Temperature-dependent decomposition of the CL-20/MTNP cocrystal after phase separation.

CL-20 (2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane)-based cocrystals are attractive energetic cocrystals with a potential for high energy and low sensitivity, which account for nearly one-third of energetic cocrystals. The applications of cocrystal explosives require in-depth understanding of their thermal kinetics behaviors. Although thermal kinetics of the decomposition of CL-20-based cocrystals having no melting point have been studied, relevant research of CL-20-based cocrystals having a melting point, which are also the most frequently observed type, is still rare. In this study, the CL-20/MTNP (1-methyl-3,4,5-trinitropyrazole) cocrystal was chosen as a typical CL-20-based cocrystal having a melting point to investigate its thermal kinetics behavior. The thermal decomposition of CL-20/MTNP was identified to be a typical heterogeneous reaction with phase separation before decomposition. Due to the presence of intermolecular hydrogen bonds between CL-20 and molten MTNP after phase separation, the thermal decomposition behavior of CL-20/MTNP was strongly temperature-dependent. The complex decomposition reaction was separated into its three constituent pathways to simplify the kinetic analysis. On the basis of in-depth understanding of the decomposition process, the best functions of mechanism and kinetic parameters for each process of CL-20/MTNP decomposition were obtained using the model-fitting method. Finally, important thermal safety indicators, such as TMRad and SADT were simulated by combining the established kinetic models. This study provides further insights into the entire reaction process of the CL-20/MTNP cocrystal and would help in its better applications.

"Thermal escape" of MTNP: the phase separation of CL-20/MTNP cocrystals under long-term heating.

High-energy, low-sensitivity energetic cocrystals are one successful application of the supramolecular strategy. The practical application of cocrystal explosives requires an in-depth understanding of the stability of their crystal phase structure under long-term heating, but relevant research is rare. In this study, the CL-20/MTNP (2, 4, 6, 8, 10, 12-hexanitrohexaazaisowurtzitane/1-methyl-3,4,5-trinitropyrazole) cocrystal was selected as a representative cocrystal explosive to investigate its crystal phase structure stability under long-term heating. The phase separation of the CL-20/MTNP cocrystal was observed for the first time. It was revealed that the MTNP molecules at crystal defects first underwent molecular rotation, which weakened interactions between CL-20 and MTNP molecules. Then, the MTNP molecules diffused along channels surrounded by CL-20 molecules to the crystal surface and escaped to generate γ-CL-20. We call this process the "thermal escape" of MTNP, whose effect on the safety performance of the CL-20/MTNP cocrystal was studied by comparing the mechanical sensitivity of samples with different degrees of thermal escape. The mechanical sensitivity of the CL-20/MTNP cocrystal did not greatly change during the induction period, but it increased upon the loss of MTNP. Moreover, the thermal escape kinetics for the two stages were obtained to prevent or control their thermal escape. The prediction of the kinetics confirmed the validity of the kinetic analysis. This study promotes the performance evaluation and application of CL-20/MTNP cocrystals and also provides a new perspective in the investigation of cocrystal explosives.

Kinetics and mechanism of decomposition induced by solvent evolution in ICM-101 solvates: solvent-evolution-induced low-temperature decomposition.

[2,2'-Bi(1,3,4-oxadiazole)]-5,5'-dinitramide (ICM-101), a high-energy-density material, was reported in recent years. ICM-101 is the first energetic material with the 2,2'-bi(1,3,4-oxadiazole) structure as the main ring structure. The molecular structure of ICM-101 shows excellent planar characteristics, providing a new option for the design of high-energy-density materials. However, during crystal preparation, ICM-101 easily interacts with solvents and forms the corresponding solvates. Interestingly, during thermal decomposition, when the solvent escapes from ICM-101 solvates, it induces the decomposition of ICM-101. In this study, the decomposition of ICM-101 induced by solvent evolution was evaluated in detail, and the decomposition kinetic equation was established. The mechanism of solvent-evolution-induced decomposition in ICM-101 solvates was further studied, and it was found that solvent evolution might produce defects in the crystals of ICM-101 solvates, and induce the decomposition of ICM-101 on the defects.

A mechanism for two-step thermal decomposition of 2,6-diamino-3,5-dinitropyrazine-1-oxide (LLM-105).

2,6-Diamino-3,5-dinitropyrazine-1-oxide (LLM-105) is a representative of the new generation of low-sensitivity energetic materials and has been applied extensively in formulations as an insensitive high-energetic ingredient. Although the initial thermal decomposition mechanism of LLM-105 has been studied based on quantum chemical calculations, the internal mechanism of the two-step thermal decomposition still lacks experimental research. Thus, this study involves a detailed experimental study to reveal the mechanism of the two-step thermal decomposition of LLM-105. The results showed that LLM-105 decay was a consecutive reaction. The first-step reaction dominated the early stage of the LLM-105 decomposition, and its products participated in the reaction of the second step. The cleavage of NO2 and NH2 groups of LLM-105 mainly occurred in the first step, while gaseous products NO and C2N2 were released during the second reaction step. The first-step reaction had a higher oxygen consumption rate and a lower carbon consumption rate, producing more heat due to more extensive oxidation of the carbon backbone. The difference in the oxidative ability and reaction rate between the two steps resulted in a two-step exothermic and mass loss behavior. This study provides further insights into the entire reaction process of LLM-105 and would be helpful for its better application and for the design of new explosives.

Comparative Study of the Decomposition Mechanism and Kinetics of Biimidazole-Based Energetic Explosives.

It is well known that imidazoles, possessing two or more nitro substituents, are potential candidates for highly energetic explosives with detonation parameters comparable to those of 1,3,5-trinitro-1,3,5-triazacyclohexane (RDX) and 1,3,5,7-tetranitro-1,3,5,7-tetraazacyclooctane. 4,4',5,5'-Tetranitro-2,2'-bi-imidazole (TNBI) is a typical imidazole explosive with energy equivalent to that of RDX but suffers from low sensitivity (impact sensitivity 7 J). 1,1'-Diamino-4,4',5,5'-tetranitro-2,2'-biimidazole (DATNBI), a derivative of TNBI, possesses two -NH2 groups and has a higher detonation velocity (9063 m s-1) and lower impact sensitivity of 15 J, which indicates great potential for future applications. Examination of the thermal decomposition mechanism and kinetics of TNBI and DATNBI gives a more comprehensive view of the influence that the -NH2 group has on the sensitivity and storage safety of the energetic explosive-based TNBI molecular skeleton. Herein, the thermal decomposition mechanism is studied, showing that detachment of -NH2 groups from DATNBI generates 1-diamino-4,4',5,5'-tetranitro-2,2'-biimidazole (ATNBI) and TNBI and induces self-decomposition. Although the decomposition peak temperature of DATNBI is significantly lower than that of TNBI at the same heating rate; its self-accelerating decomposition temperature (50 kg) is only 4 K lower. Therefore, the -NH2 group displays good ability of reducing sensitivity but has no influence on storage safety of DATNBI.

The effects of H+, NH3OH+ and NH4+ on the thermal decomposition of bistetrazole N-oxide anion.

The bistetrazole N-oxide energetic ionic salt dihydroxylammonium 5,5'-bistetrazole-1,1'-diolate (TKX-50) has attracted great interest as it breaks through the limitations of the traditional nitro group, high detonation velocity and moderate impact sensitivity. Reports show that TKX-50 transforms into the 5,5'-bis(2-hydroxytetrazole) (BTO) precursor, which is further decomposed and partly converted to diamino 5,5'-bistetrazole-1,1'-diolate (ABTOX). Studying the effects of H+, NH3OH+ and NH4+ on the thermal decomposition mechanism of bistetrazole N-oxide anion would provide a more comprehensive understanding of the TKX-50 decomposition mechanism. Herein, TKX-50, BTO and ABTOX decomposition rates, on-line analysis of the gas products, as well as quantitative analysis, are presented. It was found that the presence of two H+ decreases the decomposition temperature, whereas NH3OH+ greatly increases the decomposition rate. In the presence of NH3OH+, the bistetrazole N-oxide anion completely decomposes without producing C2N2; however, NH4+ promotes the polymerization of C2N2 generated by the bistetrazole N-oxide anion, and the amount of NO produced is greater than that of N2O. Therefore, in the TKX-50 decomposition process, the bistetrazole N-oxide anion does not receive two H+ simultaneously and converts into BTO. Furthermore, the competition between cations and their decomposition products for the H+ affects the degree of decomposition, which is important in understanding the energy release mechanism.

A study on the comprehension of differences in specific kinetic energy of TKX-50 and HMX from the perspective of gas products.

5,5'-Bitetrazole-1,1'-dioxydihydroxylamine salt (TKX-50), a high-energy energetic material, possesses good safety and energy properties. The energy characteristic data of TKX-50 are commonly generated via theoretical simulation and experimental measurements. Interestingly, the detonation velocity of TKX-50 is higher than HMX, but the specific kinetic energy of TKX-50 is the opposite. Thus, a systematic study on the decomposition mechanism of TKX-50 is important to establish the reasons for this variation in specific kinetic energy. Although the thermal decomposition mechanism of TKX-50 has been reported, the specific compositional changes of its gas products under different heating conditions remain unknown, hindering a comprehensive understanding of the mechanism from the perspective of gas products. Herein, the gas products of TKX-50 and HMX in thermal decomposition and thermal explosion are investigated and compared. It was found that more TKX-50 is converted to ABTOX for further decomposition when the heating rate increases. ABTOX can decompose to C2N2, which is prone to polymerization, generating a solid residue under high temperature and pressure. Although polymerized C2N2 decomposes and burns during the explosion, it delays the time of TKX-50 reaching its maximum amount of outgassing, thereby affecting its specific kinetic energy. Furthermore, in the thermal explosion, compared with HMX, TKX-50 generates less H2 and CO. Since the combustion heat of hydrogen is much higher than that of carbon, the more hydrogen generated, the higher the detonation heat obtained. Therefore, TKX-50 has a lower detonation heat, which also affects its specific kinetic energy.

The unusual effect of paraffin wax on the thermal decomposition of cyclotetramethylenetetranitramine.

The practical application of paraffin wax (PW) in cyclotetramethylenetetranitramine (HMX)-based polymer-bonded explosive (PBX) requires an understanding of its effect on the thermal decomposition of HMX. In this work, by comparing the thermal decomposition of HMX and a HMX/PW mixture, combined with crystal morphology analysis, molecular dynamics simulation, kinetic analysis, and gas product analysis, the unusual phenomenon and mechanism of the PW effect on the thermal decomposition of HMX were evaluated. During the initial decomposition, PW infiltrates the crystal surface of HMX, reduces the energy barrier for chemical bond dissociation, and induces the decomposition of molecules on HMX crystals, resulting in a lower initial decomposition temperature. PW consumes the active gas produced by HMX with further thermal decomposition and inhibits the dramatic increase of the HMX thermal decomposition rate. In decomposition kinetics, this effect is manifested as PW inhibits transition from an n-order reaction to an autocatalytic reaction.

Tanyptera (Tanyptera) hebeiensis Yang et Yang (Diptera: Tipulidae) newly recorded from Shandong, China: sequencing and phylogenetic analysis of the mitochondrial genome.

The genus Tanyptera Latreille, 1804 is recorded from Shandong Province, China for the first time with T. (T.) hebeiensis Yang et Yang, 1988 found in Mount Kunyu, Shandong. In this study, we report the complete mitochondrial genome sequence of T. (T.) hebeiensis, representing the first mitochondrial genome of the subfamily Ctenophorinae (Diptera: Tipulidae), which is a circular molecule of 15,888 bp with an AT content of 77.6%. The mitochondrial genome contains 13 protein-coding genes (PCGs), 22 transfer RNA genes (tRNAs), two ribosomal RNA genes (rRNAs), and a non-coding region. Gene overlaps are found at nine gene junctions, ranging from 1 to 8 bp in length. The canonical mitochondrial start codons for invertebrate mitochondrial genomes are found in 12 PCGs, except for COI which uses the uncanonical start codons TCG. Stop codons of 10 PCGs are invariably complete TAA and TAG, while COII, ND4, and ND5 end with a single thymine stop codon. Phylogenetic analysis reveals that the Pediciidae is a sister group to the remaining Tipuloidea, the Cylindrotomidae has a sister-group relationship with the Tipulidae, and the Limoniidae is not a monophyletic clade.

Preparation, Characterization, and Application of Magnetic Fe-SBA-15 Mesoporous Silica Molecular Sieves.

Magnetic Fe-SBA-15 mesoporous silica molecular sieves were prepared, characterized, and used for magnetic separation. Wet impregnation, drying, and calcination steps led to iron inclusion within the mesopores. Iron oxide was reduced to the metal form with hydrogen, and the magnetic Fe-SBA-15 was obtained. Fourier-transform infrared spectroscopy confirmed the preparation process from the oxide to metal forms. The structure of magnetic materials was confirmed by Mössbauer spectra. Powder X-ray diffraction data indicated that the structure of Fe-SBA-15 retained the host SBA-15 structure. Brunauer-Emmett-Teller analysis revealed a decrease in surface area and pore size, indicating Fe-SBA-15 coating on the inner surfaces. Scanning electron micrographs confirmed the decrease in size for modified SBA-15 particles. From scanning electron micrographs, it was found that the size of the modified SBA-15 particles decreased. Transmission electron micrographs also confirmed that modified SBA-15 retained the structure of the parent SBA-15 silica. Fe-SBA-15 exhibited strong magnetic properties, with a magnetization value of 8.8 emu g(-1). The iron content in Fe-SBA-15 was determined by atom adsorption spectroscopy. Fe-SBA-15 was successfully used for the magnetic separation of three aromatic compounds in water. Our results suggest wide applicability of Fe-SBA-15 magnetic materials for the rapid and efficient separation of various compounds.

Preparation of magnetic molecularly imprinted polymer for rapid determination of bisphenol A in environmental water and milk samples.

A magnetic molecularly imprinted polymer (M-MIP) of bisphenol A (BPA) was prepared by miniemulsion polymerization. The morphological and magnetic characteristics of the M-MIP were characterized by Fourier-transform infrared spectroscopy, transmission electron microscopy, and vibrating sample magnetometry. The adsorption capacities of the M-MIP and the nonimprinted polymer were investigated using static adsorption tests, and were found to be 390 and 270 mg g(-1), respectively. Competitive recognition studies of the M-MIP were performed with BPA and the structurally similar compound DES, and the M-MIP displayed high selectivity for BPA. A method based on molecularly imprinted solid-phase extraction assisted by magnetic separation was developed to extract BPA from environmental water and milk samples. Various parameters such as the mass of sorbent, the pH of the sample, the extraction time, and desorption conditions were optimized. Under selected conditions, extraction was completed in 15 min. High-performance liquid chromatography with UV detection was employed to determine BPA after the extraction. For water samples, the developed method exhibited a limit of detection (LOD) of 14 ng L(-1), a relative standard deviation of 2.7% (intraday), and spiked recoveries ranging from 89% to 106%. For milk samples, the LOD was 0.16 microg L(-1), recoveries ranged from 95% to 101%, and BPA was found in four samples at levels of 0.45-0.94 microg L(-1). The proposed method not only provides a rapid and reliable analysis but it also overcomes problems with conventional solid-phase extraction (SPE), such as the packing of the SPE column and the time-consuming nature of the process of loading large-volume samples.

Preparation of functionalized magnetic nanoparticulate sorbents for rapid extraction of biphenolic pollutants from environmental samples.

A new solid-phase extraction coupled with magnetic carrier technology was developed for extraction of bisphenol A (BPA) and diethylstilbestrol (DES) from water samples. The SPE sorbents, functionalized magnetic nanoparticles (Fe3O4@SiO2/beta-CD, core/shell), were synthesized in a two-stage system. The material was characterized by Fourier transform infrared spectroscopy, transmission electron microscopy, and a vibrating sample magnetometer. SPE extraction parameters, such as volume and pH of sample, adsorption time, and desorption conditions were optimized. Under selected conditions: 250 mL of water sample, 0.1 g of sorbents and elution with methanol (3 mL with 1% acetic acid), the extraction was completed in 25 min. SPE followed by HPLC was employed to determine BPA and DES in environmental samples. The developed method provided spiked recoveries of 80-105%, relative standard deviations of less than 7%, and LOD of BPA (20.0 ng/L) and DES (23.0 ng/L), respectively. The proposed method offered easy preparation of sorbents, rapid analysis, high enrichment yields, and reliable quantitative assay.

The complete mitochondrial genome and phylogenetic analysis of Tipula (Yamatotipula) nova Walker, 1848 (Diptera, Tipulidae) from Qingdao, Shandong, China.

The genus Tipula Linnaeus, 1758 is a large group of crane flies with more than 2400 known species from 41 subgenera. In this study, we report the first complete mitochondrial (mt) genome sequence of the subgenus Tipula (Yamatotipula), which is a circular molecule of 15,668 bp with an AT content of 77.2%. The mt genome contains 13 protein-coding genes, 22 tRNA genes, 2 rRNA genes, and a long non-coding region. Three conserved overlapping regions, 8 bp between tRNATrp and tRNACys , 7 bp between ATP8 and ATP6, and 7 bp between ND4 and ND4L, are found. Phylogenetic analysis reveals that the Tipulomorpha includes the family Trichoceridae and the Trichoceridae is sister-group to the remaining Tipulomorpha.

Studies on the thermal behavior and safety of a novel thermostable explosive BPTAP.

Thermal decomposition of a highly thermostable explosive dihydroxylammonium 2,4,8,10-tetranitro-benzopyrido-1,3a,6,6a-tetraazapentalene (BPTAP) was studied using conventional thermal analysis techniques (Thermal Gravimetric Analysis and Differential Scanning Calorimetry). To obtain more comprehensive insight into the kinetics mechanism of BPTAP decomposition, thermoanalytical experiments were performed under non-hermetic and hermetic conditions. Several widely used thermoanalytical data processing techniques based on model-free kinetics (Flynn-Wall-Ozawa, Kissinger, Freidman, numerical optimization) were studied and compared. Furthermore, to fully understand the thermal safety property of BPTAP, the kinetic model and the kinetic parameters were evaluated based on the non-isothermal DSC data by using a non-linear optimization method. The kinetic models of thermal decomposition of BPTAP under non-hermetic and hermetic conditions were different, which were identified as the generalized autocatalysis reaction and two parallel generalized autocatalysis reactions, respectively. On the basis of the aforementioned study, two important safety parameters including the time to maximum rate under adiabatic conditions and self-accelerating decomposition temperature for BPTAP in DEWAR were calculated and discussed.

Molecularly imprinted matrix solid-phase dispersion for extraction of chloramphenicol in fish tissues coupled with high-performance liquid chromatography determination.

The synthesis and evaluation of a molecularly imprinted polymer (MIP) as a selective matrix solid-phase dispersion (MSPD) sorbent, coupled with high-performance liquid chromatography for the efficient determination of chloramphenicol (CAP) in fish tissues are studied. The polymer was prepared using CAP as the template molecule, vinylpyridine as the functional monomer and ethylene glycol dimethacrylate as the cross-linking monomer, and sodium dodecyl sulfate as the surfactant in the presence of water as a solvent by miniemulsion polymerization. The CAP-imprinted polymers and nonimprinted polymers (NIPs) were characterized by Fourier transform IR spectroscopy, scanning electron microscopy, and static adsorption experiments. The CAP-imprinted material prepared showed high adsorption capacity, significant selectivity, and good site accessibility. The maximum static adsorption capacity of the CAP-imprinted and the NIP material for CAP was 78.4 and 59.9 mg g(-1), respectively. The relative selectivity factors of this CAP-imprinted material were larger than 1.9. Several parameters influencing the MSPD process were optimized. Finally, the CAP-imprinted polymers were used as the sorbent in MSPD to determine CAP in three kinds of fishes and resulted in satisfactory recovery in the range 89.8-101.43%. CAP-imprinted polymer as a sorbent in MSPD is better than C18 and attapulgite in terms of both recovery and percent relative standard deviation. The baseline noise was measured from a chromatogram of a blank fish sample which was treated after the MSPD procedure using CAP-imprinted polymer as a sorbent. Signal values of 3 times the noise (signal-to-noise ratio of 3) and 10 times the noise (signal-to-noise ratio of 10) were used to calculate the limit of detection and the limit of quantitation of the calibration curve. The limit of detection for CAP was 1.2 ng g(-1) and the limit of quantitation was 3.9 ng g(-1).

Selective solid-phase extraction using molecular imprinted polymer for the analysis of diethylstilbestrol.

A simple imprinted amino-functionalized silica gel material was synthesized by combining a surface molecular imprinting technique with a sol-gel process for solid-phase extraction-high performance liquid chromatography (SPE-HPLC) determination of diethylstilbestrol (DES). Activated silica gel was used as the supporter and non-imprinted silica sorbent was synthesized without the addition of DES using the same procedure as that of DES-imprinted silica sorbent. Compared with non-imprinted polymer particles, the prepared DES-imprinted silica sorbent showed high adsorption capacity, significant selectivity, good site accessibility and fast binding kinetics for DES. The maximum static adsorption capacity of the DES-imprinted and non-imprinted silica sorbent for DES was 62.58mgg(-1) and 19.89mgg(-1), respectively. The relatively selective factor value of this DES-imprinted silica sorbent was 61.7 at the level of 50mgL(-1). And the uptake kinetics was fairly rapid so that the adsorbent equilibrium was achieved within 10min. Furthermore, the DES-imprinted polymers were used as the sorbent in solid-phase extraction to determine DES in fish samples. The MIP-SPE-HPLC method showed higher selectivity and good recoveries higher than 87.5% (R.S.D. 11.6%).

A cell clone strain from Mythimna separata (Lepidoptera: Noctuidae) highly susceptible to Autographa californica multiple nucleopolyhedrovirus (AcMNPV) and M. separata NPV (MsNPV).

In this study, we describe a cell line, Ms-10C, cloned from the line QAU-Ms-E-10 (simplified Ms-10), an embryonic line from Mythimna separata. The cloned cell line was significantly more sensitive to nucleopolyhedrovirus (NPV). Ms-10C cells were mainly spherical with a diameter of 14.42 ± 2.23 µm. DNA amplification fingerprinting (DAF) confirmed the profile of PCR-amplified bands of the cloned cell line was consistent with those of the parental cell line, Ms-10. The sequencing result of the mitochondrial cytochrome c oxidase I (mtCO I) fragment confirmed that the amplified 636-bps mtCOI fragment was 100% identical to that of M. separata. Its chromosomes exhibited the typical characters of lepidopteran cell lines. Its population doubling time was 42.2 h at 27°C. Ms-10C was more sensitive than Ms-10 to both Autographa californica multiple nucleopolyhedrovirus (AcMNPV) and M. separata nucleopolyhedrovirus (MsNPV). At 4 d post infection, the infection rates of two viruses reached 94.2 and 92.3%, respectively. The availability of this cell clone strain will provide a useful tool for the basic research on nucleopolyhedrovirus and for potential application in expression of recombinant proteins with baculovirus expression vector system.

Preparation and characterization of an amphipathic magnetic nanosphere.

The amphipathic magnetic nanospheres were synthesized using C8 and polyethylene glycol as ligands. Their morphology, structure, and composition were characterized by transmission electron microscope, Fourier transform infrared, and elementary analysis. The prepared materials presented uniform sphere with size distribution about 200 nm. The magnetic characteristics of magnetic nanomaterials were measured by vibrating sample magnetometer. The target products had a saturation magnetization value of 50 emu g(-1) and superparamagnetism. The adsorption capability was also studied by static tests, and the material was applied to enrich benzenesulfonamide from calf serum. The results exhibited that the C8-PEG phase owned better adsorption capability, biocompatible property, and dispersivity in aqueous samples.

Hyperbranched polymers containing stereocontorted cores as on-line solid-phase microextraction adsorbent for polycyclic aromatic hydrocarbons.

A polymer monolith column was prepared using click chemistry for on-line solid phase microextraction of polycyclic aromatic hydrocarbons (PAHs), using 2,2',7,7'-tetraethynyl-9,9'-spirobifluorene(TES) and 1,4-bis(6-azidoalkoxy)benzene (BAB) as monomers, and Cu(PPh3)3Br as the catalyst. The polymer with spirocyclic cross-links was porous and presented an appropriate interspace of PAHs. Enrichment of PAHs, in the range of 100 to more than 1000 times, was due to the π-π stacking interaction and the effect of small size. The factors affecting the on-line microextraction efficiency were optimized, and the analytical conditions were evaluated to ensure reliability.

Synthesis of molecularly imprinted polymer using attapulgite as matrix by ultrasonic irradiation for simultaneous on-line solid phase extraction and high performance liquid chromatography determination of four estrogens.

A molecularly imprinted polymer was synthesized by ultrasonic irradiation, with attapulgite as matrix using ß-naphthol as the template molecule, acryloyl-ß-cyclodextrin as the functional monomer, and N,N-methylenebiacrylamide as the cross-linking agent, respectively. The imprinted polymer was characterized by infrared spectroscopy and transmission electron microscopy. Compared to polymers prepared by traditional heat sources, the molecularly imprinted polymer synthesized by ultrasonic irradiation had better selectivity and faster adsorption kinetics to estriol, estradiol, estrone and diethylstilbestrol. Using the imprinted polymer as the packing material for on-line solid-phase extraction, the above four estrogens in milk samples were concentrated and analyzed. The limits of detection for these estrogens were in the range of 1-8 ng g(-1) and reproducibility were less than 5.1% as RSDs (n=6) with milk samples spiked at 100 and 1000 ng g(-1) of each analyte.