Determination of salmeterol, α-hydroxysalmeterol and fluticasone propionate in human urine and plasma for doping control using UHPLC-QTOF-MS.

Salmeterol and fluticasone are included in the Prohibited List annually issued by the World Anti-Doping Agency. While for other permitted beta-2 agonists a threshold has been established, above which any finding constitutes an Adverse Analytical Finding, this is not the case with salmeterol. The salmeterol metabolite, α-hydroxysalmeterol, has been described as a potentially more suitable biomarker for the misuse of inhaled salmeterol. In this study, a new and rapid UHPLC-QTOF-MS method was developed and validated for the simultaneous quantification of salmeterol, α-hydroxysalmeterol and fluticasone in human urine and plasma, which can be used for doping control. The analytes of interest were extracted by means of solid phase extraction and were separated on a Zorbax Eclipse Plus C18 column. Detection was performed in a quadrupole time-of-flight mass spectrometer equipped with an electrospray ionization source, in positive mode for the detection of salmeterol and its metabolite and in negative mode for the detection of fluticasone. Method was validated over a linear range from 0.10 to 2.00 ng/ml for salmeterol and fluticasone, and from 1.00 to 20.0 ng/ml for α-hydroxysalmeterol, in urine, whereas in plasma, the linear range was from 0.025 to 0.500 ng/ml for salmeterol and fluticasone, respectively.

Official International Association for Therapeutic Drug Monitoring and Clinical Toxicology Guideline: Development and Validation of Dried Blood Spot-Based Methods for Therapeutic Drug Monitoring.

Dried blood spot (DBS) analysis has been introduced more and more into clinical practice to facilitate Therapeutic Drug Monitoring (TDM). To assure the quality of bioanalytical methods, the design, development and validation needs to fit the intended use. Current validation requirements, described in guidelines for traditional matrices (blood, plasma, serum), do not cover all necessary aspects of method development, analytical- and clinical validation of DBS assays for TDM. Therefore, this guideline provides parameters required for the validation of quantitative determination of small molecule drugs in DBS using chromatographic methods, and to provide advice on how these can be assessed. In addition, guidance is given on the application of validated methods in a routine context. First, considerations for the method development stage are described covering sample collection procedure, type of filter paper and punch size, sample volume, drying and storage, internal standard incorporation, type of blood used, sample preparation and prevalidation. Second, common parameters regarding analytical validation are described in context of DBS analysis with the addition of DBS-specific parameters, such as volume-, volcano- and hematocrit effects. Third, clinical validation studies are described, including number of clinical samples and patients, comparison of DBS with venous blood, statistical methods and interpretation, spot quality, sampling procedure, duplicates, outliers, automated analysis methods and quality control programs. Lastly, cross-validation is discussed, covering changes made to existing sampling- and analysis methods. This guideline of the International Association of Therapeutic Drug Monitoring and Clinical Toxicology on the development, validation and evaluation of DBS-based methods for the purpose of TDM aims to contribute to high-quality micro sampling methods used in clinical practice.

Hydrophilic Interaction Liquid Chromatography-Electrospray Ionization Mass Spectrometry for Therapeutic Drug Monitoring of Metformin and Rosuvastatin in Human Plasma.

In this work a hydrophilic interaction liquid chromatography/positive ion electrospray mass spectrometric assay (HILIC/ESI-MS) has been developed and fully validated for the quantitation of metformin and rosuvastatin in human plasma. Sample preparation involved the use of 100 µL of human plasma, following protein precipitation and filtration. Metformin, rosuvastatin and 4-[2-(propylamino) ethyl] indoline 2 one hydrochloride (internal standard) were separated by using an X-Bridge-HILIC BEH analytical column (150.0 × 2.1 mm i.d., particle size 3.5 µm) with isocratic elution. A mobile phase consisting of 12% (v/v) 15 mM ammonium formate water solution in acetonitrile was used for the separation and pumped at a flow rate of 0.25 mL min−1. The linear range of the assay was 100 to 5000 ng mL−1 and 2 to 100 ng mL−1 for metformin and rosuvastatin, respectively. The current HILIC-ESI/MS method allows for the accurate and precise quantitation of metformin and rosuvastatin in human plasma with a simple sample preparation and a short a chromatographic run time (less than 15 min). Plasma samples from eight patients were further analysed proving the capability of the proposed method to support a wide range of clinical studies.

Development and validation of a LC/MS method for the determination of Δ(9)-tetrahydrocannabinol and 11-carboxy-Δ(9)-tetrahydrocannabinol in the larvae of the blowfly Lucilia sericata: Forensic applications.

In a number of forensic toxicological cases, Δ(9)-tetrahydrocannabinol (THC) and its metabolite 11-carboxy-delta-9-tetrahydrocannabinol (THCA) are frequently considered as contributor factors to the event. To that, a liquid chromatographic mass spectrometric method is described for the identification and quantitation of THC and its metabolite THCA in the forensically important larvae of L. sericata. Larvae of Lucilia sericata were fortified with varying concentrations of THC and THCA covering the calibration range between 10 and 500pg/mg. For the isolation of the analytes from larvae, several extraction techniques were evaluated and finally liquid-liquid extraction under acidic pH was selected using hexane-ethyl acetate (50:50, v/v) as extraction solvent. For the chromatographic separation, a Waters Symmetry® C18 analytical column was used while the mobile phase was acetonitrile-ammonium acetate (2mM) (30:70, v/v). The detection was performed using electrospray ionization source in negative mode (ESI-) and the selected ions monitored were m/z 313 for THC and m/z 343 for THCA. The proposed method which is simple and sufficiently sensitive for the detection of THC and THCA even in a single larva sampling, assisted the investigation of a forensic case.

Highly sensitive determination of 68 psychoactive pharmaceuticals, illicit drugs, and related human metabolites in wastewater by liquid chromatography-tandem mass spectrometry.

The present work describes the development and validation of a highly sensitive analytical method for the simultaneous determination of 68 compounds, including illicit drugs (opiates, opioids, cocaine compounds, amphetamines, and hallucinogens), psychiatric drugs (benzodiazepines, barbiturates, anesthetics, antiepileptics, antipsychotics, antidepressants, and sympathomimetics), and selected human metabolites in influent and effluent wastewater (IWW and EWW) by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). The method involves a pre-concentration and cleanup step, carried out by solid-phase extraction (SPE) using the adsorbent Strata-XC, followed by the instrumental analysis performed by LC-MS/MS, using a Kinetex pentafluorophenyl (PFP) reversed-phase fused-core column and electrospray ionization (ESI) in both positive and negative modes. A systematic optimization of mobile phases was performed to cope with the wide range of physicochemical properties of the analytes. The PFP column was also compared with two reversed-phase columns: fused-core C18 and XB-C18 (with a cross-butyl C18 ligand). SPE optimization and critical aspects associated with the trace level determination of the target compounds (e.g., matrix effects) have been also considered and discussed. Fragmentation patterns for all the classes were proposed. The validated method provides absolute recoveries between 75 and 120% for most compounds in IWW and EWW. Low method limits of detection were achieved (between 0.04 and 10.0 ng/L for 87% of the compounds), allowing a reliable and accurate quantification of the analytes at trace level. The method was successfully applied to the analysis of these compounds in five wastewater treatment plants in Santorini, a touristic island of the Aegean Sea, Greece. Thirty-two out of 68 compounds were detected in all IWW samples in the range between 0.6 ng/L (for nordiazepam) and 6,822 ng/L (for carbamazepine) and 22 out of 68 in all EWW samples, with values between 0.4 ng/L (for 9-OH risperidone) and 2,200 ng/L (for carbamazepine). The novel methodology described herein maximizes the information on the environmental analysis of these substances and also provides a first profile of 68 drugs in a Greek touristic area.

Development and validation of a method for the determination of buprenorphine and norbuprenorphine in breast milk by gas chromatography-mass spectrometry.

Buprenorphine (BUP) is used for the maintenance of opioid-addicted pregnant women. Because BUP and its main metabolite nor-BUP are excreted into breast milk, a sensitive and specific GC/MS method has been developed, optimized and validated for their determination in breast milk. BUP-d4 was used as internal standard. The sample preparation includes combination of protein precipitation with solid-phase extraction and derivatization (acetylation). The absolute recovery for both analytes was found to be higher than 87.3%. The limits of detection and quantification were 0.07 and 0.20 µg/L, respectively. The calibration curves were linear within the dynamic range 0.20-20.0 µg/L, with a correlation coefficient higher than 0.996. Intra- and inter-day accuracies were ranged from -7.06 to 4.50 and from -5.88 to 7.00%, respectively, while intra- and inter-day precision were less than 5.7 and 6.1%. The analytes were found to be stable in breast milk at 4 °C for one week, at -20 °C for one month, and after three freeze-thaw cycles. The method can be used for the determination of BUP and nor-BUP in breast milk of BUP-maintained mothers, in order to calculate the amount of drug that could pass to the newborn via breast milk and to avoid toxic consequences of breastfeeding.

Naphyrone: a "legal high" not legal any more.

Naphyrone, also known as naphthylpyrovalerone and O-2482, is a cathinone derivative that has been recently advertized for purchase on a number of websites. Naphyrone belongs to a new class of "designer drugs" that has emerged on the drugs abuse market and has gained popularity as the new "legal high." Legal highs have been circulating for a number of years in Europe and are becoming popular in the United States. They are affordable, widely available, legal to use and possess, and legal to supply. This review presents any available information about safety profile, clinical data, analytical profile, and legislation of this legal high, which is not legal any more. Any available information has been collected by various literature search engines and the World Wide Web. The structure of naphyrone is similar to that of pyrovalerone, a monoamine uptake inhibitor. This new designer drug does not have a long history of use, so there is little evidence of its long-term effects or on the risks from its use. Because of its similarity to other cathinone derivatives, naphyrone is likely to share the same risks, such as anxiety, paranoia, and overstimulation of the heart and circulatory system. Naphyrone was classified as a controlled drug under the UK Misuse of Drugs Act of 1971 (Amendment No. 2) Regulation 2010.

Migration study of 1,3-butadiene in eye-drop solutions.

The potential deleterious effects of extractables/leachables in pharmaceutical products led the USP, EP, and JP to require extractable and toxicity testing of container/closure systems. To that, a headspace gas chromatography flame ionization detection method was developed and validated for the determination of 1,3-butadiene (1,3-BD) as a potential extractable residue from a pharmaceutical container/closure system into eye-drop solutions. A migration study was further applied in eight eye-drop solutions (currently marketed products) after short- and long-term exposure of these products at various temperatures. This method allows the establishment of safety-qualification thresholds for 1,3-BD being capable of monitoring eye-drop solution products for this residue.

Development and validation of a gas chromatography-mass spectrometric method for the determination of sildenafil and desmethyl-sildenafil in whole blood.

Sildenafil (SDL) is a phosphodiesterase type 5 inhibitor and it is approved for the treatment of erectile dysfunction and pulmonary hypertension. SDL is extensively metabolized to its pharmacologically active metabolite, desmethyl-sildenafil (DSDL). A sensitive and specific GC/MS method for the determination of SDL and DSDL in whole blood was developed and validated to support therapeutic drug monitoring of SDL patients. The combination of solid-phase extraction with derivatization using BSTFA with 1% TMCS in acetonitrile efficiently reduced matrix effect and improved sensitivity of the method. In this assay, protriptyline was used as internal standard for both analytes. The LODs were 1.50 and 5.00 ng/mL for SDL and DSDL, respectively, whereas the respective LOQs were 5.00 and 15.0 ng/mL. The calibration curves were linear up to 500.0 ng/mL (SDL: R(2) 0.992, DSDL: R(2) 0.990). Absolute recovery values for both analytes ranged from 83.1 to 93.2%. Within- and between-batch accuracy was less than 11.8 and 10.2%, respectively, whereas within- and between-batch precision was less than 8.1 and 10.8%, correspondingly. The developed method is suitable for the determination of SDL and DSDL concentrations in blood samples obtained from patients under Viagra(®) treatment, for pharmacokinetic studies or for the investigation of related forensic cases.

Development and validation of an EI-GC-MS method for the determination of methadone and its major metabolites (EDDP and EMDP) in human breast milk.

Methadone is used extensively for the maintenance of opioid-addicted pregnant women. Because methadone and the two major metabolites, 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP) and 2-ethyl-5-methyl-3,3-diphenylpyrroline (EMDP), are excreted into breast milk, a sensitive and specific gas chromatographic-mass spectrometric method has been developed, optimized, and validated for their quantitative determination in human breast milk. The procedure combined protein precipitation with acetonitrile and solid-phase extraction, using Isolute Confirm HCX mixed-mode SPE columns, with minimal matrix effect. The optimum extraction conditions for all three analytes were evaluated using spiked human breast milk, and the recovery exceeded 93.0%. This assay uses methadone-d(9) as internal standard for the determination of methadone and EMDP, and EDDP-d(3) for the determination of EDDP. Calibration curves were linear within the range of 2.00-1000 microg/L for methadone (R(2) > 0.995) and 1.00-500 microg/L for EDDP (R(2) >0.997) and EMDP (R(2) > 0.991). Intra- and interday accuracy and precision were within the range of 0.8-5.7% and 1.3-5.2%, respectively, for all analytes. The stability study was assessed by fortifying human breast milk with methadone and its metabolites at two different concentrations and keeping the samples at different temperature conditions. The analytes were found to be stable in breast milk at room temperature for at least 4 h and at -20 degrees C for at least one month. The method was used for the determination of methadone and its major metabolites in human breast milk samples obtained from women in the postpartum period participating in a methadone maintenance program.

The impact of nutrition education on nutrition knowledge and adherence to the Mediterranean Diet in adolescent competitive swimmers.

OBJECTIVES: Nutrition education of adolescent competitive swimmers is under-studied although their diet and nutrition knowledge are generally poor. This study aimed to assess the impact of nutrition education on nutrition knowledge and adherence to the Mediterranean Diet (MD) and explore the effect of parental education on the swimmers' MD adherence. DESIGN: A pre-post measurement interventional study was carried out. METHODS: A half-day nutrition education session was delivered for the swimmers and a separate session for their parents. At baseline and 6-weeks post-workshop, a short nutrition knowledge assessment of food sources of nutrients and the MD composition as well as adherence to the MD using the KIDMED Index were undertaken. The swimmers' parents also completed the KIDMED Index to evaluate the swimmers' diet. RESULTS: Thirty-four competitive swimmers (age: 15.2±1.5 yr, 23 males) and 22 of their parents participated in the study. There was an improvement in MD adherence with 47% having good adherence post-intervention vs 21% at baseline (p<0.01) and an increase in the KIDMED Index score (median [interquartile range]: 5.0 [4.0-7.0] vs 7.0 [7.0-9.0]; p<0.01)). There was also an increase in the swimmers' nutrition knowledge assessment score (median [IQR]: 7.0 [5.0-8.0] vs 7.0 [6.0-8.0], p<0.05)), and a trend for a lower score post-intervention in swimmers whose parents did not participate compared to those whose parents participated (6.0 [6.0-7.8] vs 7.0 [7.0-8.0], p=0.063). CONCLUSIONS: The intervention improved adherence to the MD and increased nutrition knowledge. The findings support parental participation in nutrition education.

Bioanalytical LC-MS Method for the Quantification of Plasma Androgens and Androgen Glucuronides in Breast Cancer.

The physiological and pathological development of the breast is strongly affected by the hormonal milieu consisting of steroid hormones. Mass spectrometry (MS) technologies of high sensitivity and specificity enable the quantification of androgens and consequently the characterization of the hormonal status. The aim of this study is the assessment of plasma androgens and androgen glucuronides, in the par excellence hormone-sensitive tissue of the breast, through the application of liquid chromatography-mass spectrometry (LC-MS). A simple and efficient fit-for-purpose method for the simultaneous identification and quantification of dehydroepiandrosterone sulfate (DHEAS), androstenedione (A4), androsterone glucuronide (ADTG) and androstane-3α, 17ß-diol-17-glucuronide (3α-diol-17G) in human plasma was developed and validated. The presented method permits omission of derivatization, requires a single solid-phase extraction procedure and the chromatographic separation can be achieved on a single C18 analytical column, for all four analytes. The validated method was successfully applied for the analysis of 191 human plasma samples from postmenopausal women with benign breast disease (BBD), lobular neoplasia (LN), ductal carcinoma in situ and invasive ductal carcinoma (IDC). DHEAS plasma levels exhibited significant differences between LN, IDC and BBD patients (P < 0.05). Additionally, ADTG levels were significantly higher in patients with LN compared with those with BBD (P < 0.05).

Multi-residue determination of 10 selected new psychoactive substances in wastewater samples by liquid chromatography-tandem mass spectrometry.

New psychoactive substances (NPSs) have become increasingly popular in recent years. The analysis of these substances in influent wastewater (IWW) can be used to track their use in communities. In addition, an evaluation of the amount of NPSs released to the aquatic environment can be performed through the analysis of effluent wastewater (EWW). This study presents the development, validation and application of an analytical methodology, based on solid phase extraction (SPE) and liquid chromatography-tandem mass spectrometry (LC-MS/MS), for the determination of 10 NPSs in IWW and EWW. Synthetic cannabinoids, cathinones, piperazines and pyrrolidophenones are included among the target analytes. To the authors' knowledge, it is the first time that eight out of these substances (4'-methylpyrrolidinobutyrophenone (MPPP), a-pyrrolidinopentiophenone (a-PVP), 2-[(1S,3R)-3-hydroxycyclohexyl]-5-(2-methyl-2-octanyl) phenol (CP47,497), (1-naphthyl(1-pentyl-1H-indol-3-yl) methanone (JWH-018), (1-butyl-1H-indol-3-yl)(1-naphthyl) methanone (JWH-073), (4-ethyl-1-naphthyl)(1-pentyl-1H-indol-3-yl) methanone (JWH-210), (4-methyl-1-naphthyl) (1-pentyl-1H-indol-3-yl) methanone (JWH-122) and 2-(2-methoxyphenyl)-1-(1-pentyl-1H-indol-3-yl) ethanone (JWH-250)) are investigated in wastewater. The optimized conditions for the analysis of this set of compounds included a SPE clean-up step using a polymeric sorbent and the use of a pentafluorophenyl (PFP) chromatographic column. Despite the broad range of physicochemical properties of the analytes the method allowed acceptable absolute recoveries (40-109%) for all the studied compounds at different levels of concentration. Low method limits of detection (MLODs) were achieved, ranging between 0.3 and 10 ng/L except for BZP and CP47,497 (20 and 23 ng/L, respectively), allowing a reliable and accurate quantification of the analytes. The method was successfully applied to the analysis of IWW and EWW samples from five wastewater treatment plants (WWTPs) located in Santorini Island (a highly touristic resort in Greece). Four out of 10 compounds (a-PVP, CP47,497, JWH-122 and JWH-210) were detected at least in one sample, being the first evidence of their presence in wastewater. CP47,497 was the most ubiquitous and abundant compound, showing concentrations up to 634 ng/L in some cases.

Liquid chromatography-positive ion electrospray mass spectrometry method for the quantification of citalopram in human plasma.

A rapid, sensitive and novel narrow-bore liquid chromatography-mass spectrometric method was developed and fully validated for the quantification of citalopram in human plasma. The analyte and internal standard (imipramine) were extracted by liquid-liquid extraction with a mixture of hexane-heptane-isopropanol (88:10:2, v/v/v). The use of a Hypersil BDS C(8) micro-bore column (250 mm x 2.1 mm i.d.; 3.5 microm particle size), results in substantial reduction in solvent consumption. The mobile phase consisted of 10 mM ammonium formate-formic acid (pH 4.5) and acetonitrile (30:70, v/v), pumped at a flow rate of 0.15 ml min(-1). The analytes were detected after positive electrospray ionization using the selected ion-monitoring mode of the species at m/z 325 for citalopram and m/z 281 for imipramine. The method had a chromatographic run time of 10.0 min and a linear calibration curve over the range 0.50-250 ng ml(-1) (r(2) > 0.996). The limit of quantitation was 0.50 ng ml(-1). Accuracy and precision were below the acceptance limits of 15%.

Stability of morphine, codeine, and 6-acetylmorphine in blood at different sampling and storage conditions.

The stability of drugs in biological specimens is a major concern during the evaluation of the toxicological results. The stability of morphine, codeine, and 6-acetyl-morphine in blood was studied after different sampling conditions: (i) in glass, polypropylene or polystyrene tubes, (ii) with addition of dipotassium ethylene diamine tetraacetic acid (K2EDTA) or sodium oxalate (Na2C2O4), and (iii) with or without the addition of sodium fluoride (NaF). Spiked blood samples were stored at two different temperatures (4 and -20°C), analyzed after different storage times and after three freeze­thaw cycles. Opiate concentrations were decreased in all conditions, but the most unstable was 6-acetyl-morphine. The addition of NaF as preservative improved the stability of opiates at all conditions studied, whereas the type of anticoagulant did not affect the stability of opiates. It was concluded that blood samples should be stored at -20°C in glass tubes containing oxalate and NaF for maximum stability.

A validated GC/MS method for the determination of amisulpride in whole blood.

A sensitive GC/MS method for the determination of amisulpride in whole blood was developed, optimized and validated. Sample preparation included solid-phase extraction using HF Bond Elut C18 cartridges and further derivatization with heptafluorobutyric anhydride (HFBA). The limits of detection and quantification were 3.00 and 10.0 µg/L, respectively. The calibration curves were linear up to 1000 µg/L (R(2)≥0.991). Absolute recovery ranged from 94.2 to 101%. Accuracy was found to be between -8.7 and 1.9% and imprecision was less than 10.0%. The developed method covers the generally accepted therapeutic range but it can also cover levels above them. This makes our method suitable for the determination of amisulpride not only for clinical purposes on psychiatric patients, but also during the investigation of forensic cases where amisulpride is involved.

The clavicle bone as an alternative matrix in forensic toxicological analysis.

Although human blood is the reference medium in the field of forensic toxicology, alternative matrices may be required when traditional specimens are not available, especially in the investigation of cases involving decomposing remains. Clavicle bone may provide an appropriate sample of choice since it can easily be obtained at autopsy after the removal of the breastplate for the inspection of the thoracic viscera. To the author's knowledge, this is the first time that clavicle bone is used as an alternative matrix for the detection of drugs. The present study aimed to investigate the suitability of clavicle bone as an alternative matrix for the detection of opiates. Opiates were assayed using a gas chromatography-mass spectrometry in the selected ion monitoring mode. Morphine-d6, codeine-d6 and 6-MAM-d3 were used as internal standards for the determination of morphine, codeine and 6-MAM, respectively. A GC/MS method was developed and validated for the determination of opiates in clavicle samples. Morphine, codeine and 6-MAM were successfully separated in spiked samples allowing for their detection at low levels without interferences from the matrix. Chromatographic run time was 11 min and the tested linearity ranged from 5 to 500 ng/g (r2 > 0.99) for all analytes. The method was further applied in clavicle samples of drug-related cases. Its validation parameters and the application of the developed method in clavicle samples from drug addicts, prove its suitability for the detection of opiates and potentially other drugs.

Hydrophilic interaction liquid chromatography/positive ion electrospray ionization mass spectrometry method for the quantification of alprazolam and α-hydroxy-alprazolam in human plasma.

A hydrophilic interaction liquid chromatography/positive ion electrospray-mass spectrometry (HILIC-ESI/MS) has been developed and fully validated for the quantification of alprazolam and its main metabolite, α-hydroxy-alprazolam, in human plasma. The assay is based on 50µL plasma samples, following liquid-liquid extraction. All analytes and the internal standard (tiamulin) were separated by hydrophilic interaction liquid chromatography using an X-Bridge-HILIC analytical column (150.0mm×2.1mm i.d., particle size 3.5µm) under isoscratic elution. The mobile phase was composed of a 7% 10mM ammonium formate water solution in acetonitrile and pumped at a flow rate of 0.20mLmin(-1). Running in positive electrospray ionization and selected ion monitoring (SIM) the mass spectrometer was set to analyze the protonated molecules [M+H](+) at m/z 309, 325 and 494 for alprazolam, α-hydroxy-alprazolam and tiamulin (ISTD) respectively. The assay was linear over the concentration range of 2.5-250ngmL(-1) for alprazolam and 2.5-50ngmL(-1) for α-hydroxy alprazolam. Intermediate precision was less than 4.1% over the tested concentration ranges. The method is the first reported application of HILIC in the analysis benzodiazepines in human plasma. With a small sample size (50µL human plasma) and a run time less than 10.0min for each sample the method can be used to support a wide range of clinical studies concerning alprazolam quantification.

Androgen glucuronides analysis by liquid chromatography tandem-mass spectrometry: could it raise new perspectives in the diagnostic field of hormone-dependent malignancies?

Breast and prostate constitute organs of intense steroidogenic activity. Clinical and epidemiologic data provide strong evidence on the influence of androgens and estrogens on the risk of typical hormone-dependent malignancies, like breast and prostate cancer. Recent studies have focused on the role of androgen metabolites in regulating androgen concentrations in hormone-sensitive tissues. Steroid glucuronidation has been suggested to have a prominent role in controlling the levels and the biological activity of unconjugated androgens. It is well-established that serum levels of androgen glucuronides reflect androgen metabolism in androgen-sensitive tissues. Quantitative analysis of androgen metabolites in blood specimens is the only minimally invasive approach permitting an accurate estimate of the total pool of androgens. During the past years, androgen glucuronides analysis most often involved radioimmunoassays (RIA) or direct immunoassays, both methods bearing serious limitations. However, recent impressive technical advances in mass spectrometry, and particularly in high performance liquid chromatography coupled with mass spectrometry (LC-MS/MS), have overcome these drawbacks enabling the simultaneous, quantitative analysis of multiple steroids even at low concentrations. Blood androgen profiling by LC-MS/MS, a robust and reliable technique of high selectivity, sensitivity, specificity, precision and accuracy emerges as a promising new approach in the study of human pathology. The present review offers a contemporary insight in androgen glucuronides profiling through the application of LC-MS/MS, highlighting new perspectives in the study of steroids and their implication in hormone-dependent malignancies.

A simple and sensitive GC/MS method for the determination of atropine during therapy of anticholinesterase poisoning in serum samples.

Atropine is used in the daily clinical practice for the treatment of poisonings caused by anticholinesterase pesticides, due to its sympathomimetic action. The investigation of the cause of the adverse effects that appear during atropine administration showed the necessity for the development and validation of a simple, rapid, sensitive, and specific method for the determination of atropine levels in serum samples. The developed method includes liquid-liquid extraction with ethyl acetate: dichloromethane (3:1, v/v) and derivatization using N,O-bis(trimethylsilyl)-trifluoracetamide (BSTFA) with 1% trimethylchlorsilane (TMCS) in acetonitrile environment. The method was found to be selective, linear, accurate, and precise according to international guidelines. The recovery was higher than 85.9%, the limit of quantification was 2.00 ng/ml, and the calibration curve was linear within the range of 2.00-500 ng/ml (R(2) ≥ 0.992). Accuracy and precision were also calculated and were found to be less than 5.2 and 8.7%, respectively. The developed method was applied in a real case of accidental poisoning with chlorpyrifos in order to determine the atropine serum levels of the patient. The proposed method proved to be useful for the investigation of adverse effects that appear during atropine treatment of patients poisoned by anticholinesterase pesticides and it can also be used for the investigation of poisonings caused after consumption of atropine containing plants.