Sodium Dithionite Research Articles

Mineralogical characterization and beneficiation study of kaolin from Equador (RN) and Junco do Seridó (PB) to increase the brightness index

Abstract Kaolin is a rock composed mainly of kaolinite. It is used in many industrial segments, such as paper and ceramics. However, for these uses it is necessary to submit the ore to appropriate beneficiation, which generally involves magnetic separation and chemical bleaching, aiming to remove iron oxide and hydroxide, raising brightness index. This work reports the mineralogical characterization and analysis of the beneficiation of three samples of kaolin, two from Equador (Rio Grande do Norte - RN) and the third from Junco do Seridó (Paraíba - PB). The samples were submitted to granulometric classification in sieve of 44 μm, magnetic separation in a magnetic induction of 14000 gauss, and chemical bleaching with sodium dithionite during 240 min. The processes were divided into two beneficiation routes. X-ray diffraction, chemical analysis by X-ray fluorescence and scanning electron microscopy were used for mineralogical characterization of the ore and measurement of the brightness index, while electron paramagnetic resonance was applied to study the variation of iron oxides and hydroxides during beneficiation. The results indicate that just 30 min of chemical bleaching without magnetic separation was sufficient to increase the brightness index from 78.2 to 90.2% and from 91.3 to 95.7% in the two samples from Equador (RN) and from 86.9 to 90.4% in the sample from Junco do Seridó (PB). The magnetic separation, although causing a small increase in the brightness index, was inefficient for removal of iron oxides and hydroxides. The results indicated no need for using magnetic separation in plants for beneficiation of kaolin from these two locations, providing the reduction of production costs allowing better exploitation of the ore.

Development of Time-course Oxygen Binding Analysis for Hemoglobin-based Oxygen Carriers.

Developing blood substitutes is in urgent demand for chronic blood shortage all over the world. In this connection, the oxygen binding behavior of hemoglobin-based oxygen carriers (HBOCs) is one of the most important characteristics. However, present methods available for estimating oxygen binding behavior have need of expensive apparatus, and also are not suitable for high-throughput and the time-course analysis. To overcome these problems, we proposed a simple analysis method for the time-course oxygen binding behavior of HBOCs, which employs a general UV-Vis microplate reader and a common reagent, sodium dithionite, as a reductant for HBOCs and an oxygen scavenger. Our method enabled time-course oxygen binding behavior analysis of HBOCs in a simple manner, and obtained data corresponding with those by the conventional method. Thus, our developed method will accelerate the development of HBOCs due to easy oxygen binding analysis.

Cationization of cellulose/polyamide on UV protection, bio‐activity, and electro‐conductivity of graphene oxide‐treated fabric

ABSTRACTIn this work, cationized cotton/nylon fabric was treated with reduced graphene oxide (rGO) to produce highly conductive fabric. The fabric was cationized with 3‐chloro‐2‐hydroxy propyl trimethyl ammonium chloride to attract more anionic GO. The fabric was then treated with GO followed by reduction with sodium dithionite. The results of energy‐dispersive X‐ray spectroscopy, X‐ray diffraction, and X‐ray photoelectron spectroscopy indicated entire coverage of the fabric surface with rGO. The color of fabrics changed to gray‐black and the electrical resistance decreased to 0.6 × 103 Ω sq−1. The washing fastness was measured according to ISO 105‐CO5 for color change and also electrical resistance of the samples demonstrated well stability of rGO on the fabric surface. The antibacterial activities of the treated fabrics improved against Gram‐negative bacteria including Escherichia coli (84.8%) and Pseudomonas aeruginosa (96.4%) and also Gram‐positive bacteria consisting Staphylococcus aureus (100%) and Enterococcus faecalis (98.4%). Further, the treated fabrics indicated an excellent UV reflectance of 100%. Finally heating of the cationized rGO fabric at 220 °C displayed a lower electrical resistance of 0.5 × 103 Ω sq−1. The thermogravimetric analysis showed that heating has a slight effect on the dimensional thermal stability of the treated fabric as shrunk 2.43%. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45493.

Advanced treatment of sodium dithionite wastewater using the combination of coagulation, catalytic ozonation, and SBR

ABSTRACTA combined process of coagulation–catalytic ozonation–anaerobic sequencing batch reactor (ASBR)–SBR was developed at lab scale for treating a real sodium dithionite wastewater with an initial chemical oxygen demand (COD) of 21,760–22,450 mg/L. Catalytic ozonation with the prepared cerium oxide (CeO2)/granular activated carbon catalyst significantly enhances wastewater biodegradability and reduces wastewater microtoxicity. The results show that, under the optimum conditions, the removal efficiencies of COD and suspended solids are averagely 99.3% and 95.6%, respectively, and the quality of final effluent can meet the national discharge standard of China. The coagulation and ASBR processes remove a considerable proportion of organic matter, while the SBR plays an important role in post-polish of final effluent. The ecotoxicity of the wastewater is greatly reduced after undergoing the hybrid treatment. This work demonstrates that the hybrid system has the potential to be applied for the advanced treatment of high-strength industrial wastewater.

Simple synthesis of 3-hydroxyquinolines via Na2S2O4-mediated reductive cyclization of (2-(2-nitrophenyl)oxiran-1-yl)(aryl)methanones (o-nitrobenzalacetophenone oxides)

An efficient sodium dithionite (Na2S2O4)-mediated method for construction of 3-hydroxyquinolines via in situ Meinwald rearrangement/intramolecular reductive cyclization of o-nitrobenzalacetophenone oxides has been developed. The practical approach is of excellent functional group compatibility with as high as 98% yield under mild reaction conditions. Moreover, further manipulation successfully furnished 4-bromo substituted derivatives which may provide a promising potential application in exploring biologically active analogs of 3-hydroxyquinolines.

Comparison of thermal hazards of sodium dithionite and thiourea dioxide from thermal analysis (DSC-TG), small-scale self-heating experiments and FTIR smoke gas analysis

Sodium dithionite and thiourea dioxide are two typical reducing agents commonly used in industry. This paper compared the thermal hazards of sodium dithionite and thiourea dioxide based on DSC-TG (Differential Scanning Calorimetry and Thermogravimetry) thermal analysis, small-scale self-heating experiments and FTIR smoke gas analysis. From the thermal analysis (DSC-TG), sodium dithionite starts to lose crystal water at the temperature around 60 °C which makes the sodium dithionite very unstable at relatively lower temperature. The decomposition of sodium dithionite has a close correlation with oxygen while the decomposition of thiourea dioxide has little relationship with oxygen. Small-scale self-heating experiments were designed to reflect the self-heating and spontaneous combustion properties of the characteristic dimension 20 cm. The small-scale self-heating experiments show that there is a little gap between the Critical Ambient Temperature (CAT) of sodium dithionite and thiourea dioxide. From FTIR smoke gas analysis, the smoke of thiourea dioxide (decomposition or combustion) is far more dangerous than sodium dithionite. Although the risk of spontaneous combustion for sodium dithionite is higher than thiourea dioxide, the thermal hazards of thiourea dioxide are far higher than sodium dithionite as the decomposition and combustion of thiourea dioxide would release far more heat and dangerous smokes.

Renaturation of Cytochrome c Dissolved in Polar Phosphonate-type Ionic Liquids Using Highly Polar Zwitterions

We present a method for the renaturation of denatured cytochrome c in a phosphonate-type ionic liquid with the addition of a suitable zwitterion and a small amount of water. The polarity of zwitterions was found to be a critical property for the renaturation of cytochrome c. The renatured cytochrome c was reduced by the addition of sodium dithionite, suggesting that the renatured cytochrome c retains its redox ability.

Extraction process optimization of Juncus plant fibers for its use in a green composite

In the context of the development of green building materials using plant fibers, this research has focused on the characterization of natural fibers extracted from Juncus plant, commonly called Juncus. A well-known chemical extraction method was applied here for the first time at our knowledge to the Juncus plant, in order to obtain better mechanical characteristics (tensile strength and elastic modulus) and better surface morphology. Therefore, a chemical treatment with alkalization through various factors such as temperature, NaOH concentration (alkalizing agent), presence or not of sodium dithionite Na2S2O4 (for reducing lignin) and sodium hypochlorite NaOCl (chlorine bleach delignification agent) was performed. This study aims to determine the effects of different chemical treatments applied to the fiber extraction of Juncus stem, on the change in fiber diameter, surface state morphology, density, tensile strength and elastic modulus. As one of the Juncus fiber treatments considered in this work, the cold alkali-treatment did not give good results in terms of delignification of the Juncus fibers (There is always non-cellulosic products on the treated fiber) and low values of tensile stress and modulus of elasticity. The treatment with a solution of 8% NaOH, sodium hypochlorite and sodium dithionite at hot temperature present the best result due to the effective delignification of the fibers which has allowed reaching highest tensile strength and highest elastic modulus.

Insights into the catalysis of a lysine-tryptophan bond in bacterial peptides by a SPASM domain radical S-adenosylmethionine (SAM) peptide cyclase

Radical S-adenosylmethionine (SAM) enzymes are emerging as a major superfamily of biological catalysts involved in the biosynthesis of the broad family of bioactive peptides called ribosomally synthesized and post-translationally modified peptides (RiPPs). These enzymes have been shown to catalyze unconventional reactions, such as methyl transfer to electrophilic carbon atoms, sulfur to Cα atom thioether bonds, or carbon-carbon bond formation. Recently, a novel radical SAM enzyme catalyzing the formation of a lysine-tryptophan bond has been identified in Streptococcus thermophilus, and a reaction mechanism has been proposed. By combining site-directed mutagenesis, biochemical assays, and spectroscopic analyses, we show here that this enzyme, belonging to the emerging family of SPASM domain radical SAM enzymes, likely contains three [4Fe-4S] clusters. Notably, our data support that the seven conserved cysteine residues, present within the SPASM domain, are critical for enzyme activity. In addition, we uncovered the minimum substrate requirements and demonstrate that KW cyclic peptides are more widespread than anticipated, notably in pathogenic bacteria. Finally, we show a strict specificity of the enzyme for lysine and tryptophan residues and the dependence of an eight-amino acid leader peptide for activity. Altogether, our study suggests novel mechanistic links among SPASM domain radical SAM enzymes and supports the involvement of non-cysteinyl ligands in the coordination of auxiliary clusters.

Resonance Raman and UV‐Visible Microscopy Reveals that Conditioning Red Blood Cells with Repeated Doses of Sodium Dithionite Increases Haemoglobin Oxygen Uptake

AbstractHere we report that successive additions of fresh dithionite to a suspension of red blood cells (RBCs) increase the capacity of the cells to uptake oxygen. This effect was not observed when the RBCs were similarly preconditioned using gaseous N2 to induce short episodes of hypoxia. The effect of successive sodium dithionite and N2 gas additions on a population of functional erythrocytes was monitored using Raman confocal microscopy, with 514 nm excitation, and UV–visible microscopy. The results indicate that successive additions of sodium dithionite in a suspension of red blood cells leads to an increase in both the rate and the capacity of the RBCs to uptake oxygen. The sodium dithionite did not cause haemoglobin from lysed RBCs to uptake more oxygen after successive additions and hence this effect was only observed in functional intact RBCs. Experiments performed with polarised Raman spectroscopy suggest that sodium dithionite increases the disorder of Hb in the RBC facilitating oxygen diffusion.

Study of the residual Sodium Hydrosulfite (Dithionite) levels in produced industrial breads: case study in Hamadan

Study of the residual Sodium Hydrosulfite (Dithionite) levels in produced industrial breads: case study in Hamadan

Refinement of industrial kaolin by removal of iron-bearing impurities using thiourea dioxide under mechanical activation

This study reports a series of experiments conducted to evaluate the suitability of thiourea dioxide (TD) under mechanical activation, in bleaching iron-bearing impurities from raw kaolin. The optimum conditions for the maximum whiteness of 76.32% were determined as follows: rotation speed of ball mill, 400rpm; activation time, 1.5h; TD dosage, 0.8% of kaolin mass; solid-to-liquid ratio, 1:2; pH, 8.0; room temperature. The effect of grinding causes the partial surface amorphization of kaolin particles and a decrease in the dehydroxylation temperature. The assistance of grinding leads to a higher iron removal when compared with the conventional bleaching method using sodium hydrosulfite.

Inhibition of rapid delayed rectifier potassium current (IKr) by ischemia/reperfusion and its recovery by vitamin E in ventricular myocytes

Ischemia/reperfusion (I/R) induces prolongation of QT interval and action potential duration (APD), which is a major cardiac electrical disorder in patients with arrhythmias. However, the mechanism of QT interval prolongation induced by I/R remains unclear. In the present study, we hypothesized that the rapid component of delayed rectifier potassium (IKr) channel plays an important role in I/R-induced QT interval prolongation. We observed a marked attenuation of IKr and a significant prolongation of action potential duration (APD) in a simulated I/R system with sodium dithionite (Na2S2O4) in ventricular myocytes of guinea pigs. The IKr current density was inhibited by 64% and APD increased by 87% respectively. Moreover, the inhibition of IKr is primarily ascribed to overproduction of reactive oxygen species (ROS) by I/R, which can be partly reversed by antioxidant vitamin E (100μmol/L). The value of IKr tail current density increased from 0.516±0.040 pA/pF in I/R to 0.939±0.091 pA/pF when treated with vitamin E. Moreover, we also demonstrated that QTc interval was increased by I/R and reversed by Vitamin E in isolated guinea pig hearts. In conclusion, the inhibition of IKr is one of the underlying mechanisms of prolongation of QT interval and APD in I/R. Vitamin E might have a benefit in coronary reperfusion therapy.

Influence of flooding on exchangeability and release of stable and radioactive cesium in contaminated paddy soil

ABSTRACTAn incubation experiment was conducted to clarify how soil flooding influences the mobility of radioactive cesium (RCs: 134Cs and 137Cs) in paddy soil after aging, focusing on the effects of ammonium increase and soil reduction. We used two contaminated paddy soils (A and B, both Gleyic Fluvisols) aged for 26 months after the Tokyo Electric Power Company’s Fukushima Daiichi Nuclear Power Plant accidents, and analyzed both the RCs and stable cesium (133Cs). The soils were incubated in a flooded condition, with or without the addition of ammonium fertilizer, for 1, 15 and 30 d, and in an unflooded condition for 30 d. After the incubation periods, we quantified 133Cs concentration in the soil solution, 133Cs and RCs released from soil in 0.01 mol L–1 calcium chloride solution as parameters of release intensity, and 133Cs and RCs extracted with 1 mol L−1 ammonium acetate solution as exchangeable quantities, and analyzed their relationship with ammonium content and redox condition in soil. The increase of ammonium by both ammonification and fertilizer application promoted release of exchangeable 133Cs and RCs to the soil solution and calcium solution. When ammonium content became low during unflooded incubation, exchangeable 133Cs and RCs themselves decreased. When soil reduction progressed with flooded incubation, however, exchangeable 133Cs and RCs decreased, despite high ammonium content. To estimate the influence of soil reduction on the exchangeability of RCs, soil A was sequentially extracted with sodium hydrosulfite (a reducing agent) and ammonium acetate solutions. Compared with a control treatment using sodium sulfate instead of sodium hydrosulfite, the total RCs extracted by the reducing treatment was 42% lower, indicating that soil reduction decreases RCs exchangeability. Through these analyses of 133Cs and RCs, we conclude that soil flooding influences the mobility of aged RCs through two opposite effects: the release of exchangeable RCs into soil solution is enhanced with increased ammonium, while the exchangeable RCs itself decreases due to soil reduction.

Thermal and Alkali Stability of Sodium Dithionite Studied Using ATR-FTIR Spectroscopy

Sodium dithionite (Na2S2O4) may have the potential to be used as a reducing agent for the stabilization of glucomannan in kraft cooking for increased pulp yield. However, due to the fact that dithionite decomposes under the conditions of kraft pulping, studies of the effects of dithionite in kraft pulping are non-conclusive; sometimes clearly showing an increased yield, and in other studies no effect at all. The specific conditions influencing dithionite degradation are also unclear. For that reason, this study was conducted to determine the thermal and chemical stability of sodium dithionite with respect to specific factors, such as the pH, temperature, heating time, and the concentration of sodium dithionite solution. The study was performed under anaerobic conditions using attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy. The thermal and alkali stability of the sodium dithionite solution was shown to decrease with increasing temperature, heating time, and concentration of the solution at the alkaline conditions studied. The thermal stability decreased rapidly at weak alkalinity (pH 9) as well as in high alkalinity (pH 14), whereas the sodium dithionite was rather stable at moderate alkalinity (pH 11.5 to pH 13).

Multifunctional surface modification of silk fabric via graphene oxide repeatedly coating and chemical reduction method

Multifunctional silk fabrics with electrical conductive, anti-ultraviolet and water repellent were successfully prepared by surface modification with graphene oxide (GO). The yellow-brown GO deposited on the surface of silk fabric was converted into graphitic black reduced graphene (RGO) by sodium hydrosulfite. The surface properties of silk fabrics were changed by repeatedly RGO coating process, which have been proved by SEM and XPS. The SEM results showed that the RGO sheets were successive form a continuously thin film on the surface of silk fabrics, and the deposition of GO or RGO also can be proved by XPS. The electrical conductivity was tested by electrical surface resistance value of the silk fabric, the surface resistance decreased with increasing of RGO surface modification times, and a low surface resistance value reached to 3.24 KΩ cm−1 after 9 times of modification, indicating the silk obtained excellent conductivity. The UPF value of one time GO modification silk fabric (silk-1RGO) was enhanced significantly to 24.45 in comparison to 10.40 of original silk. The contact angle of RGO coating silk samples was all above of 120°. The durability of RGO coated silk fabrics was tested by laundering. The electrical surface resistance of silk-4RGO (65.74KΩcm−1), silk-6RGO (15.54KΩcm−1) and silk-8RGO (3.86KΩcm−1) fabrics was up to 86.82, 22.30 and 6.57KΩcm−1 after 10 times of standard washing, respectively. The UPF value, contact angle and color differences of RGO modified silk fabric slightly changed before and after 10 times of standard washing. Therefore, the washing fastness of electric conduction, anti-ultraviolet and water repellent multifunctional silk fabrics was excellent.

Electro-conductivity, bioactivity and UV protection of graphene oxide-treated cellulosic/polyamide fabric using inorganic and organic reducing agents

Here, graphene oxide (GO) was treated on the cellulosic/polyamide fabric reduced with various inorganic and organic compounds and compared the color changes, field emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction, electrical resistivity, antibacterial/antifungal and ultraviolet protection properties. The graphite oxide was first synthesized using graphite and sonicated to obtain GO. It was then dissolved in distilled water along with cetyltrimethylammonium bromide (CTAB) to prepare a stable solution for long-time adsorbing more and uniform GO on cellulosic/polyamide fabric through exhaustion method. The GO-treated fabric was reduced to reduced graphene oxide (rGO) with inorganic and organic reducing agents including sodium dithionite with and without sodium hydroxide and dopamine hydrochloride at various temperatures. More fabricated GO reduced to rGO at higher temperature using dopamine produced lower electrical resistance. The antimicrobial activities of various samples were tested against two Gram-negative bacteria, E. coli and P. aeruginosa, two Gram-positive bacteria, S. aureus and E. faecalis and one eukaryotic fungus C. albicans. Ultraviolet protection was examined through reflectance spectra showed no UV transmittance from most of the treated fabrics. Further, CTAB was effective to load more GO on the fabric improved electrical resistance and higher antibacterial properties using both reducing agents.

Remediation of hexavalent chromium contamination in chromite ore processing residue by sodium dithionite and sodium phosphate addition and its mechanism

Large amounts of chromite ore processing residue (COPR) wastes have been deposited in many countries worldwide, generating significant contamination issues from the highly mobile and toxic hexavalent chromium species (Cr(VI)). In this study, sodium dithionite (Na2S2O4) was used to reduce Cr(VI) to Cr(III) in COPR containing high available Fe, and then sodium phosphate (Na3PO4) was utilized to further immobilize Cr(III), via a two-step procedure (TSP). Remediation and immobilization processes and mechanisms were systematically investigated using batch experiments, sequential extraction studies, X-ray diffraction (XRD) and X-ray Photoelectron Spectroscopy (XPS). Results showed that Na2S2O4 effectively reduced Cr(VI) to Cr(III), catalyzed by Fe(III). The subsequent addition of Na3PO4 further immobilized Cr(III) by the formation of crystalline CrPO4·6H2O. However, addition of Na3PO4 simultaneously with Na2S2O4 (via a one-step procedure, OSP) impeded Cr(VI) reduction due to the competitive reaction of Na3PO4 and Na2S2O4 with Fe(III). Thus, the remediation efficiency of the TSP was much higher than the corresponding OSP. Using an optimal dosage in the two-step procedure (Na2S2O4 at a dosage of 12× the stoichiometric requirement for 15 days, and then Na3PO4 in a molar ratio (i.e. Na3PO4: initial Cr(VI)) of 4:1 for another 15 days), the total dissolved Cr in the leachate determined via Toxicity Characteristic Leaching Procedure (TCLP Cr) testing of our samples was reduced to 3.8 mg/L (from an initial TCLP Cr of 112.2 mg/L, i.e. at >96% efficiency).

Differences between the Interactions of Linear and Tetrahedron-like Ditopic Guests with Cucurbit[8]uril: Steric Hindrance and Molecular Structure Play Dominant Roles.

A tetrahedron-like guest molecule (THV) with four ditopic arms, consisting of viologen (V) and hexylene moieties, was synthesized, and its interaction with cucurbit[8]uril (CB[8]) was investigated. As a reference, the interaction between CB[8] and an analogue of the arm of the linear ditopic guest (LHV) was first explored by 1 H NMR and UV/Vis spectroscopy. In this case, CB[8] was located on the hexylene moiety and resulted in the formation of a binary complex. However, when THV interacted with CB[8], despite having four arms with four hexylene moieties, only two CB[8] molecules were identified as located on the hexylene moieties; the other two CB[8] molecules resided on the V moieties. Great steric hindrance among the arms played a dominant role in the interaction between THV and CB[8]. Regardless of whether the guest molecule was THV or LHV, CB[8] moved to its V moiety (electron-deficient part) to form the charge-transfer complex upon the addition of a stopper containing a naphthol residue (electron-rich part). Guests LHV and THV were reduced to LHV+(+.) and THV+4(+.) upon the addition of sodium dithionite. Dimerization of LHV+(+.) was enhanced when CB[8] was present in less than 0.5 equivalents. In contrast, dimerization was suppressed when CB[8] was present in more than 0.5 equivalents. However, the V+. units of THV+4(+.) stacked intramolecularly because of the tetrahedron-like molecular structure of THV. The influence of CB[8] on the dimerization of THV+4(+.) was weaker than that on LHV+(+.) .

Specific enrichment of a targeted nitrotyrosine-containing peptide from complex matrices and relative quantification for liquid chromatography–mass spectrometry analysis

Protein tyrosine nitration is considered an important non-enzymatic post-translational modification. In the tyrosine nitration process, 3-nitrotyrosine is formed and recognized as a biomarker of nitrosative/nitrative stress implicated in inflammatory responses and age-related disorders. In view of the complexity of biological samples and the ultra-low abundance of protein-incorporated nitrotyrosine, selective enrichment of nitrotyrosine-containing peptides prior to chromatographic separation is crucial. Herein, I report a simple yet highly specific and efficient enrichment method for nitrotyrosine-containing peptides. After blocking all primary amines in the sample by acetylation with acetic anhydride, I then further converted all nitrotyrosine residues into aminotyrosine residues by reduction with dithiothreitol and hemin. Therefore, I eliminated the side-product with 80Da adduct, since inevitable considerable amount of which was generated in the widely used reduction mediated by sodium dithionite. Both acetylation and reduction yields were close to 100%, and my one-pot sample derivatization applied no solid phase extraction steps or sample transference to avoid sample loss. To capture and release aminotyrosine-containing peptides, I synthesized an N-hydroxysuccinimide-ester-functionalized stationary phase which had very high affinity towards amino groups and possessed a base-cleavable ester linker to retrieve targeted peptides by hydrolysis. I validated this strategy by highly efficient enrichment of the targeted peptide from complex matrices of trypsin-digested bovine serum albumin (BSA) and human plasma spiked with derivatized nitrotyrosine-containing angiotensin II. My enrichment method successfully removed most untargeted peptides in those samples. By relative quantification with home-made identical and stable-isotope labelled internal standards, I investigated the recoveries of a nitrotyrosine-containing peptide from complex biological matrices during enrichment for the first time. Mean recoveries were 49.8% and 41.1% (n=6) for the enrichment of nitrotyrosine-containing angiotensin II from 1:100 (w/w) BSA digest and from 1:10 000 (w/w) human plasma digest, respectively. My enrichment method demonstrated great potential in future applications to clinical samples and biomarker discovery.