Submitted Successfully!
To reward your contribution, here is a gift for you: A free trial for our video production service.
Thank you for your contribution! You can also upload a video entry or images related to this topic.
Version Summary Created by Modification Content Size Created at Operation
1
Agnieszka Królicka
 + 1194 word(s) 1194 2022-01-17 07:24:15 |
2 format correct
Bruce Ren
-5 word(s) 1189 2022-02-17 01:47:58 | |
3 format correct
Bruce Ren
-41 word(s) 1153 2022-02-17 01:49:15 |

Video Upload Options

Do you have a full video?
Send video materials Upload full video

Confirm

Are you sure to Delete?
Yes No
Cite
If you have any further questions, please contact Encyclopedia Editorial Office.
Królicka, A. Catalytic Adsorptive Stripping Voltammetric Determination of Germanium. Encyclopedia. Available online: https://encyclopedia.pub/entry/19525 (accessed on 26 April 2024).
Królicka A. Catalytic Adsorptive Stripping Voltammetric Determination of Germanium. Encyclopedia. Available at: https://encyclopedia.pub/entry/19525. Accessed April 26, 2024.
Królicka, Agnieszka. "Catalytic Adsorptive Stripping Voltammetric Determination of Germanium" Encyclopedia, https://encyclopedia.pub/entry/19525 (accessed April 26, 2024).
Królicka, A. (2022, February 16). Catalytic Adsorptive Stripping Voltammetric Determination of Germanium. In Encyclopedia. https://encyclopedia.pub/entry/19525
Królicka, Agnieszka. "Catalytic Adsorptive Stripping Voltammetric Determination of Germanium." Encyclopedia. Web. 16 February, 2022.
Catalytic Adsorptive Stripping Voltammetric Determination of Germanium
Edit
This entry is adapted from the peer-reviewed paper 10.3390/chemosensors10010036

In organic free aqueous solutions, germanium is present in the form of Ge(OH)4 tetrahydroxide (pH < 7) or as H3GeO4−, which dominates in alkaline media (pH > 9). In the presence of many ligands containing carboxylic, di-orthophenolic, and polyalcoholic functional groups, Ge(IV) forms stable five-membered ring chelate complexes displaying coordination number 6.

vanadium germanium aminopolycarboxylic complexes catalytic adsorptive stripping voltammetry HEDTA

1. Adsorptive Stripping Voltammetric Determination of Germanium

When only two organic ligands coordinate Ge(IV), the remaining coordination sites are occupied by water molecules [1]. The water molecules can be easily replaced by other ligands and mixed complexes can be formed. Germanium complexes of different 1,2-diphenol derivatives have been used since the 1990s to determine Ge(IV) traces by means of adsorptive stripping voltammetry (AdSV) because of their ability to accumulate on the surface of the working electrode. The AdSV procedures mainly use catechol [2][3][4][5][6][7], but there are also articles describing how other complexes can also be used to determine trace levels of germanium [8][9][10][11][12][13]. Various electrode reaction schemes have been suggested, but there is no general consensus on the composition and stoichiometry of electroactive complexes [5][6][14] and the nature of products produced by electroreduction processes [5][6][15][16][17][18].
When it comes to practical applications, AdSV procedures for the determination of germanium(IV) allow Ge(IV) to be determined at levels of several nanomol per liter [3][5][12]. However, because of the extremely low germanium content in certain samples, a catalytic approach, namely catalytic adsorptive stripping voltammetry (CAdSV) that would provide considerably greater sensitivity would be desirable.

2. Catalytic Amplification of Germanium Voltammetric Signals in the Presence of Oxoacid Anions

Anions such as BrO3− are among the catalytic agents most widely used for the amplification of voltammetric signals of Ge(IV)-catechol and Ge(IV)-pyrogallol complexes (Table 1). As in the case of AdSV procedures for Ge(IV) determination, several schemes were proposed to describe the catalytic reactions induced by some germanium complexes with ligands containing the -C-(OH)-C-(OH) group (e.g., catechol, gallic acid, pyrogallol) in the presence of various oxidants [15][16][17][19][20]. These schemes were based on the assumption that the catalytic reaction involves a simple regeneration of the product of electroreduction, namely the Ge(IV)-catechol complex.
Table 1. Catalytic systems involving germanium and their properties.
Ligand Catalytic Agent Supporting
Electrolyte		 Electrode P2/P1 1 Linear Range nM LOD nM References
Chemosensors 10 00036 i001
Benzene-1,2-diol
catechol		 BrO3− Acetate buffer DME 2.2 1–7000 1 [15]
VO2+ HClO4, NaClO4 HMDE 11 n.a. n.a. [19]
BrO3− Acetate buffer HMDE 24 n.a. n.a. [20]
V(IV)-EDTA Acetate buffer HMDE 3.5 n.a. n.a. [20]
V(IV)-HEDTA Acetate buffer HMDE 26 0.05–20 0.01 [20]
V(IV)-HEDTA Acetate buffer Hg(Ag)FE n. a. 0.01 0.15 [20]
V(IV)-HEDTA Acetate buffer BiFE/GC n. a. 1.5–24 1.0 [21]
V(IV)-HEDTA Acetate buffer BiFE/SPE n. a. 1.5–19.5 1.0 [21]
V(IV)-HEDTA Acetate buffer BiFE/SPEmeso n. a. 5.0–70 1.2 [21]
Chemosensors 10 00036 i002
Benzene-1,2,3-triol
Pyrogallol		 BrO3− Acetate buffer, trisodium
citrate		 BiFE/GC 1.5 7–230 0.8 [16]
V(IV)-HEDTA Acetate buffer HMDE 100 0.25–25 0.02 [22]
V(IV)-EDTA Acetate buffer HMDE 10 n.a. n.a. [22]
V(IV)-NTA Acetate buffer HMDE 1.5 n.a. n.a. [22]
Chemosensors 10 00036 i003
3,4,5-Trihydroxybenzoic acid, gallic acid		 V(IV)-EDTA HClO4 HMDE n.a. 0.03–10 0.02 [17]
V(IV)-EDTA H2SO4 DME 10 0.55–275 0.05 [18]
Chemosensors 10 00036 i004
2,5-Dichloro-3,6-dihydroxycyclohexa-2,5-diene-1,4-dione, chloranilic acid		 V(IV)-HEDTA Acetic acid HMDE 21 0.75–50 0.085 [23]
V(IV)-HEDTA Acetic acid Hg(Ag)FE 12 1–25 0.7 [23]
Chemosensors 10 00036 i005
3,4-Dihydroxybenzaldehyde (DHB)		 V(IV)-EDTA KCl HMDE 17 0.1–10 0.05 [24]

 

Catechin

V(IV)-HEDTA Acetate buffer HMDE n.a. 40-480 n.a. [25]

Alizarin sodium monosulfonate

 V(IV)-HEDTA Acetate buffer HMDE n.a. 40-440 n.a. [25]

Alizarin complexone

 V(IV)-HEDTA Acetate buffer HMDE n.a. 40-1200 n.a. [25]

3. Catalytic Amplification of Germanium Voltammetric Signals by Aminopolycarboxylic Acid Complexes with V(IV)

The Ge(IV) can be also efficiently amplified by complexes of V(IV) with aminopolycarboxylic acids such as EDTA, HEDTA and NTA. The ratio of the peak current obtained when the catalytic systems are used to the peak current obtained for the AdSV system in the absence of any oxidant ranges from several to several dozens. The amplification factor (PCAdSV/PAdSV) depends on many parameters, primarily on the type of V(IV) complex and the ligand that form complexes with Ge(IV), but also on the type of the working electrode, the supporting electrolyte composition, and, finally the instrumental parameters.
The characteristic features of the cyclic voltammograms obtained for the catalytic systems of Ge(IV) employing aminopolycarboxylic acid complexes of V(IV) are highlighted in Figure 1.

Figure 1. CV voltammogram of the Ge(IV) catalytic system and its characteristic features.

Part 1 of the CV voltammogram represents the region of the reduction-oxidation of the V(IV) complex. A vanadium complex that undergoes a more electrochemically reversible reduction can amplify the germanium signal to a greater extent than one that is reduced irreversibly. The catalytic activity of the three reported ligands can be ranked as follows: HEDTA > EDTA > NTA. The region labeled 2 represents the catalytically amplified signal of germanium. The peak potential of the Ge(IV) signal depends on the ligand type and the material of the working electrode. It is localized between -0.55 V and -0.65 V for the HMDE and Hg(Ag)FE electrodes. When BiFE electrodes are used, the Ge(IV) peak appears at slightly more negative potentials namely, between -0.7 V and -0.8 V. Additionally, both the negative-going and positive-going branches of CV runs show cathodic signals, which confirms the catalytic nature of the electrode process. The cathodic peak observed at backward running is clearly visible on the magnified part of section 2. Such a CV curve implies that the investigated catalytic systems may be attributed to catalytic systems of the second kind [26]. Under this assumption, the electroreduction of adsorbed Ge(IV)-catechol produces a very active Ge(II)-catechol complex [GeII(OH)2L2]4- (Scheme 1), which forms a composite complex with V(IV)-HEDTA denoted as [GeII(OH)2L2]-[VIVO(HY)] (Scheme 1). In this composite complex, vanadium(IV) undergoes reduction to vanadium(II), which results in the breakdown of the multi-component complex. The regenerated germanium catecholate complex [GeII(OH)2L2]4-retains its activity and combines with additional V(IV)-HEDTA ion. In this way, the catalytic cycle forms, indicated by an arrow in Scheme 1. The number of electrons per germanium ion exchanged during electroreduction increases significantly, which contributes to a substantial rise in the current of the recorded germanium peaks, and thus to an increase in the sensitivity of the analytical procedure.

Scheme 1. Catalytic reactions responsible for the amplification of the Ge(IV) voltammetric signal.

The section labeled 3 presents the range of potentials that can be applied for the adsorptive accumulation of the Ge(IV) complex. On the positive side of potentials, this range is limited by the oxidation process of the electrode material. In the case of the bismuth electrode, this range is narrower than that for the mercury electrode, because the bismuth oxidation process is already noticeable at potentials more positive than -0.4 V.

To apply the catalytic system for the determination of Ge(IV), an extensive optimization study should be undertaken on the influence of chemical and instrumental variables.

References

  1. Gleb S. Pokrovski; François Martin; Jean-Louis Hazemann; Jacques Schott; An X-ray absorption fine structure spectroscopy study of germanium-organic ligand complexes in aqueous solution. Chemical Geology 2000, 163, 151-165, 10.1016/s0009-2541(99)00102-3.
  2. Schleich C., Henze, C.; Trace analysis of germanium. Part 2. Polarographic behaviour and determination by adsorptive stripping voltammetry. Fresenius' Journal of Analytical Chemistry 1990, 163, 145.
  3. Robert Piech; Study on simultaneous measurements of trace gallium(III) and germanium(IV) by adsorptive stripping voltammetry using mercury film electrode. Journal of Applied Electrochemistry 2010, 41, 207-214, 10.1007/s10800-010-0225-4.
  4. Suw Young Ly; Sang Su Song; Sung Kuk Kim; Young Sam Jung; Chang Hyun Lee; Determination of Ge(IV) in rice in a mercury-coated glassy carbon electrode in the presence of catechol. Food Chemistry 2006, 95, 337-343, 10.1016/j.foodchem.2005.02.029.
  5. Alvarez, J.M., Calzon, J.G., Fonseca, J.L.; Electrochemical Reduction of Ge(IV) Catalyzed by o-Catechol at the Dropping Mercury Electrode and at the Hanging Mercury Drop Electrode after Adsorptive Preconcentration. Electroanalysis 1999, 11, 656.
  6. J L Muñiz Alvarez; J A García Calzón; J M López Fonseca; Square-wave voltammetry of the o-catechol-Ge(IV) catalytic system after adsorptive preconcentration at a hanging mercury drop electrode.. Talanta 2001, 53, 181.
  7. Kiyoshi Hasebe; Satoshi Hikima; Teiji Kakizaki; Tsuyoushi Iwashimizu; Koichi Aoki; Trace determination of germanium by means of adsorption waves in differential-pulse polarography. The Analyst 1990, 115, 413-416, 10.1039/an9901500413.
  8. Changqing Sun; Qian Gao; Liling Liu; Adsorptive stripping measurements of germanium(IV) in the presence of pyrogallol. Talanta 1995, 42, 881-884, 10.1016/0039-9140(95)01501-2.
  9. Julio César Aguilar; Josefina De Gyves; Determination of germanium(IV) in sulphide ores by differential pulse polarography in pyrogallol-sulfuric acid media. Analytica Chimica Acta 1995, 306, 243-247, 10.1016/0003-2670(95)00013-p.
  10. Gökmeşe, F., Gökmeşe, E., Osman Solak, A.; A new adsorptive square-wave stripping voltammetric method for the trace analysis of germanium. Hacettepe Journal of Biology and Chemistry 2008, 36, 215-221.
  11. Alan M. Bond; Steven Kratsis; O. Michael G. Newman; Adsorptive Stripping Voltammetric Determination of Germanium in Zinc Plant Electrolyte. Electroanalysis 1998, 10, 387-392, 10.1002/(SICI)1521-4109(199805)10:6%3c387::AID-ELAN387%3e3.0.CO;2-W.
  12. Malgorzata Grabarczyk; Optimization of Adsorptive Stripping Voltammetry Procedure Using Chloranilic Acid as a Complexing Agent for the Determination of Ultra-Trace Germanium in Natural Water Samples. Journal of The Electrochemical Society 2017, 164, H872-H876, 10.1149/2.0841713jes.
  13. Malgorzata Grabarczyk; Marzena Adamczyk; Bismuth film electrode and chloranilic acid as a new alternative for simple, fast and sensitive Ge(iv) quantification by adsorptive stripping voltammetry. RSC Advances 2018, 8, 15215-15221, 10.1039/c8ra01160e.
  14. R. G. Canham; D. A. Aikens; Nicholas Winograd; Glenn Mazepa; Mechanism of polarographic reduction of germanium(IV) in acidic catechol medium. The Journal of Physical Chemistry 1970, 74, 1082-1087, 10.1021/j100700a020.
  15. Shi Jinhui; Jiao Kui; Adsorptive complex catalytic polarographic determination of germanium in soils and vegetables. Analytica Chimica Acta 1995, 309, 103-109, 10.1016/0003-2670(95)00027-w.
  16. Shangwei Zhong; Jiali Su; Liang Chen; Jiefeng Tong; Wenfang Jia; Xiangjun Li; Hong Zou; Determination of Total Germanium in Chinese Herbal Remedies by Square-Wave Catalytic Adsorptive Cathodic Stripping Voltammetry at an Improved Bismuth Film Electrode. International Journal of Electrochemistry 2013, 2013, 1-7, 10.1155/2013/735019.
  17. Yi-Heng Li; Xin-Huan Chen; Mei-Hua Huang; Fang-Qin Zhou; Catalytic Adsorptive Stripping Voltammetry of Germanium(IV) in the Presence of Gallic Acid and Vanadium(IV)-EDTA. Electroanalysis 2007, 19, 704-708, 10.1002/elan.200603803.
  18. YueXia Zhang; Yongming Wu; Enhancement Mechanism of the Oscillopolarographic Current of Germanium(IV)-Trihydroxybenzoic Acid System and Application.. Analytical Sciences 1997, 13, 279-284, 10.2116/analsci.13.supplement_279.
  19. Jesús L. Muñiz Álvarez; Josefa A. García Calzón; Juan M. López Fonseca; Coupling of Ligand-Catalyzed Electroreduction of Metal Ions with Redox Electrocatalysis. Application of the o-Catechol-Ge(IV)-V(IV) Double Catalytic System for the Sensitive Determination of o-Catechol. Electroanalysis 2001, 13, 181-185, 10.1002/1521-4109(200103)13:3<181::aid-elan181>3.3.co;2-6.
  20. Jerzy Zarębski; Andrzej Bobrowski; Julia Gonciarczyk; Agnieszka Królicka; Extremely sensitive germanium stripping voltammetric determination with the use of a new Ge(IV)-catechol-V(IV)-HEDTA catalytic adsorptive system. Electrochimica Acta 2019, 324, 134859, 10.1016/j.electacta.2019.134859.
  21. Agnieszka Królicka; Jerzy Zarębski; Andrzej Bobrowski; Catalytic Adsorptive Stripping Voltammetric Determination of Germanium Employing the Oxidizing Properties of V(IV)-HEDTA Complex and Bismuth-Modified Carbon-Based Electrodes. Membranes 2021, 11, 524, 10.3390/membranes11070524.
  22. Jerzy Zarębski; Andrzej Bobrowski; Julia Gonciarczyk; Agnieszka Królicka; Selection of Optimal Ligand and Vanadium(IV) Complexonate for Sensitive Catalytic Adsorptive Stripping Voltammetric Quantification of Germanium. Electroanalysis 2020, 32, 2213–2219, 10.1002/elan.202060055.
  23. Jerzy Zarębski; Andrzej Bobrowski; Agnieszka Królicka; Julia Gonciarczyk; Vasiliki Manolopoulou; Anastasios Economou; A novel catalytic adsorptive stripping voltammetric method for the determination of germanium ultratraces in the presence of chloranilic acid and the V(IV)·HEDTA complex. Journal of Solid State Electrochemistry 2020, 24, 1-9, 10.1007/s10008-020-04669-0.
  24. Changqing Sun; Qian Gao; Jiubai Xi; Hongding Xu; Determination of germanium(IV) by catalytic cathodic stripping voltammetry. Analytica Chimica Acta 1995, 309, 89-93, 10.1016/0003-2670(95)00019-v.
  25. Agnieszka Królicka; Jerzy Zarębski; Andrzej Bobrowski; Application of Aminopolycarboxylic Complexes of V(IV) in Catalytic Adsorptive Stripping Voltammetry of Germanium. Chemosensors 2022, 10, 36, 10.3390/chemosensors10010036.
  26. Bobrowski Andrzej, Zarebski Jerzy; Catalytic Adsorptive Stripping Voltammetry. Electroanalysis 2000, 12, 1177, 10.1002/1521-4109(200010)12:153.0.CO;2-U.
More
© Text is available under the terms and conditions of the Creative Commons Attribution (CC BY) license; additional terms may apply. By using this site, you agree to the Terms and Conditions and Privacy Policy.
Upload a video for this entry
Information
Subjects: Chemistry, Analytical
Contributor MDPI registered users' name will be linked to their SciProfiles pages. To register with us, please refer to https://encyclopedia.pub/register :
Agnieszka Królicka
View Times: 584
Entry Collection: Chemical Bond
Revisions: 3 times (View History)
Update Date: 17 Feb 2022
Table of Contents
    1000/1000
    Hot Most Recent
    Feedback