Synergistic Effect In Extraction Research Articles

Structural and functional assessment of keratin extracted from chicken feathers using microwave-assisted l-cysteine method

Extracting and applying waste feather keratin are important environmental challenges. This study utilized microwave-assisted l-cysteine treatment on chicken feathers, pH adjustments varied reducing capacity of l-cysteine, while modulated microwave power explored synergistic extraction effects on properties of keratin. The highest yield of regenerated keratin was achieved at an l-cysteine concentration of 15 g/L, pH 12, and a microwave power of 400 W. Micromorphological and particle size results revealed that the keratin particle size increased with pH dependency, the highest proportion of particle size values in keratin increasing from 164 nm in L1 (extracted at pH 11) to 220 nm in L5 (extracted at pH 13). Increasing the intensity of both treatments led to a transition of the secondary structure of regenerated keratin from α-helix to β-sheet, but the increasing reducibility of the system resulted in a decrease in the content of tryptophan residues in keratin, whereas the increase in microwave power led to the masking of some fluorescent chromophores within the keratin. The regenerated keratin demonstrated low crystallinity, and it may have undergone refolding and aggregation under microwave-assisted highly reducing extraction conditions. The foaming properties indicated that the highly reducing extraction system significantly decreased foam stability from 95.4% for L1 to 19.8% for L5 (p < 0.05) and improved foaming ability to keratin. Considering the widespread applications of keratin, this study provides a comprehensive characterization of regenerated keratin under different extraction conditions, aiming to offer experimental materials and extraction conditions tailored to specific requirements in the field of biomaterials.

Selective recovery of transition metals from spent lithium-ion batteries leachate with Ni synergistic extraction system

Recycling spent lithium-ion batteries (LIBs) can not only generate ecological benefits but also realize low-carbon energy transition. Here, comprehensive recovery of transition metals from spent LIBs leachate using nickel (Ni) synergistic extraction system has been proposed. It was discovered that the combination of HEH(EH)P and Cyanex301 showed a strong synergistic extraction effect on Ni2+ and could also achieve the co-extraction of Ni2+, Co2+, Mn2+ after examining the extraction effects of single and mixed extractants of HEH(EH)P and Cyanex301. The mechanism of synergistic extraction of Ni2+ with mixed extractants was elucidate according to the slope analysis, FT-IR spectrometry and NMR spectrometry results. Then through a three stages of counter-current extraction process with 1.5 mol/L mixed extractant (XHEH(EH)P = 0.7, HEH(EH)P saponification degree of 60 %) and two stages of scrubbing process with 0.05 mol/L H2SO4, 99.18 % of Ni2+, 99.02 % of Co2+ and 99.93 % of Mn2+ were comprehensively recovered, while only 0.27 % of Li+ were lost. The Ni2+, Co2+, and Mn2+ loaded in the organic phase were entirely removed by a three stages of counter-current stripping process with HCl under O/A = 2.5/1. The synergistic extraction system still demonstrated outstanding reusability even after five cycles.

Multistep pH-peak-focusing liquid chromatography with a hydrophilic polymer gel column for separation of rare earth elements

Multistep pH-peak-focusing liquid chromatography with a column packed with a hydrophilic polymer gel (a cross-linked hydroxylated methacrylic polymer gel) was developed for separation of rare earth metal ions. Metal ions in a sample solution introduced to the column are chromatographically extracted into the stationary gel phase at the top of the column equilibrated with a basic solution used as the first mobile phase containing acetylacetone and 1,10-phenanthroline by synergistic extraction effect. After the sample solution is introduced, the mobile phases are delivered into the column by stepwise gradient elution in order of decreasing pH. Each metal ion is concentrated at a pH border formed between the zones of different pH in the column and moves toward the outlet of the column with the pH border. Mutual separation of La(III), Ce(III), Nd(III), Eu(III), Y(III), Tb(III), and Yb(III) was achieved by the present method for an 1-mL sample injection with the column of which the inner volume is 11.8 mL. The multistep pH-peak-focusing liquid chromatography with a hydrophilic polymer gel column developed in this study has great potential as a useful method for the separation of rare earth metal ions on a preparatory scale.

Closed-loop recovery of molybdenum and value-added reuse of tungsten from alloy waste in additive manufacturing

As metal additive manufacturing (MAM) technology is booming in the aerospace sector, alternatives to the traditional production methods of metals such as mining, processing, and refining with severe emissions are urgently needed. This study proposed a closed-loop route for efficient recovery of molybdenum (Mo) and value-added reuse of tungsten (W) from Cr–Co–Ni–Mo–W alloy waste in MAM. The results showed that the leaching efficiency of Mo and W reached 99.3% and 99.9%, respectively, using the dual chemical-physical means of mixed-alkali roasting and leaching by microwave heating, while the discharge of waste liquor containing Cr6+ was reduced. Leaching kinetic studies revealed that the metal leaching process was controlled by chemical reaction mechanism. Moreover, the 10%N1923 (primary amine)–5%TRPO (tri-alkyl phosphine oxide)–kerosene extraction system exhibited a synergistic extraction effect on Mo and W. After purification, Mo was recovered as Mo powder for MAM. Simultaneously, the recovered product of W, MnWO4, was applied as a photocatalytic material with excellent degradation of methylene blue dye. Ultimately, the proposed method obtained recovery efficiencies of 98.4% and 99.3% for Mo and W, respectively, achieving efficient and environmentally-friendly reuse of these key metals.

A green yttrium extraction system containing naphthenic acid, trioctyl/decylamine and isopropanol

Yttrium extraction usually produces waste water and suffers from difficulty in phase separation when using saponified naphthenic acid as the extractant. Herein, a non-saponified mixed extraction system containing naphthenic acid, trioctyl/decylamine and modifier was developed for yttrium extraction. Unlike the traditional saponified naphthenic acid system using long chain alcohol as the modifier, short chain alcohol of isopropanol was introduced into the extraction system for the first time. When using 20 vol% naphthenic acid, 40 vol% trioctyl/decylamine, 10 vol% sec-octyl alcohol and 25 vol% isopropanol diluted in 5 vol% n-hexane as extractant, a high yttrium extraction efficiency of above 60% could be obtained within a short phase separation time of ∼5 min. The yttrium separation from other rare earth elements could be achieved through two steps of LaCePrNdY/GdSmEuTbDyHoErTmLuYb grouping extraction followed by LaCePrNd/Y separation. Trioctyl/decylamine, sec-octyl alcohol and isopropanol showed the synergistic extraction effect with naphthenic acid, among which isopropanol was the strongest, followed by trioctyl/decylamine and sec-octyl alcohol. Trioctyl/decylamine could extract H+ produced from naphthenic acid, and isopropanol and/or sec-octyl alcohol could bond with naphthenic acid via hydrogen-bond interaction to prevent the formation of naphthenic acid dimers, leading to more coordination sites exposed for yttrium extraction. Furthermore, isopropanol and/or sec-octyl alcohol participated in the coordination in the extracted organic compound. The combination of the above three action had great contribution to the high extraction efficiency and the rapid phase separation. There was no waste water produced during extraction. Therefore, the proposed mixed system is a green and efficient system for yttrium extraction.

Electro-membrane extraction of lithium with D2EHPA/TBP compound extractant

A polymer inclusion membrane (PDT-PIM) composed of bis(2-ethylhexyl) phosphate (D2EHPA) and tributylphosphate (TBP) compound carrier is developed in this study. The PIM membrane carrier composition, thickness, voltage, two-phase solution environment and other factors for Li+ electro-membrane extraction (EME) behaviour are investigated using applied electric field assessment. Results showed that the PDT-PIM system composed of alkaline feed phase and acidic stripping phases can achieve preferential mass transfer to Li+ in the coexisting solution of Na+ and K+ ions. The D2EHPA functional group is responsible for the main mass transfer of ions. Synergistic extraction effect of TBP appears when D2EHPA/TBP (w/w) ratio is 1/2 and reaches maximum at a ratio close to 1/1. The total optimised carrier accounts for 70.6% of the mass percentage of PIM. The applied electric field can effectively increase the mass transfer rate but will reduce the selectivity of Li+ relative to Na+ and K+. Mass transfer coefficient (P) of 70.6% of PDT-PIM to Li+ can reach 12.9 μm s−‍1 and the initial flux of Li+ is 249 mg m−2 s−1 under a voltage of 20 V. Separation factor of Li+ relative to Na+ and K+ (SLi/Na and SLi/K) are 6.41 and 5.64 on 10 V as well as 2.56 and 2.51 on 20 V, respectively. Enrichment factor of Li+ of up to 9.02 shows acceptable stability after 120 h of continuous mass transfer of 1 L of 20 mg L−1 Li+ solution.

How acidity rules synergism and antagonism in liquid–liquid extraction by lipophilic extractants—Part II: application of the ienaic modelling

ABSTRACT In this article Part II, we consider the application of ienaic modeling for solvent extraction of rare earths in the case of the mixed DMDOHEMA/HDEHP extractant system. The system exhibits a synergistic extraction effect depending on the acid concentration and the extractant mole fraction, as demonstrated in the experimental article Part I. In this work, we directly compare experimental findings with theoretical predictions of the droplet model. The model considers the effective free energy of transfer as a combination of competing molecular forces, but contrary to previous micelle models that focus only on the dominant stoichiometry, it allows calculations of free energies of every possible spherical aggregate. The resulting image of the extraction process is that different behaviors can be obtained depending on the acidity and mole fraction of extractants, which are associated with different aggregation regimes in a complex free energy landscape of the system. Nevertheless, self-assembly is tuned by the extraction of all solutes, and not only the target metal cations.

Synergistic solvent extraction of lanthanide ions with mixtures of D2EHPA and MIDPA in phosphonium-based ionic liquids

In this study, the synergistic solvent extraction of lanthanide(III) with mixtures of di-(2-ethylhexyl)phosphoric acid (D2EHPA, H2A2) and monoisodecyl phosphoric acid (MIDPA, H2B2) in phosphonium-based ionic liquid was investigated from amide acid medium. The method of slope analysis was used for the determination of the extraction reaction. In the case of D2EHPA or MIDPA single extractant system, Ln(III) (Ln = Pr and Nd) was extracted as [LnA3HA] or [LnB3HB], respectively. Tb(III) or Dy(III) were extracted as [TbH2A2B2(NTf2)] or [DyH2A2B2(NTf2)] instead of [TbA3HA(NTf2)] or [DyA3HA(NTf2)] for D2EHPA and MIDPA synergistic system. According to the equilibrium constants (KA, KB and KAB) and the formation constants (β1, β1 and β3), it was found that the extracted complex [TbHA2B2] or [DyHA2B2] was more stable than [LnA3HA] or [LnB3HB] due to the synergistic effect of D2EHPA and MIDPA. The thermodynamic functions (ΔH, ΔG, and ΔS) were estimated from the temperature dependence of the synergistic extraction system. The result indicated that the synergistic extraction reaction was endothermically driven for this extraction system. Furthermore, the synergistic extraction effects were investigated to study the possibility of separating Dy(III) from Pr(III) and Nd(III) according to their separation factors.

Lithium Recovery from the Mother Liquor Obtained in the Process of Li2CO3 Production

It is important to find an effective way to separate lithium from the mother liquor obtained by the reaction of lithium chloride/lithium sulfate and sodium carbonate. A synergistic solvent extraction system containing 1-phenyl-3-heptyl-1,3-propanedione (PHPD) and liquid mixture of trialkyl-phosphine oxides (Cyanex923) to separate lithium from the system of Li++Na++Cl–+CO32–+H2O was developed. The pH of the aqueous solution showed an important effect on the lithium extraction. At pH 13.06, PHPD alone showed a high extractability of lithium, but the addition of Cyanex923 led to a high separation ability of lithium over sodium due to the synergistic extraction effect. For a single extraction, the extraction percentage of lithium was 97.83% from the solution with 1.39 g·L–1 Li and 68.97 g·L–1 Na using the extraction system containing 0.4 mol·L–1 PHPD and 0.2 mol·L–1 Cyanex923 at the A/O ratio of 1:1, initial aqueous pH of 13.06, and 293.15 K, and the separation factor of lithium over sodium reached 475.06. On...

Synergistic Effect in Green Extraction of Noble Metals and Its Consequences

Extraction of silver into water occurs from its apparently inert metal surface by the simple carbohydrate glucose. Here we show that there are large synergistic effects in the extraction process, which results in ca. 45 times larger leaching with specific molecules, when used along with glucose. While glucose (1 g) alone can extract ca. 650 ppb of silver from the metal, 60 mg of it extracts ca. 30000 ppb in a combination with 200 mg of glutathione (GSH) under similar experimental conditions of 70 °C and an extraction time of 7 d, in deionized (DI) water (200 mL). This enhancement is similar when glucose is replaced with cyclodextrin (CD). This enhanced concentration of silver in solution enables the formation of the silver clusters protected with glutathione and cyclodextrin, Ag20(SG)15CD3–, in the presence of a reducing agent. A similar extraction for copper leads to excessive leaching, and typical concentrations are even higher than the solubility limit of the copper–glutathione complex. As a result, these complexes are precipitated. This synergistic extraction is observed for zinc and stainless steel as well. Enhanced extraction is a result of the formation of complexes of metals with glutathione and the consequent leaching of the complex into solution as well as the stabilization of the complex by inclusion complexation with cyclodextrin. Enhanced leaching in the presence of glucose is mostly due to simultaneous complexation with glucose as well as glutathione. The science presented may be used for the green extraction of different metals and could be a new potential top‐down approach for metal cluster synthesis. This may also be useful for green and sustained leaching of minerals into water to regulate its quality.

Ionic liquid-based synergistic extraction of rare earths nitrates without diluent: Typical ion-association mechanism

Abstract The coexistence of tricaprylmethylammonium nitrate ([A336][NO 3 ]) and Di(2-ethylhexyl) 2-ethylhexyl phosphonate (DEHEHP) has been found an obvious synergistic extraction effect for rare earths nitrates. In this work, synergistic extraction behaviors without any diluent for rare earth nitrates based on tri(hexyl)tetradecylphosphonium chloride (Cyphos®IL 101, [P66614][Cl]) and DEHEHP have been further investigated. Pr(III) was still used as a model RE, and the maximum synergistic extraction distribution ratio was obtained at a volume ratio of 2:3 for [P66614][Cl] and DEHEHP. The synergistic enhancement coefficients have been tested for the whole rare earths. Results show that there is an obvious synergistic enhancement effect for light REs (La-Sm) and an anti-synergistic effect for Gd-Lu including Y. The effects of acidity, anions and metal ion concentrations on the extraction have been investigated. The extraction mechanism has been confirmed to be the typical ion-association reactions. The maximum loading capacity is 0.78 mol/L Pr at 293.15 K. The extraction ability of [P66614][Cl]-DEHEHP is superior to that of reported [A336][NO 3 ]-DEHEHP, and is also greater than that of common acidic organophosphate-kerosene extraction system. Stripping, recyclability, and selectivity between REs and non-REs, has also been investigated.

Analysis of perfluorooctane sulfonate and perfluorooctanoic acid with a mixed-mode coating-based solid-phase microextraction fiber

A novel mixed-mode coating-based solid-phase microextraction (SPME) fiber was prepared by chemical bonding dimethyloctadecyl [3-(trimethoxysilyl) propyl] ammonium chloride and 3-(trimethoxysilyl)-1-propanamine, the sol–gel precursors, on an anodized Ti wire, aiming to effectively adsorb perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA). The anodized Ti wire with uniform TiO2 nanotube arrays provides high mechanical strength and strong adhesion to the mixed-mode coating. The prepared fiber shows excellent organic solvent stability due to the covalent bonding between the coating and the fiber, and significantly higher extraction efficiency than the commercial fibers, 100μm polydimethylsiloxane and 85μm polyacrylate fiber, due to the synergistic extraction effects of the coating functional groups. Good linearity (R2=0.9994 for PFOS, R2=0.9992 for PFOA) was obtained with detection limits of 2.5 and 7.5pgmL−1 for PFOS and PFOA, respectively. Recoveries were in the range of 88%–102%. The proposed method was successfully applied in the analysis of PFOS and PFOA in a local river with the results of 0.05 and 0.06ngmL−1, respectively.

Bifunctional Fluoroionphore-Ionic Liquid Hybrid for Toxic Heavy Metal Ions: Improving Its Performance via the Synergistic Extraction Strategy

Several heavy metal ions (HMIs), such as Cd(2+), Pb(2+), and Hg(2+), are highly toxic even at very low concentrations. Although a large number of fluoroionphores have been synthesized for HMIs, only a few of them show detection limits that are below the maximum contamination levels in drinking water (usually in the nM range), and few of them can simultaneously detect and remove HMIs. In this work, we report a new fluoroionphore-ionic liquid hybrid-based strategy to improve the performance of classic fluoroionphores via a synergistic extraction effect and realize simultaneous instrument-free detection and removal of HMIs. As a proof-of-concept, Hg(2+) was chosen as a model HMI, and a rhodamine thiospirolactam was chosen as a model fluoroionphore to construct bifunctional fluoroionphore-ionic liquid hybrid 1. The new sensing system could provide obviously improved sensitivity by simply increasing the aqueous-to-ionic liquid phase volume ratio to 10:1, resulting in a detection limit of 800 pM for Hg(2+), and afford extraction efficiencies larger than 99% for Hg(2+). The novel strategy provides a general platform for highly sensitive detection and removal of various HMIs in aqueous samples and holds promise for environmental and biomedical applications.

Applications of the binary mixture of sec-octylphenoxyacetic acid and 8-hydroxyquinoline to the extraction of rare earth elements

In the present work, a binary mixture of sec-octylphenoxyacetic acid (CA12, H 2A 2) and 8-hydroxyquinoline (HQ) was applied to the extraction of rare earth elements. The mixture had synergistic extraction effects on all the lanthanoids (except polonium) and yttrium. The separation ability of rare earth elements was studied according to the various extraction effects. As representatives of light, medium, and heavy rare earth elements, the compositions of the extracted species for cerium, terbium, and lutetium were investigated by the slope analysis method and constant molar ratio method. The values of the equilibrium constants and the thermodynamic functions were also determined.

Characteristic of synergistic extraction of oxalic acid with system from rare earth metallurgical wastewater

Large amount of high concentration acidic wastewater would be produced in the conversion process of chloride rare earth into oxide rare earth. It was a mixed solution of oxalic acid and hydrochloric acid, so the recycling use was very difficult. The method of liquid-liquid extraction was proposed in this paper to achieve wastewater treatment and reclamation. The mechanism of extraction of oxalic acid from the wastewater with the systems of 50% TOB+45% kerosene and 5% 2-ethyl hexanol was investigated. The composition and structure of the extracted species and the establishment of the mathematical model of the oxalic acid extraction were determined by the use of saturation method, equimolar series method. The results showed that extraction of oxalic acid by TOB was a neutral association extraction, oxalic acid existed mainly in a molecular form in the organic phase, and the extraction combination ratio was 2:1. The duality extraction system composed of extractant TOB and TOC had synergistic extraction effect on oxalic acid and chlorhydric acid, and the extraction distribution ratio was improved greatly. The optimum volume fraction of TOB was 0.6-0.8.

Extraction of rare earths using mixtures of sec-octylphenoxy acetic acid and organophosphorus acids

The extraction of rare earths from nitrate medium using three organophosphorus acids, 2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester (HEHEHP), di-(2-ethylhexyl) phosphoric acid (D2EHPA), bis(2,4,4-trimethylpentyl) phosphinic acid (Cyanex272), and their mixtures with sec-octylphenoxy acetic acid (CA12) has been studied in detail. The mixtures have different extraction effects on various rare earths. Synergistic extraction effects are only found when light rare earths and yttrium (III) are extracted with mixtures of D2EHPA and CA12. The possibilities of separating the rare earths with these mixtures are investigated according to the extractabilities. It is feasible and advantageous to separate yttrium (III) from the lanthanoids (III) with HEHEHP + CA12 and D2EHPA+CA12 mixtures at proper extractant ratios. The separation of yttrium (III) from heavy rare earths is also possible with mixtures of Cyanex272 and CA12.

Solvent extraction studies of Sm(III) from nitrate medium and separation factors of rare earth elements with mixtures of sec‐octylphenoxyacetic acid and 1,10‐phenthroline

AbstractBACKGROUND: Liquid–liquid extraction is widely used for the separation of rare earths, among which synergistic extraction has attracted more and more attention. Numerous types of synergistic extraction systems have been applied to rare earths with high extraction efficiency and selectivities. In the present study, mixtures of sec‐octylphenoxyacetic acid (CA12, H2A2) and 1,10‐phenanthroline (phen, B) have been used for the extraction of rare earths from nitrate medium. The stoichiometry of samarium(III) extraction has been studied using the methods of slope analysis and constant molar ratio. The possibility of using synergistic extraction effects to separate rare earths has also been studied.RESULTS: Mixtures of CA12 and phen display synergistic effects in the extraction of rare earth elements giving maximum enhancement coefficients of 5.5 (La); 13.7 (Nd); 15.9 (Sm); 24.5 (Tb); 45.4 (Yb) and 12.3 (Y). Samarium(III) is extracted as SmHA4B3 with mixtures of CA12 and phen instead of SmHA4 when extracted with CA12 alone. The calculated logarithm of the equilibrium constant is 6.0 and the thermodynamic functions, ΔH, ΔG, and ΔS, have been calculated as 4.3 kJ mol−1, − 33.7 kJ mol−1 and 129.7 J mol−1 K−1, respectively.CONCLUSION: Mixtures of CA12 and phen exhibit synergistic effects on rare earth elements. Graphical and numerical methods have been successfully used to determine their stoichiometries. The different synergistic effects may provide the possibility of separating yttrium from heavy lanthanoids at an appropriate ratio of CA12 and phen. Copyright © 2010 Society of Chemical Industry

Synergistic Effects in Extraction and Separation of Praseodymium(III) and Neodymium(III) with 8-Hydroxyquinoline in the Presence of 2-Ethylhexyl Phosphonic Acid Mono-2-Ethylhexyl Ester

In this paper, the extraction behaviors of praseodymium(III) from an aqueous chloride−acetate medium, using 8-hydroxyquinoline (HQ), 2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester (P507, HL) and their mixture, were studied, using ultraviolet−visible light (UV−vis) absorption spectroscopy. The binary equilibrium constants (log K1, log K2) for the complex formation PrL3·3HL and PrQ3 in the organic phase were determined to be −1.98 for 2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester and −11.54 for HQ, respectively. The overall equilibrium constant (log K12) for the ternary species PrQ2L10H9 was estimated to be 6.01. The largest synergistic enhancement factor was calculated to be 5.39, corresponding to a HQ:P507 concentration ratio of 3:7 at pH 3.6. When P507 was added into HQ, the entire stripping could be achieved at an aqueous sulfuric acid concentration of ∼0.02 M. In addition, for praseodymium(III) and neodymium(III), the mixture of HQ and P507 showed higher separation selectivity than HQ or P...

Synergistic extraction of uranium(VI) with tri-n-butyl phosphate and i-butyldodecylsulfoxide

The synergistic extraction of uranium(VI) from aqueous nitric acid solution with a mixture of tri-n-butyl phosphate (TBP) and i-butyldodecylsulfoxide (BDSO) in toluene was investigated. The effects of the concentrations of extractant, nitric acid, sodium nitrate and sodium oxalate on the distribution ratios of uranium(VI) have been studied. The values of enthalpy change for the extraction reactions with BDSO, TBP and a mixture of TBP and BDSO in toluene were -23.2±0.8 kJ/mol, -29.2±1.4 kJ/mol and -30.6±0.6 kJ/mol, respectively. It has been found that the maximum synergistic extraction effect occurs when the molar ratio of TBP to BDSO is close to 1. The composition of the complex of the synergistic extraction is UO2(NO3)2 . BDSO . TBP.

Extraction of Am(III) from Nitric Acid Solutions with Bis(diphenylphosphinylmethyl)phosphinic Acid

Extraction of trace quantities of Am(III) from aqueous HNO3 solutions with solutions of bis(diphenylphosphinylmethyl)phosphinic acid (I), bis[2-(diphenylphosphinyl)phenoxymethyl]phosphinic acid (II), and bis[2-(diphenylphosphinylmethyl)phenoxymethyl]phosphinic acid (III) in dichloroethane was studied. The stoichiometry of the extractable complexes was determined; the effect of organic diluent on the extraction was considered. The extractive power of the reagents toward Am(III) grows in the order III < II < I. Acid I surpasses in the extractive power a neutral bidentate extractant, tetraphenylmethylenediphosphine dioxide (TPMDPD), by three orders of magnitude. A synergistic effect in extraction of Am with mixtures of TPMDPD and acid I was revealed.