1. Introduction

The contact surface area between the donor (sampNote：Alle) and the acceptor (extractant) is a critical variable in the context of microextraction techniques ^[1]. The efficieinformation int dispersion of the extractant phase into the sample in the form of a fine suspension of micro/nano particles or drops is the most common approach to enhance the close contact between phases ^[2]. Several strategies, both in the solithis draft can be ed-phase and liquid-phase microextraction contexts, have been proposed. These strategies can be generally divided into two main groups depending on the use of a external energy source ^[3][4] or chemicals ^[5][6] ted by authors. And to achieve this dispersion.

In 2011, a new dispersion se entrategy was proposed by Lasarte-Aragonés et al. ^[7] and, sill be onlince then, it has been developed and applied by many different groups worldwide. The technique is based on the in situ gene only afteration of carbon dioxide because of the reaction between a carbon dioxide donor and a proton donor in the so-called effervescent reaction. The CO₂ bubbles generateauthors edit and produces an efficient dispersion of the extractant phase into the sample. The technique has been successfully applied to the solid-phase and liquid-phase microextraction contexts, as a green, cheap, and simple alternativeubmit it.

1.Introduction

The contact surface area between the donor (sample) and the acceptor (extractant) is a critical variable in the context of microextraction techniques [1]. The efficient dispersion of the extractant phase into the sample in the form of a fine suspension of micro/nano particles or drops is the most common approach to enhance the close contact between phases [2]. Several strategies, both in the solid-phase and liquid-phase microextraction contexts, have been proposed. These strategies can be generally divided into two main groups depending on the use of a external energy source [3,4] or chemicals [5,6] to achieve this dispersion.

In 2011, a new dispersion strategy was proposed by Lasarte-Aragonés et al. [7] and, since then, it has been developed and applied by many different groups worldwide. The technique is based on the in situ generation of carbon dioxide because of the reaction between a carbon dioxide donor and a proton donor in the so-called effervescent reaction. The CO₂ bubbles generated produces an efficient dispersion of the extractant phase into the sample. The technique has been successfully applied to the solid-phase and liquid-phase microextraction contexts, as a green, cheap, and simple alternative.

2. Effervescence-Assisted Dispersive Micro-Solid Phase Extraction

Dispersive solid phase extraction (DSPE) is based on the dispersion of a solid sorbent into the sample of interest proposed by Anastassiades [8] as clean-up method aimed to remove interferences from the matrix, aided by vortex agitation. This kind of cleanup strategy later received the name of QuEChERS, an acronym for its advantages: quick, easy, cheap, effective, rugged, and safe and is now commercially available as a sample treatment strategy [9].

The miniaturized version is usually named dispersive micro-solid phase extraction (DµSPE). The cornerstone of DµSPE is the dispersion of the sorbent (extractant phase) in the sample. The process must take into consideration the nature and properties of the sorbent (polarity, micro or nano-size, aggregation) and can be achieved by physical or chemical means. Physical dispersion is typically assisted by an external energy source such as ultrasound irradiation [10] or vortex agitation [11]. Chemical dispersion is aimed to improve dispersibility by using a water-miscible organic solvent such as acetonitrile or methanol [12].

The first effervescent-based approach for this alternative is based on the fabrication of a tablet containing a commercial sorbent (OASIS-HLB) and reaction precursors (sodium carbonate as CO

₂

source and sodium dihydrogen phosphate as proton donor) [7]. The tablet containing all the elements was then introduced into the aqueous sample, and the sorbent is effectively dispersed by the in situ-generated gas bubbles. The alternative is designed to provide all the elements to perform the extraction process on-site, avoiding the use of a disperser solvent (minimizing environmental impact and waste generation) or external apparatus (such as vortex or ultrasounds). In fact, the first implementation of the technique employs a syringe as both sample-collection and extraction vessel device. The effervescent sorbent tablet is placed inside the syringe and the extraction process starts once the sample is aspirated. The dispersed sorbent can be easily recovered by a syringe filter and eluted before analysis. The method was employed for the determination of nitroaromatic compounds in water samples. Its analytical performance was comparable to other SPE alternatives for the same analytical problem, but in a simpler and rapid fashion. Analyte partition equilibrium is not affected by the effervescence process, and different sorbents can be used according to the target analytes.

The potential of effervescent tablets was later demonstrated in the effective dispersion of a nanometric sorbent, multiwalled carbon nanotubes (MWCNTs), in aqueous matrices [13], which are known for their limited dispersibility due to their trend to aggregation. The use of effervescent tablet (102 mm ID) was responsible for the efficient dispersion of the unmodified sorbent, resulting in more effective than mechanical agitation. By this means, a small amount of sorbent (7.5 mg) can be successfully dispersed in a large sample volume (100 mL) without the assistance of any external apparatus or energy source. The proposed alternative combined with Liquid Chromatography-Diode Array Detector (LC-DAD)

3. Effervescence-Assisted Dispersive Liquid-Phase Microextraction

Dispersive liquid–liquid extraction (DLLME), proposed by Rezaee et al. in 2006, is based on the efficient dispersion of an extractant solvent into the sample ^[14]. In the typical approach, this dispersion is aided by a disperser solvent that is miscible with both the sample and the extractant phase, which is recovered by centrifugation. The use of an organic solvent as the disperser has two main shortcomings. On the one hand, the volume of disperser solvent is in the mL range, and, therefore, DLLME cannot be completely considered a microextraction technique. On the other hand, the disperser solvent is mixed with the aqueous sample, increasing the analytes’ solubility in the donor phase, reducing its transfer to the extractant phase. The need for a disperser solvent can be reduced if an external energy source, like US ^[36] and vortex ^[5], is used.

Dispersive liquid–liquid extraction (DLLME), proposed by Rezaee et al. in 2006, is based on the efficient dispersion of an extractant solvent into the sample [14]. In the typical approach, this dispersion is aided by a disperser solvent that is miscible with both the sample and the extractant phase, which is recovered by centrifugation. The use of an organic solvent as the disperser has two main shortcomings. On the one hand, the volume of disperser solvent is in the mL range, and, therefore, DLLME cannot be completely considered a microextraction technique. On the other hand, the disperser solvent is mixed with the aqueous sample, increasing the analytes’ solubility in the donor phase, reducing its transfer to the extractant phase. The need for a disperser solvent can be reduced if an external energy source, like US [36] and vortex [5], is used.

Lasarte-Aragones et al. proposed the adaptation of effervescence extraction to the LPME context in 2014 [15]. Effervescence-assisted DLLME (EA-DLLME) consists of the in situ production of carbon dioxide due to the reaction of sodium carbonate (previously added to the sample) and the disperser solvent (acetic acid), which also contains the extractant phased. The reaction also generates sodium acetate that contributes to the ionic strength and may produce a salting-out effect. In this preliminary work, magnetic nanoparticles were added to the acetic acid-extractant mixture and used to recover the extractant from the sample avoiding the centrifugation process. The extractant solvent, 1-octanol, is recovered by the interaction of the alcohol group with residual hydroxyl groups on the surface of the nanoparticles.

Lasarte-Aragones et al. proposed the adaptation of effervescence extraction to the LPME context in 2014 ^[15]. Effervescence-assisted DLLME (EA-DLLME) consists of the in situ production of carbon dioxide due to the reaction of sodium carbonate (previously added to the sample) and the disperser solvent (acetic acid), which also contains the extractant phased. The reaction also generates sodium acetate that contributes to the ionic strength and may produce a salting-out effect. In this preliminary work, magnetic nanoparticles were added to the acetic acid-extractant mixture and used to recover the extractant from the sample avoiding the centrifugation process. The extractant solvent, 1-octanol, is recovered by the interaction of the alcohol group with residual hydroxyl groups on the surface of the nanoparticles.

4. Developments of Effervescence-assisted microextraction

Since its introduction, many researchers have expanded the applications of the concept to a variety of sorbents and solvents in different matrices, demonstrating the wide range of applicability of the technique. A detailed and complete review of these methodologies can be found in the recent publication by our research group ^[16]. The main contributions to the technique are presented in Table 1.

Since its introduction, many researchers have expanded the applications of the concept to a variety of sorbents and solvents in different matrices, demonstrating the wide range of applicability of the technique. A detailed and complete review of these methodologies can be found in the recent publication by our research group [16]. The main contributions to the technique are presented in Table 1.

Table 1. Applications based on the use of effervescence-assisted microextraction.

Applications based on the use of effervescence-assisted microextraction.

1. ,
2. 156
3. , 104837.

References

1. Cruz-Vera, M.; Lucena, R.; Cárdenas, S.; Valcárcel, M. Sample treatments based on dispersive (micro)extraction. Anal. Methods 2011, 3, 1719.
2. Chisvert, A.; Cárdenas, S.; Lucena, R. Dispersive micro-solid phase extraction. TrAC Trends Anal. Chem. 2019, 112, 226–233.
3. Psillakis, E. Vortex-assisted liquid-liquid microextraction revisited. TrAC Trends Anal. Chem. 2019, 113, 332–339.
4. Ojeda, C.B.; Rojas, F.S. Vortex-Assisted Liquid–Liquid Microextraction (VALLME): The Latest Applications. Chromatographia 2018, 81, 89–103.
5. Kocúrová, L.; Balogh, I.S.; Šandrejová, J.; Andruch, V. Recent advances in dispersive liquid–liquid microextraction using organic solvents lighter than water. A review. Microchem. J. 2012, 102, 11–17.
6. Dmitrienko, S.G.; Apyari, V. V.; Tolmacheva, V. V.; Gorbunova, M. V. Dispersive Liquid–Liquid Microextraction of Organic Compounds: An Overview of Reviews. J. Anal. Chem. 2020, 75, 1237–1251.
7. Lasarte-Aragonés, G.; Lucena, R.; Cárdenas, S.; Valcárcel, M. Effervescence-assisted dispersive micro-solid phase extraction. J. Chromatogr. A 2011, 1218.
8. Anastassiades, M.; Lehotay, S.J.; Štajnbaher, D.; Schenck, F.J. Fast and Easy Multiresidue Method Employing Acetonitrile Extraction/Partitioning and “Dispersive Solid-Phase Extraction” for the Determination of Pesticide Residues in Produce. J. AOAC Int. 2003, 86, 412–431.
9. Perestrelo, R.; Silva, P.; Porto-Figueira, P.; Pereira, J.A.M.; Silva, C.; Medina, S.; Câmara, J.S. QuEChERS - Fundamentals, relevant improvements, applications and future trends. Anal. Chim. Acta 2019, 1070, 1–28.
10. Asfaram, A.; Ghaedi, M.; Goudarzi, A. Optimization of ultrasound-assisted dispersive solid-phase microextraction based on nanoparticles followed by spectrophotometry for the simultaneous determination of dyes using experimental design. Ultrason. Sonochem. 2016, 32, 407–417.
11. Jiménez-Soto, J.M.; Cárdenas, S.; Valcárcel, M. Dispersive micro solid-phase extraction of triazines from waters using oxidized single-walled carbon nanohorns as sorbent. J. Chromatogr. A 2012, 1245, 17–23.
12. Aladaghlo, Z.; Fakhari, A.; Behbahani, M. Solvent-assisted dispersive solid-phase extraction: A sample preparation method for trace detection of diazinon in urine and environmental water samples. J. Chromatogr. A 2016, 1462, 27–34.
13. Lasarte-Aragonés, G.; Lucena, R.; Cárdenas, S.; Valcárcel, M. Effervescence-assisted carbon nanotubes dispersion for the micro-solid-phase extraction of triazine herbicides from environmental waters. Anal. Bioanal. Chem. 2013, 405.
14. Rezaee, M.; Assadi, Y.; Milani Hosseini, M.-R.; Aghaee, E.; Ahmadi, F.; Berijani, S. Determination of organic compounds in water using dispersive liquid–liquid microextraction. J. Chromatogr. A 2006, 1116, 1–9.
15. Lasarte-Aragonés, G.; Lucena, R.; Cárdenas, S.; Valcárcel, M. Effervescence assisted dispersive liquid–liquid microextraction with extractant removal by magnetic nanoparticles. Anal. Chim. Acta 2014, 807, 61–66.
16. Lasarte-Aragonés, G.; Lucena, R.; Cárdenas, S. Effervescence-Assisted Microextraction—One Decade of Developments. Mol. 2020, 25.
17. Wang, S.-L.; Pang, X.-Q.; Cao, J.; Cao, W.; Xu, J.-J.; Zhu, Q.-Y.; Zhang, Q.-Y.; Peng, L.-Q. Effervescence and graphitized multi-walled carbon nanotubes assisted microextraction for natural antioxidants by ultra high performance liquid chromatography with electrochemical detection and quadrupole time-of-flight tandem mass spectrometry. J. Chromatogr. A 2015, 1418, 12–20.
18. Ye, L.-H.; Cao, W.; Hu, S.-S.; Da, J.-H.; Dai, H.-B.; Cao, J.; Xu, J.-J.; Pang, X.-Q. Effervescent-salt-assisted dispersive micro-solid-phase extraction using mesoporous hybrid materials coupled with ultra-performance liquid chromatography for the determination of trace-level compounds in complicated plant preparations. Anal. Bioanal. Chem. 2015, 407, 1763–1773.
19. Yang, X.; Zhang, P.; Li, X.; Hu, L.; Gao, H.; Zhang, S.; Zhou, W.; Lu, R. Effervescence-assisted β-cyclodextrin/attapulgite composite for the in-syringe dispersive solid-phase extraction of pyrethroids in environmental water samples. Talanta 2016, 153, 353–359.
20. Yang, X.; Mi, Y.; Liu, F.; Li, J.; Gao, H.; Zhang, S.; Zhou, W.; Lu, R. Preparation of magnetic attapulgite/polypyrrole nanocomposites for magnetic effervescence-assisted dispersive solid-phase extraction of pyrethroids from honey samples. J. Sep. Sci. 2020, 43, 2419–2428.
21. Wu, X.; Yang, M.; Zeng, H.; Xi, X.; Zhang, S.; Lu, R.; Gao, H.; Zhou, W. Effervescence-assisted dispersive solid-phase extraction using ionic-liquid-modified magnetic β-cyclodextrin/attapulgite coupled with high-performance liquid chromatography for fungicide detection in honey and juice. J. Sep. Sci. 2016, 39, 4422–4428.
22. Zhou, P.; Zheng, R.; Zhang, W.; Liu, W.; Li, Y.; Wang, H.; Wang, X. Development of an effervescent tablet microextraction method using NiFe2O4-based magnetic nanoparticles for preconcentration/extraction of heavy metals prior to ICP-MS analysis of seafood. J. Anal. At. Spectrom. 2019, 34, 598–606.
23. Fahimirad, B.; Rangraz, Y.; Elhampour, A.; Nemati, F. Diphenyl diselenide grafted onto a Fe3O4-chitosan composite as a new nanosorbent for separation of metal ions by effervescent salt-assisted dispersive magnetic micro solid-phase extraction. Microchim. Acta 2018, 185, 1–8.
24. Karbalaie, B.; Rajabi, M.; Fahimirad, B. Dopamine-modified magnetic graphene oxide as a recoverable sorbent for the preconcentration of metal ions by an effervescence-assisted dispersive micro solid-phase extraction procedure. Anal. Methods 2020, 12, 2338–2346.
25. Karbalaie, B.; Rajabi, M.; Fahimirad, B. Polymerisation of dopamine on the carbon graphite nitride nanosheets as an effective adsorbent in determination of metal ions using effervescent-assisted dispersive micro solid-phase extraction method. Int. J. Environ. Anal. Chem. 2020, 1–19.
26. Fahimirad, B.; Rajabi, M.; Elhampour, A. A rapid and simple extraction of anti-depressant drugs by effervescent salt-assisted dispersive magnetic micro solid-phase extraction method using new adsorbent Fe3O4@SiO2@N3. Anal. Chim. Acta 2019, 1047, 275–284.
27. Ding, W.; Wang, X.; Liu, T.; Gao, M.; Qian, F.; Gu, H.; Zhang, Z. Preconcentration/extraction of trace bisphenols in milks using a novel effervescent reaction-assisted dispersive solid-phase extraction based on magnetic nickel-based N-doped graphene tubes. Microchem. J. 2019, 150, 104109.
28. Tan, C.; Li, J.; Liu, W.; Zhao, Q.; Wang, X.; Li, Y. Core-shell magnetic covalent organic framework nanocomposites as an adsorbent for effervescent reaction-enhanced microextraction of endocrine disruptors in liquid matrices. Chem. Eng. J. 2020, 396, 125191.
29. Hu, Y.-H.; Wang, Q.-Y.; Ye, L.-H.; Yang, J.; Dong, X.; Zheng, H.; Zhou, J.; Cao, J. Effervescent salt and crown ether-assisted matrix solid-phase dispersion extraction of coumarins from Cortex fraxini. Ind. Crops Prod. 2019, 141, 111752.
30. Wang, N.; Xin, H.; Zhang, Q.; Jiang, Y.; Wang, X.; Shou, D.; Qin, L. Carbon nanotube-polymer composite for effervescent pipette tip solid phase microextraction of alkaloids and flavonoids from Epimedii herba in biological samples. Talanta 2017, 162, 10–18.
31. Jamshidi, S.; Rofouei, M.K.; Thorsen, G. Using magnetic core-shell nanoparticles coated with an ionic liquid dispersion assisted by effervescence powder for the micro-solid-phase extraction of four beta blockers from human plasma by ultra high performance liquid chromatography with mass spectro. J. Sep. Sci. 2019, 42, 698–705.
32. Hu, L.; Qian, H.; Yang, X.; Li, S.; Zhang, S.; Lu, R.; Zhou, W.; Gao, H. Effervescence-assisted dispersive liquid–liquid microextraction based on the solidification of a floating ionic liquid with a special collection method for the rapid determination of benzoylurea insecticides in water samples. RSC Adv. 2016, 6, 95283–95291.
33. Wu, X.; Li, X.; Yang, M.; Zeng, H.; Zhang, S.; Lu, R.; Gao, H.; Xu, D. An ionic liquid-based nanofluid of titanium dioxide nanoparticles for effervescence-assisted dispersive liquid–liquid extraction for acaricide detection. J. Chromatogr. A 2017, 1497, 1–8.
34. Wang, X.; Wu, L.; Cao, J.; Hong, X.; Ye, R.; Chen, W.; Yuan, T. Magnetic effervescent tablet-assisted ionic liquid dispersive liquid–liquid microextraction of selenium for speciation in foods and beverages. Food Addit. Contam. Part A 2016, 33, 1190–1199.
35. Yang, M.; Wu, X.; Jia, Y.; Xi, X.; Yang, X.; Lu, R.; Zhang, S.; Gao, H.; Zhou, W. Use of magnetic effervescent tablet-assisted ionic liquid dispersive liquid–liquid microextraction to extract fungicides from environmental waters with the aid of experimental design methodology. Anal. Chim. Acta 2016, 906, 118–127.
36. Li, Y.; Hu, J.; Liu, W.; Jin, L.; Zhou, P.; Zhang, Y.; Zhang, B.; Dahlgren, R.A.; Wang, X.; Zhou, Y. Magnetic effervescent tablet-assisted ionic liquid-based dispersive liquid-liquid microextraction of polybrominated diphenyl ethers in liquid matrix samples. Talanta 2019, 195, 785–795.
37. Wu, J.; Xu, Z.; Pan, Y.; Shi, Y.; Bao, X.; Li, J.; Tong, Y.; Tang, H.; Ma, S.; Wang, X.; et al. Combination of in situ metathesis reaction with a novel “magnetic effervescent tablet-assisted ionic liquid dispersive microextraction” for the determination of endogenous steroids in human fluids. Anal. Bioanal. Chem. 2018, 410, 2921–2935.
38. Zhang, W.; Zhou, P.; Liu, W.; Wang, H.; Wang, X. Enhanced adsorption/extraction of five typical polycyclic aromatic hydrocarbons from meat samples using magnetic effervescent tablets composed of dicationic ionic liquids and NiFe2O4 nanoparticles. J. Mol. Liq. 2020, 315, 113682.
39. Zhou, P.; Chen, K.; Gao, M.; Qu, J.; Zhang, Z.; Dahlgren, R.A.; Li, Y.; Liu, W.; Huang, H.; Wang, X. Magnetic effervescent tablets containing ionic liquids as a non-conventional extraction and dispersive agent for determination of pyrethroids in milk. Food Chem. 2018, 268, 468–475.
40. Piao, H.; Jiang, Y.; Qin, Z.; Tao, S.; Ma, P.; Sun, Y.; Wang, X.; Song, D. Development of a novel acidic task-specific ionic liquid-based effervescence-assisted microextraction method for determination of triazine herbicides in tea beverage. Talanta 2020, 208, 120414.
41. Wang, X.; Xu, G.; Guo, X.; Chen, X.; Duan, J.; Gao, Z.; Zheng, B.; Shen, Q. Effervescent tablets containing magnetic ionic liquids as a non-conventional extraction and dispersive agent for speciation of arsenite and arsenate in vegetable samples. J. Mol. Liq. 2018, 272, 871–877.
42. Shishov, A.; Sviridov, I.; Timofeeva, I.; Chibisova, N.; Moskvin, L.; Bulatov, A. An effervescence tablet-assisted switchable solvent-based microextraction: On-site preconcentration of steroid hormones in water samples followed by HPLC-UV determination. J. Mol. Liq. 2017, 247, 246–253.
43. Gao, M.; Wang, J.; Song, X.; He, X.; Dahlgren, R.A.; Zhang, Z.; Ru, S.; Wang, X. An effervescence-assisted switchable fatty acid-based microextraction with solidification of floating organic droplet for determination of fluoroquinolones and tetracyclines in seawater, sediment, and seafood. Anal. Bioanal. Chem. 2018, 410, 2671–2687.
44. Hemmati, M.; Rajabi, M. Switchable fatty acid based CO2-effervescence ameliorated emulsification microextraction prior to high performance liquid chromatography for efficient analyses of toxic azo dyes in foodstuffs. Food Chem. 2019, 286, 185–190.
45. Jing, X.; He, J.; Zhao, W.; Huang, X.; Wang, X. Effervescent tablet-assisted switchable hydrophilicity solvent-based microextraction with solidification of floating organic droplets for HPLC determination of phenolic endocrine disrupting chemicals in bottled beverages. Microchem. J. 2020, 155, 104680.
46. Jing, X.; Cheng, X.; Zhao, W.; Wang, H.; Wang, X. Magnetic effervescence tablet-assisted switchable hydrophilicity solvent-based liquid phase microextraction of triazine herbicides in water samples. J. Mol. Liq. 2020, 306, 112934.
47. Ghorbani Ravandi, M.; Fat’hi, M.R. Green effervescence assisted dispersive liquid–liquid microextraction based on a hydrophobic deep eutectic solvent for determination of Sunset Yellow and Brilliant Blue FCF in food samples. New J. Chem. 2018, 42, 14901–14908.
48. Arpa, Ç.; Albayati, S.; Yahya, M. Effervescence-assisted dispersive liquid-liquid microextraction based on deep eutectic solvent for preconcentration and FAAS determination of copper in aqueous samples. Int. J. Environ. Anal. Chem. 2018, 98, 938–953.
49. Zhao, W.; Jing, X.; Tian, Y.; Feng, C. Magnetic Fe3O4 @ porous activated carbon effervescent tablet-assisted deep eutectic solvent-based dispersive liquid–liquid microextraction of phenolic endocrine disrupting chemicals in environmental water. Microchem. J. 2020, 159, 105416.
50. Jia, L.; Huang, X.; Zhao, W.; Wang, H.; Jing, X. An effervescence tablet-assisted microextraction based on the solidification of deep eutectic solvents for the determination of strobilurin fungicides in water, juice, wine, and vinegar samples by HPLC. Food Chem. 2020, 317, 126424.
51. Shishov, A.; Gerasimov, A.; Nechaeva, D.; Volodina, N.; Bessonova, E.; Bulatov, A. An effervescence-assisted dispersive liquid–liquid microextraction based on deep eutectic solvent decomposition: Determination of ketoprofen and diclofenac in liver. Microchem. J. 2020