Simultaneous analysis of different classes of phytohormones in coconut (Cocos nucifera L.) water using high-performance liquid chromatography and liquid chromatography-tandem mass spectrometry after solid-phase extraction

Coconut (Cocos nucifera L.) water, which contains many uncharacterized phytohormones is extensively used as a growth promoting supplement in plant tissue culture. In this paper, a high-performance liquid chromatography (HPLC) method was developed for the simultaneous determination of various classes phytohormones, including indole-3-acetic acid (IAA), indole-3-butyric acid (IBA), abscisic acid (ABA), gibberellic acid (GA), zeatin (Z), N⁶-benzyladenine (BA), α-naphthaleneacetic acid (NAA) and 2,4-dichlorophenoxyacetic acid (2,4-D) in young coconut water (CW). The analysis was carried out using a reverse-phase HPLC gradient elution, with an aqueous mobile phase (containing 0.1% formic acid, pH adjusted to 3.2 with triethylamine (TEA)) modified by methanol, and solute detection made at 265 nm wavelength. The method was validated for specificity, quantification, accuracy and precision. After preconcentration of putative endogenous phytohormones in CW using C₁₈ solid-phase extraction (SPE) cartridges, the HPLC method was able to screen for putative endogenous phytohormones present in CW. Finally, the identities of the putative phytohormones present in CW were further confirmed using independent liquid chromatography–tandem mass spectrometry (LC–MS/MS) equipped with an electrospray ionization (ESI) interface.     

Determination of phytohormones in plant samples based on the precolumn fluorescent derivatization with 1,3,5,7-tetramethyl-8-aminozide-difluoroboradiaza-s-indacene by HPLC for routine use

Six phytohormones including indole butyric acid (IBA), naphthalene acetic acid (NAA), 2,4-dichloro-phenoxy acetic acid (2,4-D), indole-3-acetic acid (IAA), abscisic acid (ABA), and salicylic acid (SA) in crude plant extractions have been quantitated by means of high-performance liquid chromatography (HPLC) with fluorescence detection based on the precolumn derivatization using 1,3,5,7-tetramethyl-8-aminozide-difluoroboradiaza-s-indacene (BODIPY-aminozide), a fluorescent reagent synthesized in our lab recently. The optimization of derivatization conditions was carefully studied by an L(25) (5(6)) orthogonal array design (OAD) with five factors at five levels that are important influence parameters in the improvement of derivatization efficiency. The separation conditions were also studied in detail. Under the optimal conditions, the detection limits (S/N=3) of the six phytohormones were found from 0.12 to 0.75 nM. The proposed method was the first investigation of aminozide for the analysis of phytohormones and has been successfully applied to the determination of phytohormones in plant samples such as cucumber and tomato with recoveries of 94-105%.     

Simultaneous determination of four plant hormones in bananas by molecularly imprinted solid-phase extraction coupled with high performance liquid chromatography

A highly selective molecularly imprinted solid-phase extraction (MISPE) combined with liquid chromatography-ultraviolet detection was developed for the simultaneous isolation and determination of four plant hormones including indole-3-acetic acid (IAA), indole-3-propionic acid (IPA), indole-3-butyric acid (IBA) and 1-naphthaleneacetic acid (NAA) in banana samples. The new molecularly imprinted microspheres (MIMs) prepared by aqueous suspension polymerization using 3-hydroxy-2-naphthoic acid and 1-methylpiperazine as mimic templates performed with high selectivity and affinity for the four plant hormones, and applied as selective sorbents of solid-phase extraction could effectively eliminate the interferences of the banana matrix. Good linearity was obtained in a range of 0.04-4.00 μg g(-1) and the recoveries of the four plant hormones at three spiked levels ranged from 78.5 to 107.7% with the relative standard deviations (RSD) of less than 4.6%. The developed MISPE-HPLC protocol obviously improved the selectivity and eliminated the effect of template leakage on quantitative analysis, and could be applied for the determination of plant hormones in complicated biological samples.     

植物生长激素的毛细管胶束电动色谱法分离

以高效毛细管胶束电动色谱法对赤霉素（ＧＡ）、脱落酸（ＡＢＡ）、吲哚丁酸（ＩＢＡ）、吲哚乙酸（ＩＡＡ）、萘乙酸（ＮＡＡ）等植物生长激素的分离和测定进行了研究。考察了各种操作参数及有机添加剂对分离的影响,得到良好的分离结果。对各组分进行了定量测定研究,ＡＢＡ、ＧＡ、ＩＢＡ、ＩＡＡ及ＮＡＡ的最低检测浓度依次为５．０,３．０,０．５８,０．１５,０．１４ｍｇ／Ｌ。     

Diamino moiety functionalized silica nanoparticles as pseudostationary phase in capillary electrochromatography separation of plant auxins

A novel and simple method for the preparation of silica nanoparticles having surface-functionalized diamino moiety (dASNPs) was reported in our paper and characterized using scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectrometry, and thermogravimetry techniques. To test this method practically, in this contribution we describe the enhanced separation of four plant auxins - indole-3-acetic acid (IAA), indole-3-butyric acid (IBA), 2,4-dichlorophenoxyacetic acid (dCPAA), and 2-(1-naphthyl) acetic acid (NAA) - by capillary electrochromatography using diamino moiety functionalized silica nanoparticles as pseudostationary phase (PSP) in the running buffer. The effect of pH, buffer concentration, and diamino moiety functionalized silica nanoparticles concentration on the selectivity of separation was investigated. A combination of the nanoparticles and running buffer reversed the electroosmotic direction making possible the rapid and efficient separation of the auxins from the auxins migrated in the same direction with the EOF under optimum experimental conditions. A good resolution of four auxins was obtained within 5.5 min under optimum experimental conditions. The precision (RSD, n = 5) was in the range of 0.72-0.91% and 1.89-2.23% for migration time and peak area response, respectively. The detection limits were 0.48, 0.44, 0.46, and 0.42 μM for NAA, IBA, IAA, and dCPAA, respectively. Furthermore, the method was successfully tested for the determination of IAA in the grapes.     

In vitro multiplication in Kaempferia galanga linn

Kaempferia galanga is an important medicinal plant that is facing threat of extinction owing to indiscriminate and unsustainable harvesting in the wild. Conventional breeding is difficult in this plant, and in vitro multiplication is important to conservation and propagation. Leaf and rhizome explants of Kaempferia were aseptically cultured on MS medium with various combinations of indole-3-acetic acid (IAA), benzyl amino purine (BAP), napthalene acetic acid (NAA), 2-4-dichlorophenoxy acetic acid (2,4-D) and kinetin at concentrations ranging from 0.5 to 2.5 mg/L. High-frequency organogenesis and multiple shoot regeneration was induced from rhizome explants on MS medium supplemented with 0.5 mg/L of IAA and 2.5 mg/L of BAP. Rooting was induced in MS medium with 0.5 mg/L of IAA and 2 mg/L of BAP.     

Multi-walled carbon nanotube as a solid phase extraction adsorbent for analysis of indole-3-butyric acid and 1-naphthylacetic acid in plant samples

In this work,a new sample pretreatment method prior to HPLC separations was developed for the determination of auxins in plant samples.Owing to its large surface area and high adsorption capacity, multi-walled carbon nanotube(MWCNT) was chosen as the adsorbent for the extraction of auxins from plant samples.In this study,two important auxins were selected as model analytes,namely indole-3-butyric acid(IRA) and 1-naphthylacetic acid(NAA).They could be extracted and concentrated due to theirπ-πstacking interactions with MWCNT.Then HPLC-UV was introduced to detect IBA and NAA after sample pretreatment.Factors that may affect the enrichment efficiency were investigated and optimized.Comparative studies showed that MWCNT was superior to C18 for the extraction of the two analytes.Validation experiments showed that the optimized method had good linearity(0.9998 and 0.9960),high recovery(81.4%-85.4%),and low detection limits(0.0030 mg/L and 0.0012 mg/L).The results indicated that the novel method had advantages of convenience,good sensitivity,high efficiency, and it was feasible for the determination of auxins in plant samples.     

Plant Hormone Analysis by Countercurrent Chromatography

Abstract

Countercurrent chromatography (CCC) has been successfully applied for the separation of plant hormones; namely, indole auxins, gibberellins, cytokinins and abscisic acid. In our present study three different types of CCC devices were evaluated for their performance in separation of plant hormones with a special emphasis on analysis and purification of abscisic acid (ABA). A large-scale preparative CCC apparatus consisting of a slowly rotating coil assembly was used for preliminary separations of ABA from a large volume of crude plant extracts. The toroidal coil planet centrifuge (CPC) for analytical-scale separations was subsequently applied for purification of ABA, the final confirmation being obtained by HPLC and combined gas chromatographic-mass spectrometric method. This two-step procedure utilizing preparative CCC and toroidal CPC was successfully applied for determination of ABA content in several plant tissues. A recently introduced high-speed CCC apparatus was tested for semipreparative separation of ABA and indole-3-acetic acid. The method yielded high peak resolution within 2 hours.     

全自动在线固相萃取-液相色谱-串联质谱法同时检测水稻中6种内源性植物激素

建立了同时检测水稻中6种内源性植物激素脱落酸( Abscisic acid,ABA)、吲哚-3-乙酸( Indole-3-acetic acid, IAA)、水杨酸( Salicylic acid,SA)、茉莉酸( Jasmonic acid,JA)、吲哚-3-丙酸( Indole-3-propionic acid, IPA)和吲哚-3-丁酸( Indole-3-butyric acid,IBA)的全自动在线固相萃取-液相色谱-串联质谱方法。植物样品经过甲醇提取,采用C18固相萃取柱富集净化,流动相将待测物洗脱至C18分析色谱柱进行分离,最终使用串联四极杆质谱进行检测。方法的线性范围为8~320μg/L,相关系数为R2≥0.99;方法的检出限(S/N=3)范围为0.1~0.8μg/kg;实际样品中方法回收率范围为71.2%~126%,RSD<13%。应用本方法快速、准确地检测了水稻幼穗中多种内源性植物激素的含量,并与目前植物学领域内常用的检测方法进行了比较。同时,本方法对水稻受伤叶片的内源植物激素含量变化进行了定量分析,其含量随受伤时间的变化趋势与其生物背景的实验结果相吻合。     

Preparation of magnetic indole-3-acetic acid imprinted polymer beads with 4-vinylpyridine and β-cyclodextrin as binary monomer via microwave heating initiated polymerization and their application to trace analysis of auxins in plant tissues

Auxin is a crucial phytohormone for precise control of growth and development of plants. Due to its low concentration in plant tissues which are rich in interfering substances, the accurate determination of auxins remains a challenge. In this paper, a new strategy for isolation and enrichment of auxins from plant tissues was obtained by the magnetic molecularly imprinted polymer (mag-MIP) beads, which were prepared by microwave heating initiated suspension polymerization using indole-3-acetic acid (IAA) as template. In order to obtain higher selective recognition cavities, an enhanced imprinting method based on binary functional monomers, 4-vinylpyridine (4-VP) and β-cyclodextrin (β-CD), was adopted for IAA imprinting. The morphological and magnetic characteristics of the mag-MIP beads were characterized by scanning electron microscopy, Fourier-transform infrared spectroscopy and vibrating sample magnetometry. A majority of resultant beads were within the size range of 80-150μm. Porous surface morphology and good magnetic property were observed. Furthermore, the mag-MIP beads fabricated with 4-VP and β-CD as binary functional monomers exhibited improved recognition ability to IAA, as compared with the mag-MIP beads prepared with the individual monomer separately. Competitive rebinding experiment results revealed that the mag-MIP beads exhibited a higher specific recognition for the template than the non-imprinted polymer (mag-NIP) beads. An extraction method by mag-MIP beads coupled with high performance liquid chromatography (HPLC) was developed for determination of IAA and indole-3-butyric acid (IBA) in plant tissues. Linear ranges for IAA and IBA were in the range of 7.00-100.0μgL(-1) and 10.0-100.0μgL(-1), and the detection limits were 3.9 and 7.4μgL(-1), respectively. The analytical performance was also estimated by seedlings or immature embryos samples from three different plant tissues, pea, rice and wheat. Recoveries were in the range of 70.1-93.5%. The results show that the present imprinting method is a promising approach for preparation of selective adsorbents for sample preparation of auxin analysis in plant tissues.     

Dual-cloud point extraction and tertiary amine labeling for selective and sensitive capillary electrophoresis-electrochemiluminescent detection of auxins

The low concentrations of the auxins in samples of plant tissue necessitate the use of selective and sensitive techniques for their quantification. Herein a selective and sensitive method based on dual-cloud point extraction (dCPE) and tertiary amine labeling for the quantification of indole-3-acetic acid (IAA) and indole-3-butyric acid (IBA) by capillary electrophoresis-electrochemiluminescence (CE-ECL) is proposed. The procedure for dCPE included two cloud point processes with Triton X-114 as the extractant. The two auxins became hydrophobic in an acidic solution and were extracted into surfactant-rich phase after the first cloud point procedure. They were then back-extracted into the alkaline aqueous phase during the second cloud point step. The extracted auxins were reacted with 2-(2-aminoethyl)-1-methylpyrrolidine (AEMP) in acetonitrile that contained N,N′-dicyclohexylcarbodiimide and 3,4-dihydro-3-hydroxy-4-oxo-1,2,3-benzotriazine to produce their AEMP-derivatives. The two auxin-AEMP-derivatives were subjected into CE and detected by Ru(bpy)₃²⁺-based ECL. The preconcentration factors for IAA and IBA with dCPE were 40.5 and 43.4, respectively. The on-capillary detection limits (S/N = 3) were 2.5 and 2.8 nM for IAA and IBA. This protocol presents a clear advantage in that it reduces the interference from the matrixes extensively and gives a high sensitivity for the detection of auxins. The proposed method was applied successfully to the detection of the two auxins in acacia tender leaves, buds, and bean sprout.     

Development of sample preparation method for auxin analysis in plants by vacuum microwave-assisted extraction combined with molecularly imprinted clean-up procedure

A novel sample preparation method for auxin analysis in plant samples was developed by vacuum microwave-assisted extraction (VMAE) followed by molecularly imprinted clean-up procedure. The method was based on two steps. In the first one, conventional solvent extraction was replaced by VMAE for extraction of auxins from plant tissues. This step provided efficient extraction of 3-indole acetic acid (IAA) from plant with dramatically decreased extraction time, furthermore prevented auxins from degradation by creating a reduced oxygen environment under vacuum condition. In the second step, the raw extract of VMAE was further subjected to a clean-up procedure by magnetic molecularly imprinted polymer (MIP) beads. Owing to the high molecular recognition ability of the magnetic MIP beads for IAA and 3-indole-butyric acid (IBA), the two target auxins in plants can be selectively enriched and the interfering substance can be eliminated by dealing with a magnetic separation procedure. Both the VMAE and the molecularly imprinted clean-up conditions were investigated. The proposed sample preparation method was coupled with high-performance liquid chromatogram and fluorescence detection for determination of IAA and IBA in peas and rice. The detection limits obtained for IAA and IBA were 0.47 and 1.6 ng/mL and the relative standard deviation were 2.3% and 2.1%, respectively. The IAA contents in pea seeds, pea embryo, pea roots and rice seeds were determined. The recoveries were ranged from 70.0% to 85.6%. The proposed method was also applied to investigate the developmental profiles of IAA concentration in pea seeds and rice seeds during seed germination.     

Determination of indole-3-acetic acid and indole-3-butyric acid in mung bean sprouts using high performance liquid chromatography with immobilized Ru(bpy)3-KMnO4 chemiluminescence detection

A novel method for determination of indole-3-acetic acid (IAA) and indole-3-butyric acid (IBA) in an extract from mung bean sprouts using high performance liquid chromatography (HPLC) with chemiluminescence (CL) detection is described. The method is based on the CL reaction of auxin (indole-3-acetic acid and indole-3-butyric acid) with acidic potassium permanganate (KMnO₄) and tris(2,2′-bipyridyl)ruthenium(II), which was immobilized on the cationic ion-exchange resin. The chromatographic separation was performed on a Nucleosil RP-C18 column (i.d.: 250 mm × 4.6 mm, particle size: 5 μm, pore size: 100) with an isocratic mobile phase consisting of methanol-water-acetic acid (45:55:1, v/v/v). At a flow rate of 1.0 mL min⁻¹, the total run time was 20 min. Under the optimal conditions, the linear ranges were 5.0 × 10⁻⁸ to 5.0 × 10⁻⁶ g mL⁻¹ and 5.0 × 10⁻⁷ to 1.0 × 10⁻⁵ g mL⁻¹ for IAA and IBA, respectively. The detection limits were 2.0 × 10⁻⁸ g mL⁻¹ and 2.0 × 10⁻⁷ g mL⁻¹ for IAA and IBA, respectively. The relative standard deviation (RSD) of intra-day were 3.1% and 2.3% (n = 11) for 2 × 10⁻⁶ g mL⁻¹ IAA and 2 × 10⁻⁶ g mL⁻¹ IBA; The relative standard deviations of inter-day precision were 6.9% and 4.9% for 2 × 10⁻⁶ g mL⁻¹ IAA and 2 × 10⁻⁶ g mL⁻¹ IBA. The proposed method had been successfully applied to the determination of auxin in mung bean sprouts.     

Polydopamine-based permanent coating capillary electrochromatography for auxin determination

A novel, simple, and economical method for the preparation of open-tubular capillary column using polydopamine coating was reported for the first time. After the capillary was filled with dopamine solution for 20h, polydopamine was formed and deposited on the inner wall of capillary as permanent coating via the oxidation of dopamine by the oxygen dissolved in the solution. Moreover, the electroosmotic flow of the coated capillaries was measured to be dependent on the repetitive coating times. The performance of the polydopamine-coated capillary electrochromatography was validated by the analysis of four auxins, indole-3-butyric acid (IBA), 2,4-dichlorophenoxyacetic acid (dCPAA), indole-3-acetic acid (IAA), and phenoxyacetic acid (PAA). The precisions (RSD, n=5) were in the range of 1.6-2.4% for migration time, 4.0-6.5% for peak area response, and 3.6-4.7% for peak height response for the four auxins at 1microgmL(-1) level. The detection limits were 0.185, 0.172, 0.177, and 0.259microg/mL for IBA, dCPAA, IAA, and PAA, respectively. The method was successfully used to the determination of IAA in the culture media of IAA-producing bacteria.     

超高效液相色谱-串联质谱法同时检测植物叶片中吲哚-3-乙酸及其3种氧化产物

以玉米叶片为供试材料,建立了同时测定植物体内吲哚-3-乙酸(IAA)及其3种氧化产物吲哚-3-甲醇(ICI)、吲哚-3-甲醛(ICA)、吲哚-3-羧酸(IFA)含量的超高效液相色谱-串联质谱(UPLC-MS/MS)方法。结果表明,该方法对IAA及其3种氧化产物检测的线性、精密度和重复性较好,灵敏度较高,4种化合物的检出限为0.002~1.63μg/kg,定量下限为0.007~5.43μg/kg;方法的加标回收率为89.5%~95.3%,相对标准偏差为2.3%~5.1%。玉米叶片的实际测定结果表明,IAA,ICI,ICA和IFA的含量分别为(196.25±7.10),(26.21±2.13),(18.65±2.02),(13.62±2.06)μg/kg。该方法已成功应用于小麦、豌豆、硬毛刺苞菊叶片的测定,通用性较好。     

亚种间杂交稻内源激素的高效液相测定法

 建立了一种快速、提取率高的从植物中提取内源激素的样品处理方法 ,并研究了高效液相法测定亚种间杂交稻的 4种内源激素 :赤霉素 (GA3 )、3 吲哚乙酸 (IAA)、玉米素 (Z)和脱落酸 (ABA)的条件。采用WatersC18反相柱 (4 6mmi.d .× 2 5 0mm ,5 μm) ,SPD 6AV紫外检测器。以甲醇 水 乙酸 (体积比为 45∶5 4 2∶0 8)溶液为流动相 ,流速 1 0mL/min ;进样量 2 0 μL ;检测波长 2 5 4nm ;选用外标法进行定量测定。其回收率高 ,检出限分别为GA3 0 5mg/L ,IAA 0 1mg/L ,Z 0 3mg/L ,ABA 0 0 3mg/L。该法快速、灵敏、准确。     

Chemiluminescence determination of indole derivatives in human body fluids and soil by flow injection analysis using potassium permanganate

A simple, sensitive and rapid flow-injection chemiluminescence (CL) method has been developed for the determination of indole derivatives including indole-2,3-dione (isatin) and indole-3-acetic acid (IAA), based on the increased CL reaction of potassium permanganate-formaldehyde system in acidic medium. Strong CL was observed when the indole derivatives were injected into the acidic potassium permanganate solution in a flow-cell. Under the optimum conditions, the linear range of the determination was 0.1–100.0 µM for isatin and 0.01–10.0 µM for IAA. The detection limit (3σ) was 10.0 nM for isatin and 1.0 nM for IAA. The method has been successfully applied to the determination of isatin in biological samples and of IAA in biological samples and soil extracts with satisfactory results.     

Separation of plant hormones from biofertilizer by capillary electrophoresis using a capillary coated dynamically with polycationic polymers.

A new, simple and rapid capillary electrophoresis (CE) method, using hexadimethrine bromide (HDB) as electroosmotic flow (EOF) modifier, was developed for the identification and quantitative determination of four plant hormones, including gibberellin A3 (GA3), indole-3-acetic acid (IAA), alpha-naphthaleneacetic acid (NAA) and 4-chlorophenoxyacetic acid (4-CA). The optimum separation was achieved with 20 mM borate buffer at pH 10.00 containing 0.005% (w/v) of HDB. The applied voltage was -25 kV and the capillary temperature was kept constant at 25 degrees C. Salicylic acid was used as internal standard for quantification. The calibration dependencies exhibited good linearity within the ratios of the concentrations of standard samples and internal standard and the ratios of the peak areas of samples and internal standard. The correlation coefficients were from 0.9952 to 0.9997. The relative standard deviations of migration times and peak areas were < 1.93 and 6.84%, respectively. The effects of buffer pH, the concentration of HDB and the voltage on the resolution were studied systematically. By this method, the contents of plant hormone in biofertilizer were successfully determined within 7 min, with satisfactory repeatability and recovery.     

Simultaneous determination of several phytohormones in natural coconut juice by hollow fiber-based liquid–liquid–liquid microextraction-high performance liquid chromatography

A simple, selective, sensitive and inexpensive method of hollow fiber-based liquid–liquid–liquid microextraction (HF-LLLME) combined with high performance liquid chromatography (HPLC)-ultraviolet (UV) detection was developed for the determination of four acidic phytohormones (salicylic acid (SA), indole-3-acetic acid (IAA), (±) abscisic acid (ABA) and (±) jasmonic acid (JA)) in natural coconut juice. To the best of our knowledge, this is the first report on the use of liquid phase microextraction (LPME) as a sample pretreatment technique for the simultaneous analysis of several phytohormones. Using phenetole to fill the pores of hollow fiber as the organic phase, 0.1 mol L⁻¹ NaOH solution in the lumen of hollow fiber as the acceptor phase and 1 mol L⁻¹ HCl as the donor phase, a simultaneous preconcentration of four target phytohormones was realized. The acceptor phase was finally withdrawn into the microsyringe and directly injected into HPLC for the separation and quantification of the target phytohormones. The factors affecting the extraction efficiency of four phytohormones by HF-LLLME were optimized with orthogonal design experiment, and the data was analyzed by Statistical Product and Service Solutions (SPSS) software. Under the optimized conditions, the enrichment factors for SA, IAA, ABA and JA were 243, 215, 52 and 48, with the detection limits (S/N = 3) of 4.6, 1.3, 0.9 ng mL⁻¹ and 8.8 μg mL⁻¹, respectively. The relative standard deviations (RSDs, n = 7) were 7.9, 4.9, 6.8% at 50 ng mL⁻¹ level for SA, IAA, ABA and 8.4% at 500 μg mL⁻¹ for JA, respectively. To evaluate the accuracy of the method, the developed method was applied for the simultaneous analysis of several phytohormones in five natural coconut juice samples, and the recoveries for the spiked samples were in the range of 88.3–119.1%.     

Direct analysis in real time mass spectrometry combined with single-drop liquid–liquid–liquid microextraction for the rapid analysis of multiple phytohormones in fruit juice

A rapid, simple, and efficient method for the fast determination of multiple phytohormones was developed in this work, based on single-drop liquid-liquid-liquid microextraction (SD-LLLME) combined with direct analysis in real-time mass spectrometry (DART-MS). Six phytohormones--indole-3-acetic acid (IAA), indole-3-butyric acid (IBA), jasmonic acid (JA), salicylic acid (SA), abscisic acid (ABA), and gibberellin A(3) (GA(3))--were analyzed simultaneously using this method, and the conditions employed for DART-MS and SD-LLLME were optimized systematically. Satisfactory results were obtained in terms of linearity (R (2) values for all phytohormones were 0.991-0.996), sensitivity (limits of detection were 0.65-72 ng/mL), and repeatability (RSD values were 6.9-14%). In addition, the proposed method was applied to determine the endogenous phytohormones in three kinds of fruit juice. Different concentrations of phytohormones were detected with satisfactory recoveries, and the whole analytical procedure took no more than 30 min. Therefore, this combination of SD-LLLME and DART-MS was shown to be a suitable and effective approach for the fast analysis of targets present at trace level concentrations in complex matrices.