Table 1.
Selected examples of microextraction of bioactive compounds using solid sorbents.
| Extraction format/methodology | Target analytes/sample | Method description/analytical performance (LOD) | References |
|---|---|---|---|
| HS-SPME | VOCs/mangoes | Blended 5.0 g juice + 1.5 g of NaCl in 15 mL capped vial, 80 rpm stirring; 10 min-equilibration; 30 min DVB/Carboxen/PDMS extraction (40°C); GC desorption | (51) |
| HS-SPME | VOCs/tangerines | 5 mL tangerine juice or 250 mg peels (20 mL HS glass vial, magnetic stirring); NaCl 10% (w/v); HS-SPME extraction (40 min, 40°C); GC-MS analysis | (52) |
| EPT-SPME/PT-SPME | Alkaloids, flavonoids/TCM | Sample pretreatment: liquid samples (1.0 mL) centrifugation (5,000 g, 10 min, RT); EPT-SPME: hollow polypropylene fiber attached to 1,000 μL pipette tip; 10 mg sorbent + 2 mg sodium bicarbonate placed in the tip; 500 μL sample supernatant + 100 μL sodium dihydrogen phosphate (0.5 mol L−1) loaded into the tip; 1.2 min dwelling; sample withdrawn; washing (200 μL water); desorption (100 μL MeOH-ammonia (90:10, v/v) withdrawn into the tip; 1.5 min dwelling; solvent withdraw; UHPLC-UV analysis (20 μL). PT-SPME: 10 mg sorbent placed in the tip; 500 μL sample supernatant + 100 μL phosphate buffer (0.5 mol L−1, pH 6.5) loaded into the tip; 1.2 min dwelling; 200 μL water washing; desorption: 100 μL MeOH: ammonia (90:10, v/v) withdrawn into the tip; 1.5 min dwelling; UHPLC analysis/1.02–2.98 μ gL−1 | (53) |
| HS-SPME | Trans-resveratrol/wines, grape juices | 30 min extraction (1.5-mL amber vials; HS-SPME with magnetic stirring; 6.6% EtOH + 10% NaCl); 15 min fiber soaking (mobile phase); desorption; LC-UV analysis/0.4 ng mL−1 | (54) |
| MMF-SPME | Phenolic acids/fruit juices | MeOH + water activation; 20 mL sample (25 mL vial + stirring bar, 8 × 2 mm); MMF direct immersion in sample solution; 40 min, low stirring; MeOH/1% AA aqueous (v/v, 90/10) desorption (400 μL, 20 min)/0.17–0.57 μg L−1 | (55) |
| NTME | VOCs/lemon | 250 mg sample (20 ml HS glass vial), equilibration (10 min, 50°C); 30 mL gas phase (30 cycles) loaded through the NTD (pre-attached to 1 mL syringe); GC-MS analysis | (56) |
| PT-SPE | Flavonoids/TCM | 100 μL sample loaded into tip (5 μL s−1 flow rate); 1.0 min dwelling; 500 μL water washing; 100 μL ACN desorption (5 min dwelling); HPLC analysis (20 μL). SPE: 500 μL sample loaded (positive pressure) onto preconditioned Sep-Pac C18-360 mg cartridge (3.0 mL MeOH + 3.0 mL water); 2 × 5 mL water washing; 3.0 mL ACN elution; evaporation to dryness (40°C, N2 stream); 100 μL ACN reconstitution, vortex, and centrifugation (10,000 rpm, 10 min); HPLC-UV analysis (2 μL)/0.027–0.045 μg mL−1 | (57) |
| M-MWCNTs-SPE | GA/pomegranate rind | 5 g dry pomegranate powder + 50 mL EtOH (20%, v/v); filtration; pomegranate rind extract (20 mL) + M-MWCNTs@GA-MIPs (30 mg) incubation (oscillator, 60 min); collect M-MCNTs@GA-MIPs with captured GA (magnet); GA desorption (EtOH-HAc (95:5, v/v); evaporation to dryness (N2 stream); MeOH reconstitution (5 mL); HPLC-UV analysis/0.001 μg mL−1 | (58) |
| M-MIP-SPE | Chlorogenic acid/ fruit juices | 30 mL fruit juice + 60 mg Fe3O4@CGA-MIPs; 30 min, RT; Fe3O4@CGA-MIPs separated magnetically, EtOH–HAc (95:5, v/v) elution (6 h); filtration (0.22 μm nylon membrane); HPLC-UV analysis/0.01 μg mL−1 | (59) |
| M-SPE | Flavonoids/ tea, wine | 2 mL samples into a centrifuge tube; 8 mg magnetic graphene composites (GO/Fe3O4); 2 mL phosphate buffered solution (0.02 M); sonication (5 min), vortex (15 min in an oscillator); remove supernatant while holding GO/Fe3O4 composites with a magnet; target analytes elution (2 × 1 mL acetone containing 1 % HAc); evaporate to dryness (60 °C; N2 stream); MeOH reconstitution (0.5 mL); filtration (0.45 μm); HPLC analysis (10 μL)/0.2-6.0 ng mL−1 | (60) |
| MISM-PT | GA/juices | 1 mL MeOH + 1 mL water washing; 6.0 mL orange juice sample loaded on MISM-PT (0.15 mL min−1); 150 μL hexane washing; 250 μL gallic acid elution; extract concentrated to dryness (N2 stream); dissolved in 50 μL mobile phase; HPLC-UV analysis (20 μL)/7.0 μg L−1 | (61) |
| PT-SPE | Estradiol/milk | MIOMS-ir (3 mg) packed into 100 μL pipette tip (cotton capped at both ends); preconditioning (1 mL MeOH + 0.5 mL water); 0.5 mL milk sample loading; 0.3 mL water washing; 0.5 mL ACN-acetic acid (96:4, v/v) elution; evaporation to dryness (N2 by gentle nitrogen blowing); residue redissolving in the mobile phase (0.5 mL) for LC-FLD analysis/6.00 ng L−1 | (62) |
| SBA-15-μSPE | Flavanones/citrus fruits | Citrus edible parts blended; extract filtration; packed 25 mg SBA-15 (1-mL cartridge); preconditioning (1 mL MeOH, 1 mL water); diluted juice (20 μL + 4.97 mL water, pH 7) loading (1 mL min−1 flow rate); washing (1 mL water); vacuum elution (1 mL MeOH); dryness (block heater); resuspension (100 μL MeOH); UHPLC analysis/4.26 ng mL−1 | (45) |
| SBA-15-μSPE | Triterpenoid saponins/TCM | 0.25 g dried powder + 70% EtOH (25 mL); US (ice bath, 30 min); filtration, dilution to 50 mL. SPE: packed 25 mg SBA-15 (1-mL cartridge); preconditioning (1 mL MeOH, 1 mL water); diluted extract loading (1 mL min−1 flow rate); washing (1 mL water); vacuum elution (1 mL EtOH 70%); dryness (N2 stream); resuspension (200 μL MeOH); UHPLC-CAD analysis/0.461-0.976 μg mL−1 | (63) |
| Ni/Co-NO3-LDH-μSPE | Phenolic acids/fruit juices | 2D ultrathin Ni/Co-NO3 layered double hydroxide nanosheet (6.0 mg) added to 5.0 mL sample solution (pH = 7.0); 6 min US; centrifugation at 3,000 rpm for 5.0 min; supernatant decantation; sorbent dissolution in 75 μL TFA (8%, v/v) under US (1.0 min); HPLC analysis (20 μL)/0.1 μg L−1 | (46) |
| MEPS | Furanic derivatives/sugarcane honey | eVol® syringe + RCX sorbent (4 mg); conditioning (250 μL MEOH + 250 μL FA 0.1%); 500 μL sample loading (3 withdraw cycles); 100 μL MeOH washing; 100 μL MeOH: FA 0.1% (95:5, v/v) elution + 100 μL FA 0.1% elution; UHPLC-PDA analysis/30.6-737.7 μg kg−1 | (64) |
| MIP-MEPS | Caffeine/soft & energy drinks | 4 mg MIP; 150 μL sample (pH 4); 200 μL MEOH: acetic acid (9: 1, v/v) elution, one draw-eject cycle/1 μg mL−1 | (65) |
| MEPS, μSPEed | Polyphenols/baby food | MEPS: eVol® syringe (500 μL) + 4 mg DVB/HLB sorbent BIN; 100 μL MeOH + 100 μL FA 0.1% conditioning; 250 μL (pH 2.0) sample loading (10 withdraw cycles, flow rate 20 μL s−1); 100 μL MeOH: FA 0.1% (95:5, v/v) elution; HPLC-PDA analysis. μSPEed: digiVol® syringe + PS/DVB-RP sorbent. 100 μL MeOH + 100 μL FA 0.1% conditioning; 100 μL (pH 2) sample loading (10 withdraw cycles); 50 μL MeOH: FA 0.1% (95:5, v/v) elution; UHPLC-PDA analysis/1.37, 13.57 μg kg−1 | (66) |
| μSPEed | Phenolics/tea | eVol® syringe (200 μL/min flow rate) + PS/DVB-RP sorbent; conditioning (500 μL MeOH + 200 μL FA 0.1%); 2 × 100 μL sample loading; 50 μL MeOH: FA 0.1% (95:5, v/v) elution; UHPLC-PDA analysis (2 μL)/3.5-16.8 ng mL−1 | (67) |
| SE/dSPE | Polyphenols/juice, smoothies | 50 mg of HMS-C18 conditioned with 1 mL MeOH/water (50:50, v/v); 10 min stirring (300 rpm); add 5 mL sample extract, 20 min stirring (300 rpm); filtration (0.45 μm); elution (2 × 3 mL MeOH/water 95:5, v/v pH 2); evaporation to dryness; MeOH resuspension (500 μL); UHPLC-MS analysis/0.01-1.7 μg mL−1 | (68) |
| CNF-NLPNE | Phytohormones, ginsenosides/standard solutions | CNFs/CFs (standard solutions): 1- Conditioning step: US (5 min) of 3000 CNFs/CFs (1 cm length, 10.00 mg) in NCS; 2- solvent loading step: CNFs/CFs soaking NCS (100 μL, 3 s); 3- extraction step: CNFs/CFs dipped in 1 mL (unstirred, stirred, or vortexed solutions); 4- desorption step: CNFs/CFs dipped in NCS (1 mL); US (30 s). Needle-tip device procedure: 1- solvent loading: CNFs/CFs wetted in acidified ACN (10 μL NCS); 2- sampling: needle inserted into the sample; 3- extraction: 25 μL sample juice drawn from fruit and discarded (2.5 μL s−1); 4- Desorption step: 10 μL acidified ACN (FA 1%) drawn (2.5 μL s−1 flow rate); LC-MS/MS analysis/0.01-5.53 ng mL−1 | (69) |
| M-DES-dμSPE/M-dμSPE | Morin, quercetin, kaempferol/foods | Sampling: apple juice (commercial juice extractor) centrifuged (5,000 × g, 15 min), supernatant collected; green tea infusion (0.5 g/100 mL boiling water, 10 min) cooled to RT; dried onion (50°C, 7 h) extraction (1 g/10 mL HCl 25%, 80°C, 30 min); centrifugation (5,000 × g, 10 min), 10 × dilution double distilled deionized water. M-DES-dSPE: 150 μ DES3 + 7 mg of SiO2@Fe3O4 MNPs; US (1 min); 10 mL sample (1 mL glass syringe) + solution, equilibrium in few seconds; magnet to isolate MNPs; elution (250 μL EtOH, 2 min US). HPLC-UV analysis (25 μL). M-dSPE: like DES-dμSPE but not using DES/0.2–2.98 μg L−1 | (48, 70) |
| MSPDM | Phenols/olive fruits | Glass mortar blending (60 s) powdered sample (50 mg) + 25 mg middle-molecular-weight chitosan (dispersant); column packing, plunger compression; elution (3 × 0.5 mL MeOH (60%, v/v); evaporation to dryness; MeOH redissolution (200 μL); centrifugation (5 min, 13,000 rpm), UHPLC-Q-TOF/MS analysis (2 μL)/69.6-358 ng g−1 | (47) |
| Graphene nanoplatelets-MSPDM | Phenolic acids/plant preparations | Graphene nanoplatelets and sample mixture (mortar) packed into 1-mL SPE cartridge; 0.2 mL elution (different solvents); dilution (10 ×, elution solvent); centrifugation (5 min, 13,000 rpm); UHPLC-ECD analysis (2 μL)/1.19–4.62 ng mL−1 | (71) |
| ILs-MSPDM | Neohesperidin, naringin/lime fruit | 50 mg sample powder + 150 mg Florisil dispersant placed into glass mortar and homogenized (1 min); transfer to SPE cartridge (3 mL) with frits in both ends; [Bmin]BF4 (0.4 mL, 250 mM) elution under vacuum (28.0 bar); centrifugation (13,000 rpm, 5 min); UHPLC analysis/4.08, 5.04 μg g−1 | (72) |
| ILs-MSPDM | GA, resveratrol, etc/TCM | Grinding (25 mg sample + 25 mg disorganized silica, 2 min, mortar); SPE packing; 1 mL 150 mM 1-dodecyl-3-methylimidazolium bromide elution; 10 min 14,000 rpm centrifugation; filtration; 2 μL UHPLC analysis | (73) |
| MSPDM | Coumarins, phenolic acids/TCM plants | Grinding (25 mg sample + 25 mg Diol, 3 min, mortar); SPE packing; elution (MeOH 70%); centrifugation (14,000 rpm, 10 min); UHPLC analysis/0.08–0.12 μg mL−1 | (74) |
| MSPDM | Narirutin, naringin, hesperidin, neohesperidin/citrus fruit | 30 mg dispersant + 25 mg sample; 1 min grinding (agate mortar); homogenization; 2.5 mL MeOH, 5 min vortex; eluent diluted 20 × 5 min at 13,000 rpm centrifugation; IM-QTOF-MS analysis/3.70–6.52 ng mL−1 | (75) |
| MOF-MSPDM | Saponins/ginseng leaves | MOF-808 grinding (25 mg leaves, 30 s); glass cartridge packing; 200 μL MeOH elution/0.087-0.114 μg mL−1 | (76) |
| QuEChERS | Trigonelline, caffeine, chlorogenic acid/green coffee beans | 0.200 g powdered coffee beans; 10 mL 1% acetic acid; 90 min US (RT); 1,700 g centrifugation; decantation; 50 μL coffee extract diluted to 4 ml (1% acetic acid); 4 mL ACN; mix; 0.5 g NaCl + 1.0 g MgSO4; vigorous shaking; centrifugation; ACN phase (upper) analyzed by UV-VIS (50 μl diluted to 4 ml); aqueous phase (lower) extracted twice with ACN; UV-VIS analysis/1.51, 0.960, 0.879 mg L−1 | (77) |
| μQuEChERS | Polyphenols/baby food | 0.3 g sample (2 mL tube) + 0.2 g μQuEChERS mixture (buffered salts, 4:1:1:0.5) + acidified (0.1% FA) ACN:EtAc (1 mL, 1:1, v/v); vortex (10 s) + US extraction (5 min); centrifugation (5 min, 5,000 rpm); 700 μL supernatant transferred to 2 mL PTFE dSPE tube (75 mg MgSO4 + 12.5 mg PSA); vortex (30 s); centrifuge (5 min, 4,000 rpm); filtration (500 μL extract, 0.22 μm PTFE filter); evaporation to dryness; MeOH reconstitution (100 μL); UHPLC-PDA analysis/0.04–0.46 μg g−1 | (50) |
| SALLE | Naringenin/fruit juices | 5 mL samples + 1.7 mL ACN; 30 s vortex; 1 g (NH4)2SO4, 5 min shaken; 5 min 9,000 rpm centrifugation; 500 μL upper phase evaporated; 500 μL MeOH reconstitution; HPLC analysis/0.1 μg mL−1 | (78) |
| SALLE | Isoflavones/soy milk | 2.5 g samples (pH 6) + NaCl + ACN; 300 rpm shaking; 5 min 3,000 rpm centrifugation (25 ± 4°C); ACN phase filtration; UHPLC–MS/MS analysis/1–30 pg | (79) |
| SALLE | Matrine alkaloids/TCM | 200 μL sample + 8 mL 10% NaCl (pH 12); 120 μL CHCl3 injected rapidly; 30 s mix, 3 min rest; CHCl3 volatilized naturally; MeOH reconstitution; 20 μL HPLC analysis/0.06, 0.08 ng mL−1 | (80) |
ACN, acetonitrile; BIN, barrel insert needle; [Bmin]BF4, 1-butyl-3-methylimidazolium tetrafluoroborate; CNFs, carbon nanofibers; CNTs, carbon nanotubes; DES, deep eutectic solvents; dSPE, dispersive solid-phase extraction; DVB, divinylbenzene; ECD, electrochemical detection; EPT-SPME, effervescent pipette tip solid phase microextraction; EtOH, ethanol; FA, formic acid; FGO-TD-PTFE, functional graphene oxide thermal desorption poly(tetrafluoroethylene); FLD, fluorescence detector; GA, gallic acid; GC-MS, gas chromatography-mass spectrometry; HAc, acetic acid; HLB, hydrophilic-lipophilic-balanced; HS, headspace; ILs, ionic liquids; LDH, layered double hydroxide; M-SPE, magnetic solid-phase extraction; MIP, molecular imprinted polymer; MIOMS-ir, molecularly imprinted ordered mesoporous silica imprint-removed silica; MISM, molecularly imprinted silica monolithic; ME, microextraction; MeOH, methanol; MEPS, microextraction by packed sorbent; MMF, multiple monolithic fiber; MNPs, magnetic nanoparticles; MOF, Metal–organic framework; MSPDM, matrix solid-phase dispersion microextraction; MWCNTs, Multi-walled CNTs; NCS, nanoconfined solvent; NTD, needle trap device; NTME, needle-trap microextraction; PDA, photodiode array; PDMS, polydimethylsiloxane; PS/DVB-RP, reverse phase polystyrene-divinylbenzene sorbent; PT- pipette tip; RAMIPs, restricted access molecularly imprinted polymers; RT, room temperature; SALLE, salting-out liquid-liquid extraction; SBA-15, Santa Barbara Amorphous 15 molecular sieve; SPME, solid-phase microextraction; TCM, traditional Chinese medicine; US, ultrasonication; VOCs, volatile organic compounds; UHPLC, ultrahigh performance liquid chromatography; UV, ultraviolet analysis; μSPE, micro solid-phase extraction.