共查询到20条相似文献,搜索用时 250 毫秒
1.
Chuixiu Huang Knut Fredrik Seip Astrid Gjelstad Stig Pedersen-Bjergaard 《Analytica chimica acta》2016
Electromembrane extraction (EME) of polar basic drugs from human plasma was investigated for the first time using pure bis(2-ethylhexyl) phosphite (DEHPi) as the supported liquid membrane (SLM). The polar basic drugs metaraminol, benzamidine, sotalol, phenylpropanolamine, ephedrine, and trimethoprim were selected as model analytes, and were extracted from 300 μL of human plasma, through 10 μL of DEHPi as SLM, and into 100 μL of 10 mM formic acid as acceptor solution. The extraction potential across the SLM was 100 V, and extractions were performed for 20 min. After EME, the acceptor solutions were analyzed by high-performance liquid chromatography-ultraviolet detection (HPLC-UV). In contrast to other SLMs reported for polar basic drugs in the literature, the SLM of DEHPi was highly stable in contact with plasma, and the system-current across the SLM was easily kept below 50 μA. Thus, electrolysis in the sample and acceptor solution was kept at an acceptable level with no detrimental consequences. For the polar model analytes, representing a log P range from −0.40 to 1.32, recoveries in the range 25–91% were obtained from human plasma. Strong hydrogen bonding and dipole interactions were probably responsible for efficient transfer of the model analytes into the SLM, and this is the first report on efficient EME of highly polar analytes without using any ionic carrier in the SLM. 相似文献
2.
In the present work, acidic and basic drugs were simultaneously extracted by a novel method of high efficiency herein referred to as two-step voltage dual electromembrane extraction (TSV-DEME). Optimizing effective parameters such as composition of organic liquid membrane, pH values of donor and acceptor solutions, voltage and duration of each step, the method had its figures of merit investigated in pure water, human plasma, wastewater, and breast milk samples. Simultaneous extraction of acidic and basic drugs was done by applying potentials of 150 V and 400 V for 6 min and 19 min as the first and second steps, respectively. The model compounds were extracted from 4 mL of sample solution (pH = 6) into 20 μL of each acceptor solution (32 mM NaOH for acidic drugs and 32 mM HCL for basic drugs). 1-Octanol was immobilized within the pores of a porous hollow fiber of polypropylene, as the supported liquid membrane (SLM) for acidic drugs, and 2-ethyle hexanol, as the SLM for basic drugs. The proposed TSV-DEME technique provided good linearity with the resulting correlation coefficients ranging from 0.993 to 0.998 over a concentration range of 1–1000 ng mL−1. The limit of detections of the drugs were found to range within 0.3–1.5 ng mL−1, while the corresponding repeatability ranged from 7.7 to 15.5% (n = 4). The proposed method was further compared to simple dual electromembrane extraction (DEME), indicating significantly higher recoveries for TSV-DEME procedure (38.1–68%), as compared to those of simple DEME procedure (17.7–46%). Finally, the optimized TSV-DEME was applied to extract and quantify model compounds in breast milk, wastewater, and plasma samples. 相似文献
3.
Nickolaj Jacob Petersen Henrik Jensen Steen Honoré Hansen Knut Einar Rasmussen Stig Pedersen-Bjergaard 《Journal of chromatography. A》2009,1216(9):1496-1502
Electromembrane extraction (EME) of basic drugs from 10 μL sample volumes was performed through an organic solvent (2-nitrophenyl octyl ether) immobilized as a supported liquid membrane (SLM) in the pores of a flat polypropylene membrane (25 μm thickness), and into 10 μL 10 mM HCl as the acceptor solution. The driving force for the extractions was 3–20 V d.c. potential sustained over the SLM. The influence of the membrane thickness, extraction time, and voltage was investigated, and a theory for the extraction kinetics is proposed. Pethidine, nortriptyline, methadone, haloperidol, and loperamide were extracted from pure water samples with recoveries ranging between 33% and 47% after only 5 min of operation under totally stagnant conditions. The extraction system was compatible with human urine and plasma samples and provided very efficient sample pretreatment, as acidic, neutral, and polar substances with no distribution into the organic SLM were not extracted across the membrane. Evaluation was performed for human urine, providing linearity in the range 1–20 μg/mL, and repeatability (RSD) in average within 12%. 相似文献
4.
De La Rosa Luis B. Reshamwala Sultan Latimer Vivian M. Shawky Bahaa T. Dale Bruce E. Stuart Earnest D. 《Applied biochemistry and biotechnology》1994,(1):483-497
The herbaceous crops that may provide fermentable carbohydrates for production of fuels and chemicals also contain 10–20%
protein. Protein coproduction with biomass-derived fuels and chemicals has important advantages: (1) food and fuel production
can be integrated, and (2) protein is a high-value product that may significantly improve overall process economics. We report
the results of an integrated approach to producing protein and fermentable sugars from one herbaceous species, Coastal Bermudagrass
(CBG). The ammonia fiber explosion (AFEX) process makes possible over 90% conversion of cellulose and hemicellulose to simple
sugars (about 650 mg reducing sugars/g dry CBG) at 5 IU cellulase/g vs < 20% conversion for untreated CBG. The AFEX treatment
also improves protein extraction from CBG; over 80% protein recovery is possible from AFEX-treated CBG vs about 30% recovery
from untreated CBG. 相似文献
5.
Planar polyamide 6 nanofibrous membrane was for the first time used in direct coupling of supported liquid membrane (SLM) extraction to CE analysis. Disposable microextraction device with the nanofibrous membrane was preassembled and stored for immediate use. The membrane in the device was impregnated with 1 µL of 1‐ethyl‐2‐nitrobenzene and the device was subsequently filled with 10 µL of acceptor solution (10 mM HCl) and 15 µL of donor solution (sample). The device was in‐line coupled to CE system for selective extraction and direct injection, separation and quantification of model basic drugs (nortriptyline, haloperidol, loperamide and papaverine) from standard saline solutions (150 mM NaCl) and from undiluted human body fluids (urine and blood plasma). Compared to standard polypropylene supporting material, the nanofibrous membrane demonstrated superior characteristics in terms of lower consumption of organic solvents, constant volumes of operational solutions, full transparency and possibility to preassemble the devices. Extraction parameters were better or comparable for the nanofibrous vs. the polypropylene membrane and the hyphenated SLM‐CE method with the nanofibrous membrane was characterized by good repeatability (RSD ≤ 11.3%), linearity (r2 ≥ 0.9953; 0.5–20 mg/L), sensitivity (LOD ≤ 0.4 mg/L) and transfer (27–126%) of the basic drugs. 相似文献
6.
Surfactant‐assisted electromembrane extraction combined with capillary electrophoresis as a novel technique for the determination of acidic drugs in biological fluids
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Ali Reza Fakhari Kobra Sadat Hasheminasab Zolfaghar Aladaghlo Mohammad Hosein Koruni 《Electrophoresis》2015,36(24):3034-3041
In this paper, for the first time, surfactant‐assisted electromembrane extraction coupled with capillary electrophoresis with UV detector was introduced for the extraction of acidic drugs from biological fluids. In this technique, in the presence of the nonionic surfactant in the donor phase, tendency of analyte ions into the supported liquid membrane (SLM) was increased. Naproxen and diclofenac were selected as model acidic drugs. In order to obtain the best extraction efficiency, several factors influencing the extraction efficiency were investigated. Optimal extractions were accomplished with 1‐octanol as the SLM, 15 Volt dc potential as the driving force, pH 12 in acceptor solution, and 0.2 mmol/L Triton X‐100 with pH 7.4 in donor solution. Equilibrium extraction conditions were obtained after 15 min of operation where the whole assembly agitated at 1000 rpm. Under the optimized conditions, preconcentration factors in the range of 176–184 and recoveries in the range of 88–92% were obtained. The applied method offers acceptable linearity with correlation coefficients higher than 0.9992. Limits of detection of 1.51 ng/mL and 2.42 ng/mL were obtained for naproxen and diclofenac, respectively. Finally, the developed method was successfully applied for the determination of naproxen and diclofenac in different matrices including plasma and urine samples. 相似文献
7.
Middelthon-Bruer TM Gjelstad A Rasmussen KE Pedersen-Bjergaard S 《Journal of separation science》2008,31(4):753-759
Thirty-five different basic drugs were extracted by electro membrane extraction (EME), from acidified samples containing HCl as the BGE, through an organic solvent immobilized in the pores in the wall of a porous hollow fiber (supported liquid membrane, SLM), and into an acidified acceptor solution (HCl) in the lumen of the hollow fiber by the application of an electrical potential difference of 50 V. With 2-nitrophenyl pentyl ether (NPPE) as the SLM, and with 10 mM HCl as BGE in the sample and acceptor solution, singly charged basic drugs with log P >2 were extracted with recoveries in the range 30-81% within 5 min. For doubly charged basic drugs, extraction was effectively enhanced by decreasing the concentration of HCl in the sample from 10 to 0.1 mM, reducing the ionization of the analytes. For medium polar analytes (1 < log P < 2), an ion balance of 0.01 was combined with addition of tris-(2-ethylhexyl) phosphate (TEHP) to the SLM, and this provided recoveries in the range 36-70%. The ion balance was defined as the concentration ratio of BGE between the sample and the acceptor solution. For the most polar drugs (log P <1), EME was accomplished with an ion balance of 0.01 and with di-(2-ethylhexyl) phosphate (DEHP) added to the SLM, but in spite of this, recoveries were in the range of only 4-17%. 相似文献
8.
Cristina Roman‐Hidalgo Elia Santigosa‐Murillo María Ramos‐Payn Nickolaj J. Petersen Jrg P. Kutter Stig Pedersen‐Bjergaard 《Electrophoresis》2019,40(18-19):2514-2521
In the present work, a new supported liquid membrane (SLM) has been developed for on‐chip electromembrane extraction of acidic drugs combined with HPLC or CE, providing significantly higher stability than those reported up to date. The target analytes are five widely used non‐steroidal anti‐inflammatory drugs (NSAIDs): ibuprofen (IBU), diclofenac (DIC), naproxen (NAX), ketoprofen (KTP) and salicylic acid (SAL). Two different microchip devices were used, both consisted basically of two poly(methyl methacrylate) (PMMA) plates with individual channels for acceptor and sample solutions, respectively, and a 25 µm thick porous polypropylene membrane impregnated with the organic solvent in between. The SLM consisting of a mixture of 1‐undecanol and 2‐nitrophenyl octyl ether (NPOE) in a ratio 1:3 was found to be the most suitable liquid membrane for the extraction of these acidic drugs under dynamic conditions. It showed a long‐term stability of at least 8 hours, a low system current around 20 µA, and recoveries over 94% for the target analytes. NPOE was included in the SLM to significantly decrease the extraction current compared to pure 1‐undecanol, while the extraction properties was almost unaffected. Moreover, it has been successfully applied to the determination of the target analytes in human urine samples, providing high extraction efficiency. 相似文献
9.
Electro-assisted extraction of ionic drugs from biological fluids through a supported liquid membrane (SLM) and into an aqueous acceptor solution was recently introduced as a new sample preparation technique termed electromembrane extraction (EME). The applied electrical potential across the SLM has typically been in the range of 1-300 V. Successful extractions have been demonstrated even with common batteries (9 V) instead of a power supply. The chemical composition of the SLM has been crucial for the selectivity and for the recoveries of the extraction. Compared to other liquid-phase microextraction techniques (LPME), extraction times have been reduced by a factor of 6-17, and successful extractions have been obtained at extraction times of 1-5 min, and even down to a few seconds with online microfluidic EME devices. The technique has provided very efficient sample clean-up and has been found well suited for the extraction of sample sizes in the low μL range. Extractions have been performed with both rod-shaped hydrophobic porous fibers and with flat hydrophobic porous sheets as SLM support. The technique has been successfully downscaled into the micro-chip format. The nature of the SLM has been tuned for extraction of drugs with different polarity allowing extractions to be tailored for specific applications depending on the analyte of interest. The technique has been found to be compatible with a wide range of biological fluids and extraction of drugs directly from untreated human plasma and whole blood has been demonstrated. EME selectively extracts the compounds from the complex biological sample matrix as well as allowing concentration of the drugs. With home-built equipment fully acceptable validation results have been obtained. 相似文献
10.
Lars Erik Eng Eibak Astrid Gjelstad Knut Einar Rasmussen Stig Pedersen-Bjergaard 《Journal of chromatography. A》2010,1217(31):5050-5056
Amitriptyline, citalopram, fluoxetine, and fluvoxamine were isolated by electro membrane extraction (EME) from 70 μl of untreated plasma (pH 7.4), through a supported liquid membrane (SLM) of 1-ethyl-2-nitrobenzene immobilized in the pores of a porous polypropylene hollow fiber, and into 30 μl of 10 mM HCOOH as acceptor solution inside the lumen of the hollow fiber. The driving force of the extraction was a 9 V potential sustained over the SLM with a common battery, with the positive electrode placed in the plasma sample and the negative electrode placed in the acceptor solution. Extractions were performed under totally stagnant conditions with a very simple device for 1 min (kinetic regime), and subsequently the acceptor solution was analyzed directly by liquid chromatography–mass spectrometry (LC–MS). Recoveries were 12, 13, 22, and 17% for fluoxetine, amitriptyline, citalopram, and fluvoxamine, respectively. Sample clean-up was comparable to reversed-phase solid-phase extraction (SPE), but EME required substantially less time than SPE. The time advantage of EME was further improved by parallel extraction of three samples (for 1 min) with the same 9 V battery. EME from plasma combined with LC–MS provided limits of quantification (S/N = 10) in the range 0.4–2.3 ng/ml, linearity in the range 1–1000 ng/ml with r2-values of 0.998–0.999, and repeatability in the range 3.2–8.9% RSD in the mid-therapeutic window (100 ng/ml). 相似文献
11.
P. López S. Martello A. M. Bermejo Eleonora De Vincenzi M. J. Tabernero M. Chiarotti 《Analytical and bioanalytical chemistry》2010,397(4):1539-1548
This article describes an easy and innovative extraction procedure for cocaine and its primary metabolite, benzoylecgonine
(BE), from hair consisting of sonication with H2O/0.1% formic acid for 4 h. The same extract was used for screening with an enzyme-linked immunoassay (ELISA) and confirmation
by liquid chromatography–tandem mass spectrometry (LC–MS/MS). For the ELISA screening test a cutoff of 0.5 ng/mg was used
according to the Society of Hair Testing recommendations. LC–MS/MS limits of detection (LODs) were established to be 10 pg/mg
and 1 pg/mg for cocaine and BE, respectively. Linearity was obtained over a range of 0.2–5 ng/mg for BE (target analyte) in
the ELISA screening test, while in the LC–MS/MS method the range was 0.10–10 ng/mg for cocaine and 0.01–10 ng/mg for BE. Intra-
and interbatch coefficients of variation and mean relative errors were less than 20% for all analytes and concentrations studied.
The validated ELISA and LC–MS/MS methods were applied to 48 hair samples and the results of both methods were compared; ELISA
demonstrated a sensitivity and specificity of 89.2% and 10.8%. 相似文献
12.
Ana Fortuna Joana Sousa Gilberto Alves Amílcar Falcão Patrício Soares-da-Silva 《Analytical and bioanalytical chemistry》2010,397(4):1605-1615
For the first time, a simple, selective and accurate high-performance liquid chromatography method with ultraviolet detection
was developed and validated to quantify simultaneously three structurally related antiepileptic drugs; carbamazepine, oxcarbazepine,
and the recently launched eslicarbazepine acetate and their main metabolites, carbamazepine-10,11-epoxide, 10,11-trans-dihydroxy-10,11-dihydro-carbamazepine, and licarbazepine. The method involves a solid-phase extraction and a reverse-phase
C18 column with 5 cm length. The mobile phase consisting of water, methanol, and acetonitrile in the ratio 64:30:6 was selected
as the best one and pumped at 1 mL/min at 40 °C. The use of this recent column and an aqueous mobile phase instead of buffers
gives several advantages over the method herein developed; namely the fact that the chromatographic analysis takes only 9 min.
The method was validated according to the guidelines of the Food and Drug Administration, showing to be accurate (bias within
±12%), precise (coefficient variation <9%), selective and linear (r
2 > 0.997) over the concentration range of 0.05–30 μg/mL for carbamazepine; 0.05–20 μg/mL for oxcarbazepine; 0.15–4 μg/mL for
eslicarbazepine acetate; 0.1–30 μg/mL for carbamazepine-10,11-epoxide; 0.1–10 μg/mL for 10,11-trans-dihydroxy-10,11-dihydro-carbamazepine, and 0.1–60 μg/mL for licarbazepine. It was also shown that this method can adequately
be used for the therapeutic drug monitoring of the considered antiepileptic drugs, carbamazepine, oxcarbazepine, eslicarazepine
acetate, and their metabolites. 相似文献
13.
Kjelsen IJ Gjelstad A Rasmussen KE Pedersen-Bjergaard S 《Journal of chromatography. A》2008,1180(1-2):1-9
The present work has for the first time demonstrated electromembrane extraction (EME) at voltages obtainable by common batteries. Five basic drugs were extracted from acidified aqueous sample solutions, across a supported liquid membrane (SLM) consisting of 1-isopropyl-4-nitrobenzene impregnated in the walls of a hollow fiber, and into an acidified aqueous acceptor solution present inside the lumen of the hollow fiber with potential differences of 1-10 V applied over the SLM. Extractions from 1 ml standard solutions prepared in 10mM HCl for 5 min and with a potential of 10 V demonstrated analyte recoveries of 50-93% in 25 microl of 10mM HCl as acceptor solution. This corresponds to enrichment factors of 20-37. Similar results were obtained with a common 9 V battery as power supply. Recoveries from low-voltage EME on human plasma, urine, and breast milk diluted with acetate buffer (pH 4) demonstrated recoveries in the range of 37-55% after 5 min of extraction. Excellent selectivity was demonstrated as no interfering peaks were detected. Standard curves in the range of 0.0625-0.62 5 microg/ml demonstrated correlation coefficients of 0.994-0.999. Extraction recoveries from human plasma, urine or breast milk were not found to be sensitive towards individual variations. The results show that low-voltage EME has a future potential as a simple, selective, and time-efficient sample preparation technique of biological fluids. 相似文献
14.
Determination of triazine herbicides in human body fluids by solid-phase microextraction and capillary gas chromatography 总被引:2,自引:0,他引:2
T. Kumazawa X. -P. Lee K. Kondo K. Sato H. Seno K. Watanabe-Suzuki A. Ishii O. Suzuki 《Chromatographia》2000,52(3-4):195-199
Summary Eight triazine herbicides, prometon, propazine, atrazine, simazine, prometryn, ametryn, metribuzin, and cyanazine, have been
extracted from human whole blood and urine samples by headspace solid-phase microextraction (SPME) with a polydimethylsiloxane-coated
fiber and quantified by capillary gas chromatography with nitrogen-phosphorus detection.
Extraction efficiencies for all compounds were 0.21–0.99% for whole blood, except for cyanazine (0.06%). For urine, the extraction
efficiencies for prometon, propazine, atrazine, prometryn and ametryn were 13.6–38.1%, and those of simazine, metribuzin and
cyanazine were 1.35–8.73%.
The regression equations for the compounds extracted from whole blood were linear within the concentration ranged 0.01–1 μg
(0.5 mL)−1 for prometon, propazine, atrazine, prometryn, and ametryn, and 0.02–1 μg (0.5 mL)−1 for simazine, metribuzin, and cyanazine. For urine, regression equations for all compounds were linear within the concentration
range 0.005–0.25 μg mL−1. Compound detection limits were 2.8–9.0 ng (0.5 mL)−1 and 0.4–2.0 ng mL−1 for whole blood and urine, respectively. The coefficients of within-day and day-to-day variation were satisfactory for all
the compounds, and not greater than 10.3 and 14.2%, respectively.
Data obtained from determination of atrazine in rat whole blood after oral administration of the compound are also presented. 相似文献
15.
The first method for quantifying cannabinoids and cannabinoid glucuronides in whole blood by liquid chromatography–tandem
mass spectrometry (LC–MS/MS) was developed and validated. Solid-phase extraction followed protein precipitation with acetonitrile.
High-performance liquid chromatography separation was achieved in 16 min via gradient elution. Electrospray ionization was
utilized for cannabinoid detection; both positive (Δ9-tetrahydrocannabinol [THC] and cannabinol [CBN]) and negative (11-hydroxy-THC [11-OH-THC], 11-nor-9-carboxy-THC [THCCOOH],
cannabidiol [CBD], THC-glucuronide, and THCCOOH-glucuronide) polarity were employed with multiple reaction monitoring. Calibration
by linear regression analysis utilized deuterium-labeled internal standards and a 1/x
2 weighting factor, yielding R
2 values >0.997 for all analytes. Linearity ranged from 0.5 to 50 μg/L (THC-glucuronide), 1.0–100 μg/L (THC, 11-OH-THC, THCCOOH,
CBD, and CBN), and 5.0–250 μg/L (THCCOOH-glucuronide). Imprecision was <10.5% CV, recovery was >50.5%, and bias within ±13.1%
of target for all analytes at three concentrations across the linear range. No carryover and endogenous or exogenous interferences
were observed. This new analytical method should be useful for quantifying cannabinoids in whole blood and further investigating
cannabinoid glucuronides as markers of recent cannabis intake. 相似文献
16.
A sensitive LC-MS/MS assay for quantification of total and free concentrations of R- and S-warfarin in plasma was required
to support clinical studies on warfarin enantiomers. Several ultrafiltration devices were evaluated for separation of free
warfarin from plasma proteins. The highest precision and lowest non-specific binding was obtained for Centrifree ultrafiltration
devices. R- and S-warfarin were extracted from plasma (total) and ultrafiltrate (free) by liquid–liquid extraction with methyl
tert-butyl ether using d6-warfarin as internal standard. Mean extraction recovery was 68 ± 4%. The enantiomers were separated on a Chirobiotic V column
with isocratic elution using 40% methanol and 0.03% acetic acid in water. Negative mode electrospray ionisation was used for
MS/MS detection, monitoring the ion transition m/z 307/161. Calibration curves (quadratic, weighted 1/x) were fitted over the range of 20–2,000 ng/ml (r
2 ≥ 0.995) in plasma and 0.5–20 ng/ml (r
2 ≥ 0.998) in ultrafiltrate. The lower limit of quantification for R- and S-warfarin was 0.5 ng/ml in ultrafiltrate. Intra-
and interday precision (% RSD) and bias were within 10% in all cases, and matrix effects were negligible. The assay was applied
successfully to analysis of samples from clinical studies. 相似文献
17.
I. V. Pletnev Nataliya V. Shvedene Irina V. Lyutikova Inna A. Nazarova Ilya M. Litvak Irina V. Mikhura Yury A. Zolotov 《Fresenius' Journal of Analytical Chemistry》1999,364(8):682-685
Arylboronic acids are used as novel carriers for membrane electrodes suitable for direct potentiometric determination of
the catecholamine drug dobutamine. The carriers are capable of binding diol groups of catecholamines; solvent extraction data
confirm the formation of an 1 : 1 complex. For the electrode based on octyloxyphenylboronic acid, the slope of electrode function
is S = 58 mV decade–1; the detection limit is 1.7 · 10–5 mol/L, the linear range 5 · 10–4– 1 · 10–2 mol/L, the response time 10–20 s. The results suggest the potential use of boronic carriers for the detection of biogenic
catecholamines.
Received: 25 November 1998 / Revised: 2 March 1999 / Accepted: 11 March 1999 相似文献
18.
A novel method based on three-phase hollow fiber microextraction technique (HF-LPME) coupled with electrospray ionization-ion
mobility spectrometry (ESI-IMS) was developed for the simultaneous determination of two antidepressant drugs (trimipramine
and desipramine) in urine and plasma samples. The effects of various parameters such as type of organic solvent, composition
of donor and acceptor phase, stirring rate, salt addition, extraction time, and temperature were investigated. Under the optimized
conditions, the relative standard deviation was in the range of 5–6%, and the method quantitation limit (MQL) of utilizing
HF-LPME/ESI-IMS was 5 μg/L for both drugs. The relative recoveries obtained by the proposed method from urine and plasma samples
were in the range 94% to 97% for trimipramine and 92% to 96% for desipramine. Finally, the feasibility of the proposed method
was successfully confirmed by extraction and determination of trace amounts of trimipramine and desipramine in biological
samples without any significant matrix effect. 相似文献
19.
K. Watanabe H. Hattori M. Nishikawa A. Ishii T. Kumazawa H. Seno O. Suzuki 《Chromatographia》1997,44(1-2):55-58
Summary Cocaethylene together with cocaine spiked in human whole blood has been found measurable at high sensitivities by capillary
gas chromatography with surface ionization detection. The drugs could be rapidly extracted by Sep-Pak C18 cartridges with recovery of more than 60%. The calibration curves for both cocaethylene and cocaine using cocapropylene as
internal standard were linear in the range 50–300 pmol mL−1 of whole blood. The detection limits of cocaethylene and cocaine were 5–10 pmol mL−1 (0.1–0.2 pmol on column if recovery is 100%). Cocaethylene could be determined for whole blood obtained from rats (ca. 200
g body wt.), which had received subcutaneous injection of 10 mg cocaine hydrochloride and 2.0 mL of 30% (v/v) ethanol 3 h
before sampling; the mean levels of cocaethylene and cocaine were 101 and 1230 pmol mL−1, respectively. 相似文献
20.
Benzylpiperazine (BZP) is an amphetamine-type stimulant, which was legally available in New Zealand and widely used in “Party
Pills” until reclassification as a Class C drug in April 2008. BZP was included as part of a multi-analyte method developed
for hair screening using high-performance liquid chromatography triple quadrupole mass spectrometry (LC-MS/MS). A 20-mg sample
of hair is extracted and partially purified using mixed-mode solid-phase extraction cartridges prior to analysis by LC-MS/MS.
The method was developed as a broad screen for drugs of abuse (including amphetamines, opiates, and benzodiazepines), with
only the BZP results being presented here. The assay was validated and found to be linear over the range of 0.085 to 8.65 ng/mg
with correlation coefficient of r
2 ≥ 0.99. Blank hair samples spiked with BZP at 0.22 and 2.16 ng/mg gave intra- and inter-day precision coefficients of variation
of ≤10% (n = 6 per day, 3 days) at both levels and calculated extraction efficiencies of 78% and 91%, respectively. The results from
the samples submitted to the laboratory for BZP analysis showed 11% were positive (n = 126). The mean BZP level was 3.9 ng/mg (range, 0.4–33 ng/mg; the result was extrapolated when above the calibration). These
data are the first available showing the levels expected from users of BZP. 相似文献