resonance (NMR) spectroscopy to show the chemical structure of the fungal aconitine indicated that the fungal aconitine produced an NMR spectrum identical to that of authentic aconitine. Strain XJ-AC03 was identified as Cladosporium cladosporioides by its characteristic culture morphology and ITS rDNA sequence analysis.

Fatal aconitine intoxication or thyroid storm? A case report

The case of a female in the latter half of her teens found dead in her father's apartment is reported. A glass containing liquid and plant remnants was found at the death scene. There were no indications of any intervention or the application of force by a third party. Autopsy showed unremarkable findings. Toxicological investigations revealed lethal doses of aconitine, a highly poisonous alkaloid and the major active compound of Aconitum napellus, in all specimens. Plant remnants were identified as A. napellus leaves by a botanist and toxicological examination of the liquid in the glass on site showed extremely high concentrations of aconitine. Additionally, laboratory results revealed that the young female was suffering from thyrotoxicosis factitia, an uncommon form of hyperthyroidism caused by misuse or overdosing of thyroid hormones in order to loose weight. A rare but serious and often fatal complication of hyperthyroidism is thyroid storm. Eventually the condition of thyroid storm due to thyrotoxicosis factitia could have contributed to the woman's death from aconitine poisoning.

Screening and analysis of aconitum alkaloids and their metabolites in rat urine after oral administration of aconite roots extract using LC-TOFMS-based metabolomics

Aconite roots are popularly used in herbal medicines in China. Many cases of accidental and intentional intoxication with this plant have been reported; some of these are fatal because the toxicity of aconitum is very high. It is thus important to detect and identify aconitum alkaloids in biofluids. In this work, an improved method employing LC-TOFMS with multivariate data analysis was developed for screening and analysis of major aconitum alkaloids and their metabolites in rat urine following oral administration of aconite roots extract. Thirty-four signals highlighted by multivariate statistical analyses including 24 parent components and 10 metabolites were screened out and further identified by adjustment of the fragmentor voltage to produce structure-relevant fragment ions. It is helpful for studying aconite roots in toxicology, pharmacology and forensic medicine. This work also confirmed that the metabolomic approach provides effective tools for screening multiple absorbed and metabolic components of Chinese herbal medicines in vivo.

Genus identification of toxic plant by real-time PCR

Some plants have toxicities that are dangerous for humans. In the case of poisoning by toxic plants, a rapid and easy screening test is required for accurate medical treatment or forensic investigation. In this study, we designed specific primer pairs for identification of toxic plants, such as subgenus Aconitum, genus Ricinus, genus Illicium, and genus Scopolia, by internal transcribed spacer sequences of nuclear ribosomal DNA. Allied species of target plants, foods, and human DNA were not detected, but each primer pair provided a specific PCR product from the target plant using real-time PCR. This method can detect the subgenus Aconitum, genus Ricinus, and genus Scopolia with template DNA of 10 pg, respectively, and genus Illicium with 1 pg. Furthermore, each primer pair provided the exact PCR product from digested target plants in artificial gastric fluid. When a trace unknown plant sample in forensic investigation is collected from stomach contents, this PCR assay may be useful for screening toxic plants.

Diterpenoid alkaloids

The lasting attention that researchers have devoted to diterpenoid alkaloids is due to their various bioactivities and toxicities, structural complexity, and intriguing chemistry. From 1998 to the end of 2008, more than 300 new diterpenoid alkaloids were isolated from Nature. This review focuses on their structural relationships, and investigations into their chemical reactions, synthesis, and biological activities. A table that lists the names, plant sources, and structural types is given along with 363 references.

[Simultaneous determination of aconitine analogues in Aconitum plants and foods that caused food poisoning by liquid chromatography with tandem mass spectrometry]

A simple method for the simultaneous determination of four aconitine analogues (AC; aconitine, HA; hypaconitine, MA; mesaconitine, JA; jesaconitine) in Aconitum plants (Aconitum subcuneatum NAKAI) and a food that caused food poisoning was developed, using liquid chromatography tandem mass spectrometry (LC/MS/MS). Aconitine analogues were extracted with 1 mmol/L HCl and then cleaned up with an Oasis HLB cartridge. The LC separation was performed with an octadecylated silica column (Develosil ODS-HG-5, 2.0 mm i.d. x 50 mm) at a flow rate of 0.2 mL/min, using A solution (5 mmol/L ammonium acetate dissolved in 0.1% acetic acid) and B solution (acetonitrile-THF=1 : 3), 90%A (0 min)-->60%A (15 min)-->const. (2 min). Mass spectral acquisition was performed in the positive mode and the analogues were targeted using multiple reaction monitoring (MRM) with electrospray ionization (ESI). The recoveries of aconitine analogues were 93-99% from Aconitum plants. The detection limits of AC, HA, MA and JA were 0.4, 0.4, 0.3 and 0.5 ng/g, respectively. The aconitine analogues, except JA, were detected in food that caused food poisoning at the level of 2.6-29.7 microg/g. These results indicate that the developed method is suitable for the determination of aconitine analogues in Aconitum plants and foods that cause food poisoning.

Simultaneous determination of three aconitum alkaloids in urine by LC-MS-MS

A sensitive method has been developed for the identification and quantification of the toxic alkaloids yunaconitine, crassicauline A, and foresaconitine in urine specimens. After solid-phase extraction using Oasis MCX cartridges, the extracts were analyzed by LC-MS-MS. The limit of detection is 0.03 ng/mL urine for yunaconitine and 0.05 ng/mL urine for crassicauline A and foresaconitine; the limit of quantitation is 0.15 ng/mL urine for yunaconitine and 0.20 ng/mL urine for crassicauline A and foresaconitine. The method was employed in the analysis of the urine of a 55-year-old male who died after ingestion of herbal medicine powder made from the roots of aconite. Yunaconitine, crassicauline A and foresaconitine were identified in the urine. Crassicauline A and foresaconitine were thus identified in a biological specimen for the first time.

Detection and validated quantification of toxic alkaloids in human blood plasma--comparison of LC-APCI-MS with LC-ESI-MS/MS

Poisonings with toxic plants may occur after abuse, intentional or accidental ingestion of plants. For diagnosis of such poisonings, multianalyte procedures were developed for detection and validated quantification of the toxic alkaloids aconitine, atropine, colchicine, coniine, cytisine, nicotine and its metabolite cotinine, physostigmine, and scopolamine in plasma using LC-APCI-MS and LC-ESI-MS/MS. After mixed-mode solid-phase extraction of 1 ml of plasma, the analytes were separated using a C8 base select separation column and gradient elution (acetonitrile/ammonium formate, pH 3.5). Calibration curves were used for quantification with cotinine-d(3), benzoylecgonine-d(3), and trimipramine-d(3) as internal standards. The method was validated according to international guidelines. Both assays were selective for the tested compounds. No instability was observed after repeated freezing and thawing or in processed samples. The assays were linear for coniine, cytisine, nicotine and its metabolite cotinine, from 50 to 1000 ng/ml using LC-APCI-MS and 1 to 1000 ng/ml using LC-ESI-MS/MS, respectively, and for aconitine, atropine, colchicine, physostigmine, and scopolamine from 5 to 100 ng/ml for LC-APCI-MS and 0.1 to 100 ng/ml for LC-ESI-MS/MS, respectively. Accuracy ranged from -38.6 to 14.0%, repeatability from 2.5 to 13.5%, and intermediate precision from 4.8 to 13.5% using LC-APCI-MS and from -38.3 to 8.3% for accuracy, from 3.5 to 13.8%, for repeatability, and from 4.3 to 14.7% for intermediate precision using LC-ESI-MS/MS. The lower limit of quantification was fixed at the lowest calibrator in the linearity experiments. With the exception of the greater sensitivity and higher identification power, LC-ESI-MS/MS had no major advantages over LC-APCI-MS. Both presented assays were applicable for sensitive detection of all studied analytes and for accurate and precise quantification, with the exception of the rather volatile nicotine. The applicability of the assays was demonstrated by analysis of plasma samples from suspected poisoning cases.

Characterization of metabolites and cytochrome P450 isoforms involved in the microsomal metabolism of aconitine

Aconitine, a major Aconitum alkaloid, is well known for its high toxicity that induces severe arrhythmias leading to death. The current study investigated the metabolism of aconitine and the effects of selective cytochrome P450 (CYP) inhibitors on the metabolism of aconitine in rat liver microsomes. The metabolites were separated and assayed by liquid chromatography-ion trap mass spectrometry (LC/MS(n)) and further identified by comparison of their mass spectra and chromatographic behaviors with reference substances. Various selective inhibitors of CYP were used to identify the isoforms of CYP, that involved in the metabolism of aconitine. A total of at least six metabolites were found and characterized in rat liver microsomal incubations. Result showed that the inhibitor of CYP 3A had an inhibitory effect on aconitine metabolism in a concentration-dependant manner, the inhibitor of CYP1A1/2 had a modest inhibitory effect, whereas inhibitors of CYP2B1/2, 2D and 2E1 had no obvious inhibitory effects on aconitine metabolism. Aconitine might be metabolized by CYP 3A and CYP1A1/2 isoforms in rat liver microsome.

Aconitine involvement in an unusual homicide case

We describe a homicide complicated by an aconitine poisoning, which was initially thought to be a strangulation case. Routine toxicological analyses demonstrated only a small amount of alcohol in the blood and the urine. The case could not be clarified until 5 years after the event. A new element in the investigation made the wife the prime suspect, and finally, after thorough interrogation, she confessed her crime. She had mixed a decoction of three plants of Aconitum with red wine. Additional toxicological analyses, using the liquid chromatography-tandem mass spectrometry (LC-MS-MS) technique demonstrated 810 ng/ml of aconitine in urine, 6.5 ng/g in liver and 1.3 ng/g in the kidneys. Even though aconitine poisoning is still rare in Europe, it should be taken into account in suicides and homicides, particularly in unclarified cases.

HPLC-UV method for nicotine, strychnine, and aconitine in dairy products

The toxic nitrogen alkaloids nicotine, strychnine, and aconitine were quantitated in whole milk, skim milk, and cream using solid-phase extraction cleanup and HPLC-UV with dual wavelength detection. Samples were extracted in McIlvaine's buffer with EDTA and then partitioned with aqueous acetonitrile and hexane. The aqueous phase was concentrated and passed through an OASIS HLB column. The column was eluted with methylene chloride/ammonium hydroxide, 1 mL/1 microL, v/v. The eluent was acidified with hydrochloric acid and evaporated. The sample was diluted for HPLC with acetonitrile/phosphate buffer pH 7.4. Chromatography was performed on an Xterra RP-18 column using a gradient of acetonitrile and ammonium bicarbonate buffer at pH 9.8. Nicotine and strychnine were monitored at 260 nm; aconitine was monitored at 232 nm. Calibration curves were generated from external standards in the range 0.2-10 microg/mL using 1/x weighting. Mean recoveries in whole milk spiked between 0.1 and 10 ppm were the following: nicotine 89.2%, strychnine 75.7%, and aconitine 85.1%. Mean recoveries in skim milk spiked between 0.1 and 10 ppm were the following: nicotine 72.1%, strychnine 78.2%, and aconitine 82.9%. Mean recoveries in cream spiked between 0.2 and 20 ppm were the following: nicotine 87.9%, strychnine 76.9%, and aconitine 82.0%. Relative standard deviations of recovery were less than 20% in each case.

Sensitive analysis of aconitine, hypaconitine, mesaconitine and jesaconitine in human body fluids and Aconitum tubers by LC/ESI-TOF-MS

The Aconitum species (Ranunculaceae) are widely distributed in northern Asia and North America. Their roots are popularly used in herbal medicines in China and Japan. Many cases of accidental, suicidal and homicidal intoxication with this plant have been reported; some of these were fatal because the toxicity of Aconitum is very high. It is thus important to detect and quantify Aconitum alkaloids in body fluids, with high sensitivity. We have developed a simple and sensitive method for measuring four kinds of Aconitum alkaloids (aconitine, hypaconitine, jesaconitine and mesaconitine) by LC/electrospray (ESI)-time-of-flight (TOF)-MS. For all of them, only molecular ions were observed at an orifice voltage of 75 V; at 135 V, base peaks corresponding to [M - 60 + H]+ ions were observed. These four compounds and methyllycaconitine (internal standard) in human plasma samples were purified by solid-phase extraction. The four extracted compounds were completely separated in mass chromatograms; the calibration curves showed good linearity in the range 10-300 ng/ml, and the detection limits were estimated to be 0.2-0.5 ng/ml. Using our method, we also determined the amounts of these compounds in tuber samples. The present method is applicable in clinical and forensic toxicology.

LC-ESI-MS/MS on an ion trap for the determination of LSD, iso-LSD, nor-LSD and 2-oxo-3-hydroxy-LSD in blood, urine and vitreous humor

A method has been developed for the simultaneous determination of lysergic acid diethylamide (LSD), its epimer iso-LSD, and its main metabolites nor-LSD and 2-oxo-3-hydroxy LSD in blood, urine, and, for the first time, vitreous humor samples. The method is based on liquid/liquid extraction and liquid chromatography-multiple mass spectrometry detection in an ion trap mass spectrometer, in positive ion electrospray ionization conditions. Five microliter of sample are injected and analysis time is 12 min. The method is specific, selective and sensitive, and achieves limits of quantification of 20 pg/ml for both LSD and nor-LSD in blood, urine, and vitreous humor. No significant interfering substance or ion suppression was identified for LSD, iso-LSD, and nor-LSD. The interassay reproducibilities for LSD at 20 pg/ml and 2 ng/ml in urine were 8.3 and 5.6%, respectively. Within-run precision using control samples at 20 pg/ml and 2 ng/ml was 6.9 and 3.9%. Mean recoveries of two concentrations spiked into drug free samples were in the range 60-107% in blood, 50-105% in urine, and 65-105% in vitreous humor. The method was successfully applied to the forensic determination of postmortem LSD levels in the biological fluids of a multi drug abuser; for the first time, LSD could be detected in vitreous humor.

Quantitative determination of taxine B in body fluids by LC–MS–MS

A new specific and sensitive LC-MS-MS method for the detection of taxine B and isotaxine B, the main toxic pseudo-alkaloids from yew (Taxus sp.), in biological samples (blood, urine, gastric content) was developed. Biological samples were prepared for LC-MS-MS by means of solid-phase extraction (SPE) procedure and yielded a recovery of 86%. Chromatographic separation was achieved using an RP(18) column. Detection of taxine B and isotaxine B was performed using multiple reaction monitoring with m/z 584.2 as precursor ion, i.e. [M+H](+), of both isomers and m/z 194.3 and m/z 107.1 as product ions after collision-induced dissociation. Docetaxel was applied as internal standard. The method was fully validated for the analysis of blood samples. Linearity was proven in the range from 0.1-500 ng/g. The limit of detection and the limit of quantitation are 0.4 and 2 ng/g, respectively. The method was applied to the determination of taxine B and isotaxine B in four fatal cases (two humans, two horses) with suspected yew intoxication. Blood levels were 105, 168, 174 and 212 ng/g.

Quantification of benzodiazepines in whole blood and serum

A high-performance liquid chromatography method for the determination of benzodiazepines and their metabolites in whole blood and serum using mass spectrometry (MS) and photodiode array (PDA) detection is presented. The combination of both detection types can complement each other and provides extensive case relevant data. The limits of quantification (LOQ) with the MS detection lie between 2 and 3 microg/l for the following benzodiazepines or metabolites: 7-amino-flunitrazepam, alprazolam, desalkyl-flurazepam, desmethyl-flunitrazepam, diazepam, flunitrazepam, flurazepam, alpha-hydroxy-midazolam, lorazepam, midazolam, nitrazepam, nordazepam and oxazepam, respectively 5 microg/l for lormetazepam and 6 microg/l for bromazepam. The LOQ of clobazam determined with the PDA detector is 10 microg/l. A convenient approach for determining the measurement uncertainty of the presented method--applicable also for other methods in an accreditation process--is presented. At low concentrations (<10 microg/l), measurement uncertainty was estimated to be about 50%, and at concentrations >180 microg/l, it was estimated to be about 15%. One hundred and twenty-eight case data acquired over 1 year are summarised.

A non-fatal oleander poisoning

The study presents a case of non-fatal poisoning with oleander blooms in a 47-year-old female, with emphasis on the importance of toxicological service in a clinical emergency. After repeated vomiting at home, the patient was admitted at the hospital with cardiac symptoms more than 18 h after the ingestion. Serum samples were assayed immunochemically for digitoxin-related compounds by electrochemiluminescent immunoassay, and using HPLC/MS/MS analysis for oleandrin, the main cardiac glycoside of Nerium oleander. Confirming the non-specific immunoassay results, which are often clinically over-interpreted, oleandrin was detected by HPLC/MS/MS in the serum sample in a concentration of 1.6 ng/ml upon admission. Comparison with previous reports indicates that single compound analysis only permits a toxicological assessment for oleander poisoning and results in the proposal to classify an oleandrin level between 1.0 and 2.0 ng/ml as toxic blood plasma/serum concentration.