共查询到20条相似文献,搜索用时 125 毫秒
1.
A novel molecularly imprinted polymer solid-phase extraction (MISPE) with flow-injection chemiluminescence (CL) was developed
for the determination of pazufloxacin mesilate (PZFX). The molecularly imprinted polymer (MIP) was synthesized by using PZFX
as the imprinting molecule. A glass tube packed the particles of the MIP was employed as MISPE micro-column, which was connected
into the sampling loop of the eight-way injection valve for on-line selective preconcentration and extraction of PZFX. The
eluent of acetonitrile:acetic acid (9:1, v:v) was used as carrier for eluting the adsorbed PZFX to react with the mixture
of cerium(IV) and sodium sulfite in the flow cell to produce strong CL. The relative intensity of CL was linear to PZFX concentration
in the range from 2.5 × 10−9 to 2.5 × 10−7 g mL−1. The limit of detection was 7 × 10−10 g mL−1 (3 σ) and the relative standard deviation for 5 × 10−8 g mL−1of PZFX solution was 3.7% (n = 7). This method has been applied to the determination of PZFX in human urine. 相似文献
2.
Feng QZ Zhao LX Yan W Ji F Wei YL Lin JM 《Analytical and bioanalytical chemistry》2008,391(3):1073-1079
Highly sensitive flow-injection chemiluminescence (CL) combined with molecularly imprinted solid-phase extraction (MISPE)
has been used for determination of 2,4-dichlorophenol (2,4-DCP) in water samples. The molecularly imprinted polymer (MIP)
for 2,4-DCP was prepared by non-covalent molecular imprinting methods, using 4-vinylpyridine (4-VP) and ethylene glycol dimethacrylate
(EGDMA) as the monomer and cross-linker, respectively. 2,4-DCP could be selectively adsorbed by the MIP and the adsorbed 2,4-DCP
was determined by its enhancing effect on the weak chemiluminescence reaction between potassium permanganate and luminol.
The enhanced CL intensity was linear in the range from 1 × 10−7 to 2 × 10−5g mL−1. The LOD (S/N = 3) was 1.8 × 10−8g mL−1, and the relative standard deviation (RSD) was 3.0% (n = 11) for 1.4 × 10−6g mL−1. The proposed method had been successfully applied to the determination of 2,4-DCP in river water.
Figure Effect of 4-VP content on the ultraviolet spectrum of 2,4-DCP in chloroform 相似文献
3.
Development of a selective molecularly imprinted polymer-based solid-phase extraction for indomethacin from water samples 总被引:1,自引:0,他引:1
A selective molecularly imprinted solid-phase extraction (MISPE) for indomethacin (IDM) from water samples was developed.
Using IDM as template molecule, acrylamide (AM) or methacrylic acid (MAA) as functional monomer, ethylene dimethacrylate (EDMA)
as crosslinker, and bulk or suspension polymerization as the synthetic method, three molecularly imprinted polymers (MIPs)
were synthesized and characterized with a rebinding experiment. It was found that the MIP of AM-EDMA produced by bulk polymerization
showed the highest binding capacity for IDM, and so it was chosen for subsequent experiments, such as those testing the selectivity
and recognition binding sites. Scatchard analysis revealed that at least two kinds of binding sites formed in the MIP, with
the dissociation constants of 7.8 μmol L−1 and 127.2 μmol L−1, respectively. Besides IDM, three structurally related compounds — acemetacin, oxaprozin and ibuprofen — were employed for
selectivity tests. It was observed that the MIP exhibited the highest selective rebinding to IDM. Accordingly, the MIP was
used as a solid-phase extraction sorbent for the extraction and enrichment of IDM in water samples. The extraction conditions
of the MISPE column for IDM were optimized to be: chloroform or water as loading solvent, chloroform with 20% acetonitrile
as washing solution, and methanol as eluting solvent. Water samples with or without spiking were extracted by the MISPE column
and analyzed by HPLC. No detectable IDM was observed in tap water and the content of IDM in a river water sample was found
to be 1.8 ng mL−1. The extraction efficiencies of the MISPE column for IDM in spiked tap and river water were acceptable (87.2% and 83.5%,
respectively), demonstrating the feasibility of the prepared MIP for IDM extraction.
Figure Molecularly imprinted polymer-based solid-phase extraction for indomethacin 相似文献
4.
San Vicente B Navarro Villoslada F Moreno-Bondi MC 《Analytical and bioanalytical chemistry》2004,380(1):115-122
A bisphenol A (BPA) molecularly imprinted polymer, the composition of which was optimised using a chemometric approach, has been applied to the selective preconcentration of the template from aqueous samples. The selectivity of the polymer toward BPA and related compounds was evaluated chromatographically. The BPA-imprinted polymer was packed in a column and used for continuous on-column solid-phase extraction (MISPE) of aqueous samples followed by subsequent analysis by HPLC with fluorescence detection of the eluted fractions. The composition of the washing solvent applied in the MISPE procedure was optimised to favour the specific interactions of the MIP with BPA and to remove the non-selectively bound matrix components. The MISPE method has proven to be effective for selective preconcentration of BPA in aqueous samples (recoveries >84% obtained in the eluate for 10–100 mL sample volumes) enabling detection and quantification limits of 1.0 and 3.3 ng mL–1, respectively (based on 25 mL sample size). Analytical recoveries were between 92 and 101% for river water samples spiked with known amounts of BPA (30, 60, and 80 ng mL–1); relative standard deviations (RSD) were lower than 5.0%. 相似文献
5.
Guzmán-Vázquez de Prada A Loaiza OA Serra B Morales D Martínez-Ruiz P Reviejo AJ Pingarrón JM 《Analytical and bioanalytical chemistry》2007,388(1):227-234
A molecularly imprinted polymer was developed and used for solid-phase extraction (MISPE) of the antihelmintic fenbendazole
in beef liver samples. Detection of the analyte was accomplished using square wave voltammetry (SWV) at a cylindrical carbon
fibre microelectrode (CFME). A mixture of MeOH/HAc (9:1) was employed both as eluent in the MISPE system and as working medium
for electrochemical detection of fenbendazole. The limit of detection was 1.9 × 10−7 mol L−1 (57 μg L−1), which was appropriate for the determination of fenbendazole at the maximum residue level permitted by the European Commission
(500 μg kg−1 in liver). Given that the SW voltammetric analysis could not be directly performed in the sample extract as a consequence
of interference from some sample components, a sample clean-up with a MIP for selectively retaining fenbendazole was performed.
The MIP was synthesized using a 1:8:22 template/methacrylic acid/ethylene glycol dimethacrylate ratio. A Britton–Robinson
Buffer of pH 9.0 was selected for retaining fenbendazole in the MIP cartridges, and an eluent volume of 5.0 mL at a flow rate
of 2.0 mL min−1 was chosen in the elution step. Cross-reactivity with the MIP was observed for other benzimidazoles. The synthesized MIP
exhibited a good selectivity for benzimidazoles with respect to other veterinary drugs. The applicability of the MISPE-SWV
method was tested with beef liver samples, spiked with fenbendazole at 5,000 and 500 μg kg−1. Results obtained for ten different liver samples yielded mean recoveries of (95 ± 12)% and (96 ± 11)% for the upper and
lower concentration level, respectively. 相似文献
6.
A rapid, specific, and sensitive method has been developed using molecularly imprinted polymers (MIPs) as solid-phase extraction
sorbents for extraction of trace tetracycline antibiotics (TCs) in foodstuffs. MIPs were prepared by precipitation polymerization
using tetracycline as the template. Under the optimal condition, the imprinting factors for MIPs were 4.1 (oxytetracycline),
7.0 (tetracycline), 7.4 (chlortetracycline), 7.7 (doxycycline), respectively. Furthermore, the performance of MIPs as solid-phase
extraction sorbents was evaluated and high extraction efficiency of molecularly imprinted solid-phase extraction (MISPE) procedure
was demonstrated. Compared with commercial sorbents, MISPE gave a better cleanup efficiency than C18 cartridge and a higher
recovery than Oasis HLB cartridge. Finally, the method of liquid chromatography–tandem mass spectrometry coupled with molecular-imprinted
solid-phase extraction was validated in real samples including lobster, duck, honey, and egg. The spiked recoveries of TCs
ranged from 94.51% to 103.0%. The limits of detection were in the range of 0.1–0.3 μg kg−1.
Chromatograms obtained by direct injection of the spiked egg extracts (5 × 10-3 mmol L−1) and purification with MISPE 相似文献
7.
A novel and simple chemiluminescence (CL) method has been developed and validated for determination of metformin. This method
is based on hydroxyl radical chemiluminescence—the hydroxyl radical generated by reaction of Cu(II) and hydrogen peroxide
oxidizes rhodamine B (RhB) to produce weak CL which can be enhanced by metformin. At the same time, metformin molecularly
imprinted polymer (MIP) was synthesized. After enrichment based on the selectivity of metformin-MIP, the CL method was successfully
applied to the determination of metformin in human serum. The linear range was from 1.0×10−8 to 1.0×10−6 g mL−1 and the detection limit was 4×10−9 g mL−1. The relative standard deviation at 2.0×10−7 g mL−1 by use of MIP was 3.67% (n=7). 相似文献
8.
A new molecularly imprinted polymer for selective extraction of cotinine from urine samples by solid-phase extraction 总被引:1,自引:0,他引:1
Cotinine, the main metabolite of nicotine in human body, is widely used as a biomarker for assessment of direct or passive
exposure to tobacco smoke. A method for molecularly imprinted solid-phase extraction (MISPE) of cotinine from human urine
has been investigated. The molecularly imprinted polymer (MIP) with good selectivity and affinity for cotinine was synthesized
using cotinine as the template molecule, methacrylic acid as the functional monomer, and ethylene glycol dimethacrylate as
the cross-linker. The imprinted polymer was evaluated for use as a SPE sorbent, in tests with aqueous standards, by comparing
recovery data obtained using the imprinted form of the polymer and a non-imprinted form (NIP). Extraction from the aqueous
solutions resulted in more than 80% recovery. A range of linearity for cotinine between 0.05 and 5 μg mL−1 was obtained by loading 1 mL blank urine samples spiked with cotinine at different concentrations in acetate buffer of pH
9.0, and by using double basic washing and acidic elution. The intra-day coefficient of variation (CV) was below 7% and inter-day
CV was below 10%. This investigation has provided a reliable MISPE–HPLC method for determination of cotinine in human urine
from both active smokers and passive smokers.
Figure 相似文献
9.
An electrochemical creatinine sensor based on a molecularly imprinted polymer (MIP)‐modified sol‐gel film on graphite electrode was developed. The surface coating of MIP over sol‐gel was advantageous to obtain a porous film with outwardly exposed MIP cavities for unhindered selective rebinding of creatinine from aqueous and biological samples. A fast differential pulse, cathodic stripping voltammetric response of creatinine can be obtained after being preanodized the sensor in neutral medium containing appropriate amount of creatinine at +1.8 V versus SCE for 120 s. A linear response over creatinine concentration in the range of 1.23 to 100 μg mL?1 was exhibited with a detection limit of 0.37 μg mL?1 (S/N=3). 相似文献
10.
Preparation of highly selective solid-phase extractants for Cibacron reactive dyes using molecularly imprinted polymers 总被引:1,自引:0,他引:1
Yahya S. Al-Degs Adnan S. Abu-Surrah Khalid A. Ibrahim 《Analytical and bioanalytical chemistry》2009,393(3):1055-1062
Selective polymeric extractants were prepared for preconcentration of Cibacron reactive red dye, a dye that is often applied
with Cibacron reactive blue and Cibacron reactive yellow for dyeing of fabrics. The best extractant was fabricated (in chloroform)
using methacrylic acid (as monomer), ethylene glycol dimethacrylate (as crosslinker), AIBN (as initiator for polymerization),
and red dye as template molecule, with a molar stoichiometric ratio of 8.0:40.0:2.5:0.63, respectively. The structure of the
molecularly imprinted polymer (MIP) was robust, and resisted dissolution up to 260 °C. Compared with the un-imprinted polymer,
the imprinted product has a large specific surface area which improved its adsorption capacity. The effect of imprinting was
obvious from the adsorption capacity measured at pH 4 for red dye (the imprinted molecule), which was increased from 24.0
to 79.3 mg g−1 after imprinting. Equilibrium adsorption studies revealed that the dye-imprinted-polymer enables efficient extraction of
red dye even in the presence of blue and yellow dyes which have similar chemical natures to the red dye. The selectivity coefficients
S
red dye/dye, were 13.9 and 17.1 relative to the yellow and blue dyes, respectively. The MIP was found to be effective for red dye preconcentration,
with a preconcentration factor of 100, from tap water and treated textile wastewater. The factors affecting extraction of
red dye by the MIP were studied and optimized. Under the optimized extraction conditions, red dye was selectively quantified
in the presence of other competing dyes at a concentration of 20 μg L−1 from different water systems with satisfactory recoveries (91–95%) and RSD values (∼5.0%). 相似文献
11.
A novel capacitive sensor for pazufloxacin mesilate (pazufloxacin) determination was developed by electropolymerizing p-aminobenzene sulfonic (p-ABSA) and molecularly imprinted polymers (MPs), which was synthesized through thermal radical copolymerization of metharylic
acid (MAA) and ethylene glycol dimethacrylate (EGDMA) in the presence of pazufloxacin template molecules, on the gold electrode
surface. Furthermore, 1-dedecanethiol was used to insulate the modified electrode. Alternating current (ac) impedance experiments
were carried out with a Model IM6e to obtain the capacitance responses. Under the optimum conditions, the sensor showed linear
capacitance response to pazufloxacin in the range of 5 ng·mL−1 to 5 μg·mL−1 with a relative standard deviation (RSD) 5.3% (n=7) and a detection limit of 1.8 ng·mL−1. The recoveries for different concentration levels of pazufloxacin samples varied from 94.0% to 102.0%. Electrochemical experiments
indicated the capacitive sensor exhibited good sensitivity and selectivity and showed excellent parameters of regeneration
and stability.
Supported by the National Natural Science Foundation of China (Grant No. 20675064), the Natural Science Foundation of Chongqing
City (Grant No. CSTC-2004BB4149 and 2005BB4100) and High Technology Project Foundation of Southwest University (Grant No.
XSGX02). 相似文献
12.
《Analytical letters》2012,45(18):2896-2913
AbstractA highly selective and effective method for the purification and preconcentration of norfloxacin (NFX) in seawater samples was developed based on molecularly imprinted solid-phase extraction (MISPE). The molecularly imprinted polymer was synthesized by precipitation polymerization. Methacrylic acid (MAA) and ethylene glycol dimethacrylate (EGDMA) were used as the functional monomer and crosslinker, respectively. The resulting molecularly imprinted polymer (MIP) showed high adsorption for NFX and was selective for its solid-phase extraction. An offline MISPE method followed by high performance liquid chromatography with diode array detection was established for the determination of NFX in seawater. The recoveries of spiked seawater samples using the MISPE columns were satisfactorily higher than 77.6%. The relative standard deviation was less than 5.60%, and the limit of detection was 0.027?μg L?1. Four seawater samples obtained from the Bohai Sea were analyzed, and NFX was found only at one location at a concentration of 0.280?μg L?1. 相似文献
13.
Benito-Peña E Martins S Orellana G Moreno-Bondi MC 《Analytical and bioanalytical chemistry》2009,393(1):235-245
A novel water-compatible molecularly imprinted polymer (MIP), prepared with enrofloxacin (ENR) as the template, has been optimised
for the selective extraction of fluoroquinolone antibiotics in aqueous media. The results of a morphological characterisation
and selectivity tests of the polymer material for ENR and related derivatives are reported. High affinity for the piperazine-based
fluoroquinolones marbofloxacin, ciprofloxacin, norfloxacin and ofloxacin was observed, whereas no retention was found for
nonrelated antibiotics. Various parameters affecting the extraction efficiency of the polymer have been optimised to achieve
selective extraction of the antibiotics from real samples and to reduce nonspecific interactions. These findings resulted
in a MISPE/HPLC-FLD method allowing direct extraction of the analytes from aqueous samples with a selective wash using just
50% (v/v) organic solvent. The method showed excellent recoveries and precision when buffered urine samples fortified at five
concentration levels (25–250 ng mL−1 each) of marbofloxacin, ciprofloxacin, norfloxacin, enrofloxacin and sarafloxacin were tested (53–88%, RSD 1–10%, n = 3). Moreover, the biological matrix of the aqueous samples did not influence the preconcentration efficiency of the fluoroquinolones
on the MIP cartridges; no significant differences were observed between the recovery rates of the antibiotics in buffer and
urine samples. The detection limits of the whole process range between 1.9 and 34 ng mL–1 when 5-mL urine samples are processed. The developed method has been successfully applied to preconcentration of norfloxacin
in urine samples of a medicated patient, demonstrating the ability of the novel MIP for selective extraction of fluoroquinolones
in urine samples. 相似文献
14.
A group selective molecularly imprinted solid phase extraction (MISPE) for malachite green (MG) from fish water and fish feed samples was developed. Using MG as template molecule, methacrylic acid as functional monomer, ethylene glycoldimethacrylate as linking agent and bulk polymerization as synthetic method, the molecularly imprinted polymers (MIPs) were synthesized and characterized with rebinding experiment. The Scatchard polt's analysis revealed that the template-polymer system showed the two-site binding behavior with dissociation constants of 0.3194 μmol L−1 and 15.70 μmol L−1, respectively. MG and two structurally related compounds, leucomalachite green (LMG) and crystal violet (CV) were employed for selectivity test. The MIPs exhibited the highest selective rebinding to MG, but also displayed 83.0% and 87.5% of cross-reactivity with LMG and CV, demonstrating that MIPs could be used as group recognition sorbents in solid phase extraction. The extraction conditions of MISPE column for MG were optimized. Tap water samples spiked with MG at concentration of 0.5-10 ng mL−1 were extracted by MISPE column and analyzed by high performance liquid chromatography. The recoveries of MISPE column for MG extraction were found to be 76.8-93.7% with the relative standard deviations of 2.12-10.09%, indicating the feasibility of the prepared MIPs for MG extraction. No detectable MG was observed in one fish farming water sample and two fish feed samples; while the MG concentrations in two pet fishpond water samples were found at 1.50 ng mL−1 and 0.67 ng mL−1, respectively. 相似文献
15.
The application of novel electrosynthesized polydopamine (PDA)-imprinted film as a recognition element for the capacitive sensing of nicotine is reported. The PDA-imprinted film was electropolymerized directly on the gold electrode surface in the presence of nicotine without an additional self-assembled thiol sublayer. The compact PDA film has various functional groups that aid the imprinting procedure. Furthermore, the film shows good capacitive response since it is insulating in nature and ultrathin. The sensor’s linear response range for nicotine was between 1–25 μmol L−1, with a detection limit of 0.5 μmol L−1. The proposed molecularly imprinted polymer capacitive (MIPC) sensor exhibited good selectivity for nicotine. The reproducibility and repeatability of the MIPC senor were all found to be satisfactory. The results from sample analysis confirmed the applicability of the MIPC sensor to quantitative analysis. 相似文献
16.
Junfa Yin Zihui Meng Mingjun Du Cong Liu Maoyong Song Hailin Wang 《Journal of chromatography. A》2010,1217(33):5420-5426
To assess the potential risks associated with the environmental exposure of β-lactam antibiotics (BLAs), the monitoring of the occurrence, distribution, and fate of these emerging contaminants in the environment is required. Herein, we demonstrate a molecularly imprinted solid-phase extraction (MISPE) method for selective and reliable screening of trace BLAs in river and tap water. By developing a low-temperature photopolymerization, highly selective molecularly imprinted polymers (MIPs) for five BLAs (penicillin G, amoxicillin, ampicillin, nafcillin and mezlocillin) were synthesized. Nafcillin was chosen as a pseudo template to make the MIP sorbent (Nafc-MIP), which was used in pseudo-template MISPE for preconcentration of the other four BLAs from river and tap water. The application of pseudo-template MISPE overcomes the template bleeding, which significantly elevates the sample background and restricts the application of MIP for detection of the target BLA below 2 μg/L. The average recoveries of BLAs are in the range of 60–90% when Nafc-MIP was adopted as the selective MISPE sorbent. The developed method was validated, and applied to the screening of trace β-lactam antibiotics in river and tap water. The linearity of the calibration curve for each BLA was observed over the range of 0.1–20 μg/L (r > 0.998). The β-lactam antibiotics were found within the range of 0–9.56 μg/L in river water at the downstream of antibiotics manufacturers, and none were detected in the tap water. 相似文献
17.
de Jesus Rodrigues Santos W Lima PR Tarley CR Kubota LT 《Analytical and bioanalytical chemistry》2007,389(6):1919-1929
Despite the increasing number of applications of molecularly imprinted polymers (MIP) in analytical chemistry, the synthesis
of polymers with hemin introduced as the catalytic center to mimic the active site of peroxidase remains as a challenge. In
the current work, a new type of molecularly imprinted polymer (MIP) was synthesized with 4-aminophenol (4-APh) as the template
and two monomers: hemin, which acts as the catalytic center, and methacrylic acid (MAA), which is used to build the active
sites. This work shows that MIP successfully mimics peroxidase. For this purpose, a flow injection analysis system coupled
to an amperometric detector was investigated through multivariate analysis. The determination of 4-APh was not affected by
the equimolar presence of structurally similar phenol compounds, including catechol, 4-chloro-3-methylphenol, 2-aminophenol,
guaiachol, chloroguaiachol and 2-cresol, thus highlighting the good performance of the imprinted polymer. Under the optimized
experimental conditions, an analytical curve covering a wide linear response range from 0.8 up to 500 μmol L−1 (r > 0.999) was obtained, and the method gave satisfactory precisions (n = 8), as evaluated via the relative standard deviation (RSD), of 4.1 and 3.2% for solutions of 4-APh of 50 and 500 μmol L−1, respectively. Recoveries of 96–111% from water samples (tap water and river water) spiked with 4-APh were achieved, thus
illustrating the accuracy of the proposed system.
Figure Schematic presentation of the synthesis of the MIP 相似文献
18.
Bhim Bali Prasad Mahavir Prasad TiwariRashmi Madhuri Piyush Sindhu Sharma 《Journal of chromatography. A》2010,1217(26):4255-4266
Thyroxine is a known disease biomarker which demands a highly sensitive and selective technique to measure ultratrace level with enantiodifferentiation of its optical isomers (d- and l-), in real samples. In this work, an approach of hyphenation between molecularly imprinted micro-solid phase extraction and a complementary molecularly imprinted polymer-sensor was adopted for enantioseparation, preconcentration, and analysis of d- and l-thyroxine. In both techniques, the same imprinted polymer, coated on a vinyl functionalized self-assembled monolayer modified silver wire, was used as the respective extraction fiber as well as sensor material. This combination enabled enhanced preconcentration of test analyte substantially so as to achieve the stringent limit [limit of detection: 0.0084 ng mL−1, RSD = 0.81%, S/N = 3 (d-thyroxine); 0.0087 ng mL−1, RSD = 0.63%, S/N = 3 (l-thyroxine)] of clinical detection of thyroid-related diseases, without any problems of non-specific false-positive contribution and cross-reactivity. 相似文献
19.
The highly selective, fast and effective sample pretreatment technique molecularly imprinted solid-phase extraction (MISPE) can overcome the low sensitivity of the highly efficient capillary electrophoresis-UV method (CE-UV). In this work, narrowly dispersible bisphenol A (BPA)-imprinted polymeric microspheres with a high capacity factor of k′ = 6.8 and an imprinted factor of I = 6.53 were investigated as selective solid-phase extraction (SPE) sorbents for use in extraction of BPA from different sample matrices (tap water, wastewater, Yangtze River water, soil from the Yangtze River, shrimp and human urine). Washing and eluting protocols of MISPE were optimized. Under optimal conditions, recoveries of MISPE were investigated. Recoveries were basically constant and the relative standard deviation (RSD) was lower than 5.8% when loading volumes changed from 1 to 50 mL. Recoveries ranged from 71.20% to 86.23% for different sample matrices. Compared with C18 SPE, MISPE had higher selectivity and recovery for BPA. BPA was determined with good accuracy and precision in different complex samples using CE-UV coupled with MISPE. Spiked recoveries ranged from 95.20% to 105.40%, and the RSD was less than 7.2%. Because a large loading volume was achieved, the enrichment efficiency of pretreatment and the sensitivity of this method were improved. The limits of detection of this MISPE-CE-UV method for BPA in tap water, wastewater, Yangtze River water, soil from the Yangtze River, shrimp and human urine were 3.0 μg L− 1, 5.4 μg L− 1, 6.9 μg L− 1, 2.1 μg L− 1, 1.8 μg L− 1 and 84 μg L− 1, respectively. 相似文献
20.
Leveriza F. Arenas Benilda S. Ebarvia Fortunato B. Sevilla III 《Analytical and bioanalytical chemistry》2010,397(7):3155-3158
A piezoelectric quartz crystal (PQC) sensor based on a molecularly imprinted polymer (MIP) has been developed for enantioselective
and quantitative analysis of d-(+)-methamphetamine (d(+)-MA). The sensor was produced by bulk polymerization and the resulting MIP was then coated on the
gold electrode of an AT-cut quartz crystal. Conditions such as volume of polymer coating, curing time, type of PQC, baseline
solvent, pH, and buffer type were found to affect the sensor response and were therefore optimized. The PQC-MIP gave a stable
response to different concentrations of d(+)-MA standard solutions (response time = 10 to 100 s) with good repeatability (RSD = 0.03
to 3.09%; n = 3), good reproducibility (RSD = 3.55%; n = 5), and good reversibility (RSD = 0.36%; n = 3). The linear range of the sensor covered five orders of magnitude of analyte concentration, ranging from 10−5 to 10−1 μg mL−1, and the limit of detection was calculated as 11.9 pg d(+)-MA mL−1
. The sensor had a highly enantioselective response to d(+)-MA compared with its response to l(−)-MA, racemic MA, and phentermine.
The developed sensor was validated by applying it to human urine samples from drug-free individuals spiked with standard d(+)-MA
and from a confirmed MA user. Use of the standard addition method (SAM) and samples spiked with d(+)-MA at levels ranging
from 1 × 10−3 to 1 × 10−2 μg mL−1 showed recovery was good (95.3 to 110.9%). 相似文献