Conventional High-performance Liquid Chromatography Research Articles

Exploring a reversible adaptation of conventional HPLC for capillary-scale operation

This study introduces a feasible approach for utilizing a conventional High-Performance Liquid Chromatography (HPLC) instrument at the capillary scale (1 - 10 µL/min). The development of an active flow splitter and an adapted UV-visible (UV–vis) detection cell are described. The system employs an Arduino Uno board to monitor a flow sensor and control a stepper motor that automates a split valve to achieve capillary-scale flow rates from a conventional pump. A capillary UV–vis cell compatible with conventional detectors, featuring an optical path length with a volume of 14 nL, was developed to address the detection challenges at this scale and minimize extra column band broadening. The system performance was assessed by a lab-packed LC capillary column with 0.25 mm x 15 cm dimensions packed with 3.0 µm C18 particles. Model compounds, particularly polycyclic aromatic hydrocarbons (PAHs), were employed to assess the functionality of all developed components in terms of theoretical plates, resolution, and band broadening. The proposed system is a profitable, reliable, and cost-effective tool for miniaturized liquid chromatography.

Validation of An Efficient 2D-HPLC Method for The Determination of Pentazocine

Pentazocine is an opioid analgesic used to treat moderate to severe pains. The real analysis for the pharmaceutical products containing pentazocine is basically to ensure the correct dose and patient safety. This study developed and validated an improved high-performance liquid chromatography (HPLC) method in the selective and accurate quantification of pentazocine. Two-dimensional (2D) HPLC technique is employed to enhance the resolution and selectivity compared to conventional HPLC methods. The 2D-HPLC instrumentation consists of two C18 columns coupling with a switching valve to capture fractions from the first column, which is analyzed in the second column. The mobile phase was optimized to 45% acetonitrile and 55% water with 0.1% phosphoric acid. The method was validated in the International Conference on Harmonization guidelines and shows excellent linearity (R2=0.998), limit of detection of 1.58 μg/L, accuracy of 97.70–102.50%, and precision by relative standard deviation (RSD) of 1.02–4.20%. Selectivity was verified in resolving pentazocine from paracetamol, caffeine, ibuprofen, and oxycodone in laboratory mixtures. The utility of the 2D-HPLC method was demonstrated by accurate quantification of pentazocine in pharmaceutical injections and tablets unaffected in excipients. This research provides a rich validating technique to enhance the quality control testing of pharmaceuticals containing pentazocine.

Use of Commercial Mixed-Mode Stationary Phases and Sorbents in the High-Performance Liquid Chromatography Analysis and Solid-Phase Extraction of Ionized and Hydrophilic Bioactive Compounds.

Mixed-mode high-performance liquid chromatography (HPLC) is increasingly used for the analysis of ionic and highly hydrophilic drugs, which are difficult to separate by conventional single-mode HPLC. In the former case, chromatographic separation is achieved using one of the several commercially available mixed-mode stationary phases, typically combinations of reversed and ion-exchange phases. Moreover, mixed-mode stationary phases can be used as solid-phase extraction (SPE) sorbents. This review focuses on the recent applications of mixed-mode stationary phases in the chromatographic analysis of bioactive compounds, such as drugs, herbicides, and pesticides. Specifically, we briefly summarize HPLC methods utilizing mixed-mode stationary phases and SPE pretreatment procedures utilizing mixed-mode sorbents developed in the last decade, thus providing a reference work for overcoming the difficulties in analyzing ionized or hydrophilic drugs by conventional reversed-phase chromatography.

Comparison of Glycated Hemoglobin (HbA1c) Values Estimated by High-Performance Liquid Chromatography and Spectrophotometry: A Pilot Study.

Background Invasive blood sample collection followed by high-performance liquid chromatography (HPLC) based analysis is the gold standard for estimating glycated hemoglobin level or HbA1c currently. Spectrophotometry could be an alternative that holds the potential to be translated into a portable, non-invasive device for glycated hemoglobin level estimation. This study compares HbA1c values obtained from HPLC and spectrophotometry. Methods Venous blood samples were collected from both diabetic and non-diabetic participants in a cross-sectional study. The samples were subjected to both HPLC and spectrophotometry-based estimation of HbA1c%. The results obtained were compared, and the relationship between the two estimations were assessed. Results About 15 diabetic and non-diabetic individuals participated in the study and 28 samples were included in the final analysis. The Pearson's correlation coefficient was 0.65 (95% CI, 0.37-0.82), indicating that there was a strong positive association. This was further supported by the findings from linear regression analysis with a p-value of <0.001. Conclusions The positive correlation between the HPLC and spectrophotometric values supports the hypothesis that spectrophotometry could be an alternative to conventional HPLC for the measurement of HbA1c. This needs to be further validated through larger, well-powered studies.

A simple and green ion-pairing extraction colorimetric determination of chlorhexidine employing coconut oil as a natural solvent with image processing

A cost-effective, simple, and green determination of chlorhexidine is proposed. A commonly available bromothymol blue serves as a reagent. The ion-pairing of chlorhexidine and bromothymol blue in an aqueous solution can be extracted into an organic phase of coconut oil, which is proposed as an alternative natural green solvent, replacing the conventional toxic organic solvents. An investigation of the chlorhexidine-bromothymol blue ion pair was made spectrophotometrically and via image processing using a smartphone camera. Downscaling is operated for the extraction of 500 μL of an aqueous mixture containing chlorhexidine and bromothymol blue in phosphate buffer (pH 7.5, 5 mmol/L) with 500 μL of coconut oil for 3 min by hand-shaking. A set of 12 extraction tubes can be operated in one run. After phase separation by centrifuging (3000 rpm, 3 min), the 12 tubes are photographed in one shot using a smartphone. Images of both aqueous and organic phases are evaluated for red-green-blue (RGB) color intensity system. Linearity equations: R intensity = 1.205 [Chlorhexidine] – 23.6 (r2: 0.9795), and ΔB intensity = 1.525 [Chlorhexidine] – 36.75 (r2: 0.9907), are obtained for aqueous and organic phases, respectively. The limits of detection (LOD) and quantitation (LOQ) were 12 and 40 mg/L for aqueous, while 11 and 34 mg/L for organic phases, respectively. The proposed procedure was applied to real samples of active pharmaceutical ingredients (API), disinfectant cleaner, and mouthwash. The results obtained by the proposed procedure agree with the high-performance liquid chromatography (HPLC) reference method that utilizes a UV detector. In evaluations using the green analytical procedure index (GAPI) and analytical greenness (AGREE), the proposed procedure was found to be the greenest compared to the conventional spectrophotometric method and HPLC. The proposed procedure involved the UN-SDGs #3, #4, and #12 and scored the highest value of the need, quality, and sustainability (NQS) index. The proposed procedure encourages sustainable chemistry and pharmacy.

Simultaneously characterization of multiple constituents in Valeriana jatamansi Jones using an online supercritical fluid extraction-high-performance liquid chromatography/supercritical fluid chromatography-mass spectrometry system.

Valeriana jatamansi Jones is a commonly used traditional Chinese medicine, boasting rich effective compositions with versatile chemical structures and wide polarity, including iridoids, chlorogenic acid, and flavonoids. Previous reports indicate that conventional high-performance liquid chromatography (HPLC) analytical methods have proven inefficient performance in comprehensively characterizing components in Valeriana jatamansi. In the present study, a hybrid online analytical platform combining supercritical fluid extraction with both conventional HPLC separation (reverse phase) and supercritical fluid chromatography (normal phase) has been established and validated. This system can provide online extraction with two different chromatographic separation modes to increase separation ability and has been connected to a mass spectrometer to acquire high-resolution mass spectrometry data. Then, the online platform was applied to screening components in Valeriana jatamansi. A total of 117 compounds were identified, including five lignans, 18 organic acids, six flavonoids, and 88 iridoids. Thirty-three compounds were reported from Valeriana jatamansi for the first time. These results enrich our understanding of the components of Valeriana jatamansi and prove that the developed online platform in this study is a robust approach for accelerating working efficiency in comprehensively analyzing complicated samples.

Development of simple purification method for oligonucleotides synthesized using phosphoramidite for 5′-end modification as capping reagent

Oligonucleotide therapeutics are generally prepared via solid-phase synthesis, and many impurities derived from the synthesis process are present in crude oligonucleotides. Among the various impurities typical of oligonucleotide synthesis, shortmers, which lack a few residues from the desired oligonucleotide therapeutics, are difficult to remove using conventional high-performance liquid chromatography (HPLC) purification because they have similar structures and physical properties to the desired oligonucleotide. In this study, we developed a simple purification method for oligonucleotide therapeutics. In our strategy, the retention of shortmers on the reversed-phase HPLC column was increased by using a highly lipophilic phosphoramidite, which is a reagent for 5′-end modification of oligonucleotides, instead of acetic anhydride during solid-phase synthesis, and only the target oligonucleotide could be eluted from a reversed-phase HPLC pretreatment column.

Fe-MOF-based fluorescent sensor with on/off capabilities for the highly sensitive detection of tert-butylhydroquinone in edible oils

In this work, a “turn off-on” fluorescent sensor was developed for highly sensitive determination of tert-butylhydroquinone (TBHQ) based on an Fe(III)-based metal-organic framework (Fe-MOF). An Fe-MOF with an octahedral structure was synthesized via a simple hydrothermal method using ferric chloride hexahydrate and 2-aminoterephthalic acid (NH2-BDC) as raw materials. The fluorescence of Fe-MOF is extremely weak owing to ligand-to-metal charge transfer (LMCT) and internal filtration effect (IFE). When the system contained TBHQ, the binding of TBHQ to Fe(III) inhibited the LMCT of the fluorescent ligand NH2-BDC to Fe(III), releasing the fluorescence of NH2-BDC and thus restoring the fluorescence. With this as the basis, a rapid, sensitive, and selective fluorescence sensor is developed for the detection of TBHQ. Under the optimal conditions, TBHQ showed good linearity with fluorescence intensity in the range of 0–1.5 × 102 μmol L−1 and a detection limit of 0.0030 μmol L−1 (S/N = 3). The selectivity, reproducibility, and stability of the developed Fe-MOF-based sensors are comprehensively studied. Finally, the practicality of the method is verified by examining the detection of TBHQ in soybean oil; the results are consistent with those obtained using conventional high-performance liquid chromatography.

Assessing the Comparative Efficacy of Multiple Whole-blood Count-based Testing Strategies for Thalassaemia Diagnosis

Context: Complete blood count (CBC) with confirmatory high-performance liquid chromatography (HPLC) is the gold standard for thalassemia screening. Because of the constraints of a high-pressure liquid chromatography facility, they develop alternative approaches to screening when the population to be screened is large. Aims: The objective of this meta-analysis is to evaluate the diagnostic accuracy of alternative approaches to thalassemia screening. This study is important, as accurate and accessible thalassemia screening can improve the quality of life for patients and reduce the burden on health-care systems. Settings and Design: The systematic review and meta-analysis followed the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. Subjects and Methods: The present systematic review comprises 74,284 thalassemia-positive patients, identified using CBC and conventional HPLC methods was published between 2012 and 2022. After further screening, 23 studies were included in the present study. Statistical Analysis Used: The Moses-Littenberg Summary Receiver Operating Characteristic (SROC) model, the bivariate model, and the SROC reporting model are the examples of models that also consider sensitivity and specificity. Results: The total diagnostic odds ratio was 88.981 (95% confidence interval 37.645–210.321). Subgroup analysis was determined by a mixed-effects model, with I 2 (residual heterogeneity/unaccounted variability) at 90% and Partial Area under ROC curve (restricted to observed False Positive Rates and normalized) was 0.951. Conclusions: This systematic review investigated the efficacy of using CBC parameters to distinguish between iron deficiency anemia and the thalassemia trait. This can help reduce health-care costs and improve the accuracy of the results.

Application of magnetic solid-phase extraction for sensitive determination of anticancer drugs in urine by means of diamino benzidine tetrachlorohydrate modified magnetic nanoparticles.

The analysis of drug active molecules and residues in the treatment of cancer is important for the sustainability of human life and therapeutic effects. For this purpose, a new magnetic sorbent was developed to use in solid phase extraction prior to conventional high-performance liquid chromatography (HPLC) analysis of Paclitaxel (PAC) and Gemcitabine (GEM) molecules. In this study, a separation and pre-concentration approach based on magnetic solid phase extraction (MSPE) was proposed for PAC and GEM by means of using a newly synthesized magnetic sorbent. After the MSPE procedure, an HPLC system with a diode array detector (DAD) was used to analyze trace amounts of PAC and GEM anticarcinogenic drugs in urine samples. Surface modification of magnetic Fe3O4 nanoparticles was carried out by diaminobenzidinetetrachloro hydrate (DABTC) for the first time and a useful sorbent was obtained for MSPE experiments. In the proposed method, PAC and GEM molecules were retained on the c in the presence of a pH 5.0 medium and desorbed to 300 μL of acetonitrile: methyl alcohol (1:1) eluent phase before HPLC-DAD analysis. Under the optimized conditions, the limit of detection (LOD) values for PAC and GEM were 1.38 and 1.44ngmL-1 while the enhancement factor for PAC and GEM were 139.5 and 145.3, respectively. The relative standard deviations (RSD %) for PAC and GEM were below 3.50% in inter-day repeated experiments by means of model solutions containing 100ngmL-1 drug active ingredients. Synthesis and characterization of DABTC-Fe3O4 nanoparticles were performed using suitable methodologies. Optimization of MSPE was done step by step. And finally, the developed method was successfully applied to urine samples with quantitative recoveries in the range of 99.0% and 105.0%.

Electrochemical platform based on activated carbon/graphene oxide-gold nanoparticle composites for the electrochemical sensing of methylparaben in cosmetic samples

We report on a simple and highly sensitive square wave voltammetric method for the determination of methylparaben (MP) using a pencil graphite electrode (PGE) modified with gold nanoparticles and activated carbon/graphene oxide (denoted as AuNP@AC/PGE and AuNP@GO/PGE). The modified electrodes display enhanced electroactivity and antifouling for the oxidation of MP compared to the unmodified PGE. Under optimized conditions, both types of the modified electrode exhibit similar efficiency in terms of the linear response to MP in the concentration range between 0.030 and 1.0 mM, high reproducibility (RSD of 3.44–3.51%), and repeatability (RSD of 2.79–3.36%). However, the AuNP@GO/PGE (2.02 μM) provided a better limit of detection than the AuNP@AC/PGE (2.17 μM). In addition, the modified electrodes also have a remarkably stable response, and up to 30–40 analyses are possible at 0.2 mM of MP. Additionally, the sensors provided acceptable recoveries ranging from 85 to 110% for the samples spiked with MP from four types of cosmetics. In addition, the results agreed with those obtained from conventional high performance liquid chromatography coupled with diode array detection.

Analysis of canthin-6-one alkaloids derived from Eurycoma spp. by micellar liquid chromatography and conventional high-performance liquid chromatography: a comparative evaluation.

Extracts of Eurycoma longifolia Jack (EL) and Eurycoma harmandiana Pierre (EH) contain numerous bioactive compounds and varying matrices that are challenging to separate using chromatographic techniques. Herein, micellar liquid chromatography (MLC) was used to analyze canthin-6-one alkaloids contained in these extracts, and the achieved performance was compared with that of a conventional high-performance liquid chromatography (HPLC) method. The optimal mobile phase of MLC corresponded to 15 : 85 (v/v) acetonitrile : water (pH 3) containing 110 mM sodium dodecyl sulfate and 10 mM NaH2PO4. The retention times of canthin-6-one-9-O-β-d-glucopyranoside, 9-hydroxycanthin-6-one, canthin-6-one, and 9-methoxycanthin-6-one were 4.78/15.42, 17.64/24.11, 32.84/38.27, and 39.04/39.86 min, respectively, in the cases of isocratic MLC and conventional HPLC. In both cases, the analyte resolution exceeded 1.5. The MLC elution behavior of the examined analytes was largely determined by their hydrophobicity and ionization. The sensitivity, precision, accuracy, and per-run acetonitrile consumption of the MLC method were comparable to those of the conventional HPLC method. However, the latter method exhibited higher performance for application to EL and EH samples, particularly those with low analyte concentrations and varying sample matrices. Overall, the analysis of canthin-6-one alkaloids using MLC was limited to trace analytes due to interference by the matrix.

Ultra-Performance Liquid Chromatography - An Updated Review

Ultra-performance liquid chromatography (UPLC) has an advantage over conventional High-performance liquid chromatography (HPLC) as UPLC offers substantial resolution, speed, and sensitivity during analysis. This advanced chromatographic technique uses sub-2μm particles for the stationary phase. As a result, it saves time and reduces solvent consumption, which allows it to take less run time and makes it highly efficient.

A Simple Potentiometric Biosensor based on Carboxylesterase for the Analysis of Aspartame

A potentiometric aspartame biosensor was fabricated by simply depositing the carboxylesterase (CES)-bonded poly(n-butyl acrylate-n-acryloxysuccimide) [CES-poly(nBA-NAS)] microspheres on a Ag/AgCl screen-printed pH selective electrode. The pH transducer was made from non-plasticized polyacrylate membrane containing a hydrogen ionophore and lipophilic salt. The immobilized CES enzyme catalyzed the enzymatic hydrolysis of aspartame to L-aspartic acid (L-Asp), L-phenylalanine and methanol. Potentiometric determination of aspartame concentration was performed by quantifying the hydrogen ion concentration produced from L-Asp. The potentiometric determination of aspartame exhibited good selectivity with near Nernstian response. The sensitivity of the biosensor was closed to the Nernstian value, i.e., 50-52 mV decade-1 with a dynamic linear response range from 10-5 to 10-2 M and detection limit approaching 10-6 M. The aspartame biosensor demonstrated good repeatability and reproducibility with relative standard deviation (RSD) of 1.9% and 1.6%, respectively (n=3). The potentiometric aspartame biosensor was demonstrated to be reliable for determining aspartame content in sweetener samples and was comparable to the conventional high-performance liquid chromatography (HPLC) method for aspartame analysis.

Development and validation of a rapid resolution liquid chromatographic (RRLC) method for the determination of Atomoxetine HCl in its pharmaceutical dosage form

The present work described the development of a rapid resolution liquid chromatographic (RRLC) method for atomoxetine in its pharmaceutical dosage form Strattera ®. The analysis was achieved on Agilent Eclipse XDB C18 column (50 mm x 4.6 mm i.d, 1.8 mm particle size) using mixture of aqueous 0.04 M Glacial acetic acid and 0.03M triethylamine (TEA), pH 4.6 - Acetonitril (42 : 58, v/v) as mobile phase at flow rate of 0.27 ml/min and UV detection at 220 nm. The developed method was linear over the concentration range of 4-40 mg /ml (r = 0.99969) with a limit of detection and quantitation 0.44 mg /ml and 1.32 mg /ml for atomoxetine. The developed RRLC method was validated with respect to specificity, linearity, accuracy, and precision, limit of detection and limit of quantitation. The statistical analysis proved that the developed method for quantification of atomoxetine as bulk drug and from pharmaceutical preparation is reproducible and selective. The proposed RRLC method can be used fo the quality control of formulated products containing atomoxetine. Rapid resolution liquid chromatography RRLC has become an increasingly useful approach to achieve higher throughput, improve sensitivity and reduce costs. The agilent 1200 rapid resolution LC system enables faster analysis (theoretically up to 20x) than with conventional high performance liquid chromatography (HPLC) while maintaining equivalent resolution. This is achieved by using sub-2 micron column particle chemistry.

Development and Validation of new UPLC Method for the Simultaneous estimation of Darunavir, Dolutegravir and Ritonavir in Combined Tablet Dosage form

A rapid, simple, sensitive and selective analytical method was developed by using reverse phase Ultra performance liquid chromatographic technique for the simultaneous estimation of darunavir, dolutegravir and ritonavir in combined tablet dosage form. The developed method is superior in technology to conventional high performance liquid chromatography with respect to speed, resolution, solvent consumption, time, and cost of analysis. Elution time for the separation was 3 min and ultra violet detection was carried out at 225 nm. Efficient separation was achieved on BEH C18 (50 x 2.1mm, 1.7 ) UPLC column using phosphate buffer and acetonitrile as organic solvent in a linear isocratic program. Resolution between darunavir, dolutegravir and ritonavir was found to be more than 3.5. The active pharmaceutical ingredient was extracted from tablet dosage from using a mixture of water and acetonitrile used as diluent. The calibration graphs were linear for darunavir, dolutegravir and ritonavir in the range of 100-600 g/ml, 12.5-75 g/ml and 6.25-37.5 g/ml respectively. The mean percentage recoveries for darunavir, dolutegravir and ritonavir were found to be in the range of 99.13 and 99.59 and 99.72 % respectively. Developed UPLC method was validated as per International Conference on Harmonization specifications for method validation. This method can be successfully employed for simultaneous estimation of darunavir, dolutegravir and ritonavir in bulk drugs and formulations.

Development of a rapid dot-blot assay for ochratoxin A (OTA) detection using peptide conjugated gold nanoparticles for bio-recognition and detection

Ochratoxin A is a secondary metabolite produced by fungi and a major mycotoxin contaminating cereal grains and cereal-based products. Although, ochratoxin A is hepatotoxic, nephrotoxic and carcinogenic, its detection is limited due to low awareness, time-consuming conventional methods and false positive results. In this study, a rapid, user-friendly dot-blot assay was developed using peptide conjugated gold nanoparticles (AuNPs) as a detection agent. The peptide binding to ochratoxin A was evaluated by the apparent dissociation constant ( K d app ) measurement using indirect enzyme linked immunoabsorbent assay. A low K d value (1.046 μM) suggested high binding of peptide with ochratoxin A. The potential of peptide-based ochratoxin A recognition was translated to a portable platform using streptavidin functionalized AuNPs conjugated to a biotinylated 11-mer peptide. Dot-blot assay was developed for detection of ochratoxin A with a limit of detection of 0.49 μg/kg. Negligible cross-reactivity with low spot intensities were observed for high concentrations of other mycotoxins like aflatoxin B1 and citrinin, in comparison to control. Further, percent recovery of ochratoxin A from spiked wheat samples by dot-blot was comparable to the conventional high performance liquid chromatography (HPLC). Moreover, detection of ochratoxin A by dot-blot was validated by HPLC in 65 whole wheat, crushed wheat coarse, crushed wheat fine and wheat flour samples with a high correlation with R 2 = 0.93. HPLC and dot-blot confirmed the presence of ochratoxin A ˂ 5 μg/kg in the samples. Therefore, a portable, easy-to-use dot-blot assay for ochratoxin A detection with potential of application at each stage of harvesting, storage, production and distribution can contribute to safe and healthy food and feed. • A rapid, on-site, sensitive visual Dot-blot assay was developed for ochratoxin detection. • Peptide conjugated gold nanoparticles were employed as a recognition label to replace expensive antibodies. • The developed Dot-blot assay had a limit of detection of 0.49 μg/kg for ochratoxin. • High sensitivity and specificity for ochratoxin detection.

Front Cover: Online monitoring of small volume reactions using compact liquid chromatography instrumentation

DOI: 10.1002/sscp.202200012 The cover picture represents the translation of repetitive reaction mixture analysis outside a fume hood using a conventional high performance liquid chromatography stack with manual syringe sampling to online analysis inside a fume hood using a simple, compact, hand-portable capillary liquid chromatograph that can be easily placed very close to the reaction vessel. The extremely small sample volume required for analysis by capillary liquid chromatography allows the use of miniature reaction vessels with minimal disturbance of the reaction mixture.

Separation and detection of D-/L-serine by conventional HPLC

D-serine has a role as an endogenous allosteric agonist of N-methyl-D-aspartate (NMDA) receptor in the mammalian brain. In this study, we present a detailed description of our method that measures D-/L-serine by using conventional high performance liquid chromatography (HPLC).• We reacted D-serine and L-serine with ortho-phthalaldehyde (OPA) and N-acetyl-L-cysteine (NAC) to form diastereomeric isoindole derivatives, then we separated and detected them by conventional reversed phase HPLC with electrochemical detector (ECD).• We present typical measurement data of rat brain homogenate as an example of a convenient, appropriate method for measuring brain concentrations of D-serine.• Since many peaks appear in biological samples, we confirmed that the peaks were derived from serine by treating the sample with D-amino oxidase and catalase to decompose D-serine. As a results, one peak disappeared, suggesting that it is derived from D-serine.

Preparation of molecularly imprinted polymers based on covalent organic frameworks and their application to selective recognition of trace norfloxacin in milk

诺氟沙星(NFX)作为一种常见的喹诺酮类兽药,被广泛应用于畜牧业中,但其会残留在动物体内,进而对人体健康造成危害,为此有许多国家和组织均对NFX残留量进行了严格限制。为实现对复杂体系中痕量NFX残留的准确与可靠分析,该文制备了一种以共价有机框架(COFs)为载体的分子印迹聚合物(MIPs)。首先,在室温条件下,以金属三氟酸盐为催化剂,对苯二甲醛和3,3'-二氨基联苯为原料快速合成了“席夫碱”型共价有机框架(DP-COF)。然后将NFX、甲基丙烯酸、乙二醇二甲基丙烯酸酯与DP-COF混合,利用偶氮二异丁腈引发聚合反应,即可得到DP-COF@MIPs。整个制备过程条件温和,耗时仅5 h。采用场发射扫描电镜、傅里叶红外光谱、X射线衍射仪、BET比表面积测试仪等对其进行了表征。结果证实成功制备出了DP-COF@MIPs,该材料表面粗糙,拥有介孔范围的孔径(17.79 nm)。通过吸附实验、重复使用性实验对材料性能进行评估,结果表明该材料表观吸附容量高达41.57 mg/g,对NFX具有良好的特异性和选择性识别能力,且重复使用率令人满意。结合HPLC-UV-Vis,实现对牛奶样品中痕量NFX的检测。在3个加标水平下(0.03、0.1、0.3 mg/L),平均回收率为88.8%~92.9%,相对标准偏差小于1.7%。结果表明,该方法可以实现在复杂基质中对兽药残留高选择性、高灵敏度及准确性的检测。