Potassium Hydrogen Phthalate Buffer Research Articles

Investigations of Nanoparticle Suspensions of Prussian Blue and Its Copper Analogue: Amine Functionalization and Electrochemical Studies

Prussian blue (PB) and its analogues are promising materials for electrochemical energy storage, yet their use in flow-type devices is limited by their lack of redox responsiveness as colloidal suspensions. We have investigated the redox chemistry amine functionalization of PB along with its Cu analogue (CuPBA). No redox response of colloidal PB was observed and suspensions of CuPBA formed films on electrode surfaces with and without applied potentials; the films were redox-active but the material that remained suspended in solution did not participate in redox chemistry. Propylamine (pa), ethylenediamine (en), or tetramethylethylenediamine (TMEDA) were added in an attempt to maintain well dispersed suspensions through nanoparticle surface functionalization. Propylamine modifications resulted in a loss of the CuPBA network and subsequent precipitation of insoluble materials. Coordination of ethylenediamine prompted the formation of Cu and Fe monomers ([Cu(en)2]m+/[Fe(CN)6]n-]) that remained soluble in aqueous electrolytes. In the absence of supporting electrolytes, these monomers formed a one-dimensional (1D) polymeric structure (Cu2Fe-1D). TMEDA modification preserved the CuPBA extended structure with only modest precipitate formation over 30 min. The redox responsiveness of these suspensions depended on conditions; in 1 M KCl, no redox chemistry was observed for the CuPBA. In pH 4 potassium hydrogen phthalate buffer, a signal was observed that was attributed to the Fe centers of CuPBA. Under these conditions, the material precipitated in ∼15 min and the signal was lost. Although the Fe centers in these networks are redox-active, additional work is needed to realize longer-term redox activity and stability. Ligand modifications can alter the properties of these networks but within a given ligand class, e.g., amines, the effects can vary greatly from the deconstruction of the framework to preventing film formation.

Development and Validation of Extractive Spectrophotometric Method for Estimation of Hydroxychloroquine Sulphate by using Smartphone Application

A simple, sensitive, accurate, precise and reproducible extractive spectrophotometric method was developed for estimation of Hydroxychloroquine Sulphate (HCQS) in bulk and pharmaceutical dosage form. The method is based on formation of ion pair complex of Hydroxychloroquine Sulphate with Bromocresol green dye in acidic medium. This complex extracted in chloroform and measured quantitatively at 421nm for estimation of Hydroxychloroquine Sulphate present in the sample. In this method estimation was also done by using Smartphone Application known as PhotoMetrix pro. Beer Lambert’s law obeyed over a range of 2-10 μg/ml for HCQS by UV spectrophotometric (r²=0.9988) and by SmartPhone Image analysis (r²=0.999) method. The developed method was successfully applied for estimation of Hydroxychloroquine Sulphate in three commercial product tablet dosage form without interference from common additives. The assay was found to be 100.09%, 100.8%, 98.6% by UV and 99.2%, 101.46%, 101.1% using PhotoMetrix for three formulation containing Hydroxychloroquine Sulphate. The developed method was also validated according to ICH Q2 guideline for linearity, range, accuracy, and precision. Comparison for both method UV and PhotoMetrix done by performing t-test, result shows that there is no significant difference between both method so PhotoMetrix can be used as alternative to UV for routine analysis of Hydroxychloroquine Sulphate.
 Keywords: Hydroxychloroquine Sulphate, Bromocresol green, Potassium Hydrogen Phthalate buffer, UV spectrophotometric, PhotoMetrix.

Enhancing the Sensitivity of GaN High Electron-Mobility Transistors-Based pH Sensor by Dual Function of Monolithic Integrated Planar Multi-Channel and Ultraviolet Light

In order to realize high-sensitivity real-time monitoring of acid–base neutral solutions in the industrial field, it is very important to study how to improve the sensitivity of a pH sensor. Herein, the sensitivity of the pH sensor was improved by using both monolithic integrated planar multi-channel and photoconductive properties of gallium nitride (GaN) high electron-mobility transistors (HEMTs) as a core of the pH sensor. The sensitive area of aluminum gallium nitride/gallium nitride (Al <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.25</sub> Ga <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.75</sub> N/GaN) heterojunction HEMT channel surface was increased, and the channel effective resistance was reduced by planar multi-channels. And the photogenerated current was generated by 365-nm ultraviolet (UV) light based on the photoconductive effect. This investigation mainly shows as the sensitivity of the tri-channel was 37.04 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu \text{A}$ </tex-math></inline-formula> /pH, which increased 30 times compared with that of the single-channel device under the dual action of planar multi-channel and 365-nm UV light coupling in potassium hydrogen phthalate, mixed phosphate, and borax pH correction buffer solutions. The concept of using the GaN HEMT-based pH sensor for direct quantification of pH values in waste water provides a simple and high-performance method for industrial applications.

LCST and UCST Transition of Poly(DMAEMA‐b‐MEO2MA) Copolymer in KHP Buffer

AbstractBlock copolymers of poly(2‐(dimethylamino)ethyl methacrylate) and poly(di(ethylene glycol) methyl ether methacrylate) (poly(DMAEMA‐b‐MEO2MA)) are successfully prepared by sequential reversible addition‐fragmentation chain transfer polymerization and evaluated its thermoresponsive behavior in acidic potassium hydrogen phthalate buffer. Individual block of the corresponding block copolymers exhibits lower critical solution temperature (LCST) transition whereas the synthesized block copolymers are found to exhibit dual thermoresponsive behavior: LCST at low temperatures due to the MEO2MA block and upper critical solution temperature (UCST) at high temperatures due to phthalate crosslinked protonated PDMAEMA block. The agglomeration at LCST is effectively enhanced by the ion–ion interactions within the chains. However, at higher temperature the hydrophobicity by the low hydration due to inter‐ionic interactions is disrupted at UCST, resulting in a transparent solution. The temperature‐dependent phase transition of the copolymer (i.e., from micelles to agglomerates, and reversibly to micelles) is confirmed using dynamic light scattering, UV–visible spectroscopy, and transmission electron microscopy. The unique dual thermoresponsive behavior upon heating and cooling cycles is found to exhibit very small hysteresis. The morphological transformation during LSCT and UCST‐type phase transition is explained via a proposed schematic illustration.

Efficient removal of bacteria from aqueous media with kaolinite and diatomaceous earth products.

To understand the relationships between physical and chemical parameters of kaolinite and diatomaceous earth, and their capacities to remove bacteria from aqueous media. To determine the optimal aqueous media parameters for use of these products in water disinfection processes. Seven kaolinite and three diatomaceous earth products were evaluated. Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Bacillus megaterium were used as proxy for bacterial pathogens. Fully calcined kaolin and amorphous diatomaceous earth demonstrated the highest extent and consistency in removing all the bacteria. The removal depended on ionic strength and pH of aqueous media with 100mmoll-1 pH 5 potassium hydrogen phthalate buffer revealing the highest (2 log per gram) extent of the removal. Al3+ cations enhanced sorption up to 4 log per gram. Calcined kaolin and amorphous diatomaceous earth are excellent sorbents for bacteria. Fully calcined kaolin and amorphous diatomaceous earth are perspective tools for wastewater and water disinfection against waterborne bacterial pathogens.

Development of Calibration and Standard Addition Polarographic Determination of Ascorbic Acid

Aims: Effect of pH on polarographic waves of ascorbic acid were studied by recording polarograms of ascorbic acid solution, between 0 to 400 mV at different pH (0.065 to 9.6) using 0.008% solution of gelatin and 0.05 M potassium hydrogen phthalate buffer (containing 0.25% oxalic acid) as maxima suppressor and supporting electrolyte respectively. Methods: Ascorbic acid is strong reducing agent and produces an anodic wave which shifts with pH. There is no significant change in height of wave with change in pH from 2.25 to 4.85. For determination of ascorbic acid pH 4.0 is chosen. Ascorbic acid present in synthetic sample is determined by calibration, external standard addition and internal standard addition methods. The results obtained are in good agreement with the quoted values. Result: The number of electrons taking part in the reversible reaction is found to be 2. The half-wave potential is found to be independent of the ascorbic acid concentration. peak current is proportional to the concentration of ascorbic acid in the range 10-6-10-3M and the reproducibility is better than ±1 per cent. Chloride and sulphur compounds, such as sulphides and thiols, do not interfere, and sulphite can be determined at the same time as the ascorbic acid. Some substituted phenols interfere but can often be detected by reversing the direction of polarisation. Reductones interfere but tin(II) and manganese(II) do not. A method has also been developed to determine ascorbic acid in the presence of an excess of iron. Different extraction media are discussed in terms of their influence on the redox potential of iron. Comparative titrimetric determinations of ascorbic acid in some fruits, vegetables and beverages gave higher results than the voltammetric method (6). A polarographic study of the oxidation mechanism of L-ascorbic acid and of the reduction mechanism of dehydro-L-ascorbic acid was carried out in an acid medium. For L-ascorbic acid, the oxidation process involves a two electron transfer. The polarographic curve shows that the limiting current is governed by diffusion. On the rising portion of the wave, the two electron oxidation process consists of two consecutive one electron transfers, the second being the rate determining step. The reaction orders, together

Cadmium determination in phosphate fertiliser using a PAN-Nafion® modified glassy carbon electrode by stripping voltammetry

A simple method for the determination of trace cadmium (Cd) (II), using a disposable 1-(2-pyridylazo)-2-naphthol [PAN]-Nafion®-coated glassy carbon electrode, has been developed. The modified electrode exhibited a significant improvement on both sensitivity and selectivity for Cd (II) determination, compared with a bare glassy carbon electrode (GCE), a PAN-coated GCE (PAN-GCE), and a Nafion®-coated GCE (Nafion® GCE). Differential pulse anodic stripping voltammetry (DPASV) was performed, in 0.05 M potassium hydrogen phthalate (KHP) buffer medium, after Cd (II) ion accumulation. The Cd(II) ion accumulated on the PAN-Nafion® surface of the glassy carbon working electrode through the formation of a chemical complex at an open circuit. The modified GCE with Cd (II) complex was then transferred to a 0.1 M KI solution and subjected to an electrochemical stripping procedure. Cyclic voltammetry (CV) was employed to confirm the successful stepwise assembly procedure for the modified electrode. The structure of PAN-Nafion® on the surface-modified electrode was characterised by scanning electron microscopy (SEM). System variables were optimised to yield the most suitable conditions, including the pH and concentration of the accumulation medium, deposition potential, deposition time, and amount of coated PAN-Nafion®. The quantitative analysis of contaminated cadmium in phosphate fertiliser samples was performed. The results obtained from the proposed method agree well with those obtained by inductively coupled plasma-optical emission spectrophotometry (ICP-OES).

A study of mercury(II)-catalysed substitution of cyanide in hexacyanoferrate(II) by 2-methylpyrazine: effects of inhibitor on the catalysed reaction

The kinetics and mechanism of the mercury(II)-catalysed ligand substitution reaction between potassium hexacyanoferrate(II) and 2-methylpyrazine (2-Mepz), in potassium hydrogen phthalate buffer of pH 3.50 ± 0.02 at 25.0 ± 0.1 °C and constant ionic strength of 0.1 M, were studied spectrophotometrically by measuring the absorbance of the yellow-coloured product at 447 nm (λmax). The reaction was studied under pseudo-first-order conditions using excess of 2-Mepz. The reaction was found to obey first-order dependence in concentration of both [Fe(CN)6]4− and 2-Mepz. At higher concentrations of 2-Mepz, the effect of [2-Mepz] levels off. A complex behaviour is observed on varying [Hg2+]. The effect of pH on the reaction rate was also analysed. The effects of dielectric constant and water content of the reaction medium have been interpreted in terms of the formation of a polar activated complex and suggest an Id mechanism. The inhibitory effect of 2,3-dimercaptopropanol on the reaction was also studied and explained in terms of binding of this species to the catalyst.

Spectroscopic and Substitution Kinetic Studies of Hexacyanoferrate(II) Complexes byEDTA Catalysed with Mercury(II)

Kinetics and mechanism of substitution of cyanide ion in hexacyanoferrate(II) by EDTA catalysed by mercury(II) has been studied spectrophotometrically at 365 nm in potassium hydrogen phthalate buffer of pH = 5.0 and ionic strength, I = 0.1 M, maintained by (KNO3) at 25 °C. Effect of the pH and concentration of the EDTA, [Fe(CN)4-6] on the rate of reaction has been studied. The kinetics and mechanism of the reaction has been shown through dissociative mechanism. The mechanism of ligand substitution in the complex together with the kinetic data has been shown. The catalytic activity of mercury(II) has also been studied as a function of its concentration. The maximum reaction product was detected at pH = 5 after which a decline in absorption occurs followed by precipitation. It is an inexpensive method to identify and remove the cyanide ion in solution even in very low concentration of the order of 10-4 M.

Photocurrent and photoelectrochemical hydrogen production with tin porphyrin and platinum nanowires immobilized with nafion on glassy carbon electrode

Platinum nanowires mixed with Tin meso-tetra (4-pyridyl) porphine dichloride and nafion solution was used to modify the surface of glassy carbon electrode for photocurrent generation and photo-electrochemical hydrogen production. Different concentrations of porphyrin (50 μM, 100 μM, 300 μM and 500 μM) and platinum loading (200 μg/cm 2, 400 μg/cm 2, 600 μg/cm 2 and 800 μg/cm 2) were tested at −150 mV Vs Ag/AgCl in reaction cell containing the modified glassy carbon electrode as working electrode, platinum wire as counter electrode and Ag/AgCl as reference electrode, under illumination to determine the optimum, based on photocurrent production in 50 mM potassium hydrogen phthalate buffer (pH 3) containing 0.1Na 2SO 4 as supporting electrolyte. Optimum photocurrent was obtained at 100 μM tin porphyrin and 600 μg/cm 2 platinum loading. Detectable amount of hydrogen was produced at −350 mV Vs Ag/AgCl under irradiation with visible light.

Synthesis, characterization and electrocatalytic properties of FeCo alloy nanoparticles supported on carbon nanotubes

FeCo alloy nanoparticles with diameters about 18 nm were synthesized by wet chemical technique, which were characterized by transmission electron microscopy (TEM), X-ray powder diffraction (XRD), high-resolution transmission electron microscopy (HRTEM) and energy-dispersive X-ray spectrometry (EDX). XRD analysis indicates that the FeCo alloy nanoparticles supported on the surface of carbon nanotubes (CNTs) have body-centered cubic (bcc) phase. TEM images show that the FeCo alloy nanoparticles are in the shape of spheroid on the outer surface of the carbon nanotubes. The electrochemical behavior of film of FeCo/CNT nanocomposites was studied on a glassy carbon (GC) electrode. The cyclic voltammetry results indicate that the FeCo/CNT nanocomposites film-modified GC electrode shows highly electrocatalytic activity toward hydrogen peroxide reduction in the potassium hydrogen phthalate buffer solution, and the electrocatalytic behavior is attributed to the expected catalytic activity of nanosized FeCo alloy nanoparticles supported on the external walls of carbon nanotubes.

Fluorescence enhancement effect for the determination of curcumin with yttrium(III)—curcumin—sodium dodecyl benzene sulfonate system

It is found that the fluorescence of curcumin is greatly enhanced by yttrium(III) (Y 3+) in the presence of sodium dodecyl benzene sulfonate. Based on this, a sensitive fluorimetric method for the determination of curcumin in aqueous solution is proposed. In the potassium hydrogen phthalate (KHP) buffer, the fluorescence intensity of curcumin is proportional to the concentration of curcumin in the range of 7.37×10 −4–0.18, 0.18–2.95 μg mL −1 and the detection limit is 0.1583 ng mL −1. The actual samples are satisfactorily determined. In addition, the interaction mechanism is also studied.

Study of the interaction of CTZAMB–Cu(II) with DNA and the determination of DNA

In this paper, the electrochemical behavior of the CTZAMB–Cu(II) complex with DNA has been investigated in potassium hydrogen–phthalate buffer solution (pH 2.5). In the absence of DNA, there was a sharp reduction peak in the single sweep polarogram due to the presence of CTZAMB–Cu(II), while in the presence of DNA this peak decreased in a quantitative fashion. This decrease in peak current is due to the formation of the CTZAMB–Cu(II)–DNA complex. Under the optimum conditions, the decrease of peak current is linear with DNA concentration in the range from 3.0 × 10 −7 to 7.0 × 10 −6 g ml −1, and the detection limit is 1.0 × 10 −7 g ml −1. This new method exhibits a good recovery and sensitivity, which could be applied to the determination of DNA in real samples. The mechanism of the interaction of DNA and CTZAMB–Cu(II) is also discussed.

Orthophosphate, phytate, and total phosphorus determination in cereals by flow injection analysis.

A flow injection spectrophotometric procedure with enzymatic hydrolysis was developed for determination of orthophosphate, phytate and total phosphorus in cereal samples. Phosphorus species were extracted from cereals with 0.05 mol L(-1) potassium hydrogen phthalate buffer solution at pH 5.7. Orthophosphate was directly determined in the extracts by molybdenum blue spectrophotometric method. The phytate was hydrolyzed by the enzyme phytase coupled to a solid phase packed into an enzymatic reactor, and the resulting hydrolyzed orthophosphate was also determined by spectrophotometry at 650 nm. After optimization for phosphorus species extraction and enzymatic hydrolysis, a linear calibration graph was obtained up to 196 x 10(-6) mol L(-1) orthophosphate (P conc = -2.67 + 0.52x, r = 0.9998). Measurements are characterized by relative standard deviation of 1.6% for a standard of 72 x 10(-6) mol L(-1) orthophosphate and no baseline drift was observed during 4 h operation periods. It provides 72 measurements per hour, with 2.4 x 10(-)6) mol L(-1) and 7.9 x 10(-6) mol L(-1) as detection and quantification limits, respectively.

Kinetics and mechanism of exchange of cyanide in hexacyanoferrate(II) by N-methylpyrazinium ion in the presence of mercury(II) as a catalyst

The kinetics of the mercury(II) catalysed ligand exchange of the hexacyanoferrate(II) complex with the N-methylpyrazinium ion (Mpz+) in a potassium hydrogen phthalate buffer medium has been investigated at 25.0 ± 0.1 °C, pH = 5.0 ± 0.02 and ionic strength, I = 0.1 M (KNO3). The reaction was followed spectrophotometrically in the aqueous medium by measuring the increase in absorbance of the intense blue complex [Fe(CN)5Mpz]2− at its λmax 655 nm. The effect of pH, and the concentrations of [Fe(CN)64−] and Mpz+ on the reaction rate have been studied and analysed. The varying catalytic activity of mercury(II) as a function of concentration has also been explained. The kinetic data suggest that substitution follows an interchange dissociative (Id) mechanism and occurs via formation of a solvent-bound intermediate. The effects of the dielectric constant of the medium on the reaction rates have been used to visualize the formation of a polar activated complex and an interchange dissociative mechanism for the reaction. A mechanism has been proposed in order to interpret the kinetic data. Kinetic evidence is reported for the displacement of CN− by Mpz+ in [Fe(CN)64−]. Activation parameters for the catalysed and uncatalysed reaction have been evaluated, and lend further support to the proposed mechanism.

Introducing the primary pH-metric standardization in nonaqueous solvents of extremely high permittivities: behaviour of the potassium hydrogen phthalate buffer in formamide, and acquisition of an appropriate salt bridge for pH measurements

The primary pH-metric standardization, in compliance with the IUPAC guidelines is, for the first time, introduced in the domain of nonaqueous media of extremely high permittivities. In this context the primary standard pH PS values for the potassium hydrogen phthalate buffer in formamide have been determined over a range of temperatures, based on the potential difference measurements of Harned's cell. The found pH PS values decrease slightly with increasing temperature in the range 283–323 K according to: pH PS =7.9538−0.008093×(T ( K))+0.0000100×(T 2 ( K)) . Furthermore, to make the operational cell for pH measurements applicable to the present medium, a suitable equitransferent salt bridge (NH 4Cl in formamide) has been characterized by the method of the concentration cell with transference.

Medium effects, comparability and predictability of pH-standards in aqueous+organic solvent mixtures: behavior of the (ethylene carbonate+water) and (propylene carbonate+water) systems

From the potential difference measurements of the reversible buffered cells Pt ∣ H 2 ∣ KHPh+KCl ∣ AgCl ∣ Ag ∣ Pt and Pt ∣ H 2 ∣ KHPh+KCl ∣ Hg 2Cl 2 ∣ Hg ∣ Pt in (propylene carbonate+water) and (ethylene carbonate+water) solvent mixtures, respectively, primary pH-metric standards pH PS based on the potassium hydrogen phthalate buffer (KHPh) have been determined. This is the first time that this type of standard is acquired for water mixtures with aprotic organic cosolvents nearly isodielectric with water. The pH PS results at the various solvent compositions are interpreted through the function (pH PS+ E°/ k), where E°=standard potential difference, and k=ln 10 RT/ F, in terms of the primary medium effects upon HCl and the single ions H + and Cl −.

Ionization Constants of o-Phthalic Acid and Standard pH Values of Potassium Hydrogen Phthalate Buffer Solutions in Glycerol + Water Solvent Mixtures at Normal and Subzero Temperatures

Determination of primary standards for pH measurements in glycerol + water solventmixtures has been carried out based on reversible emf measurements of the cellPt|H2|KHPh (m PS) + KCl (m Cl)|AgCl|Ag|Ptwhere KHPh denotes the potassium hydrogen phthalate buffer solution of molalitym PS = 0.05 mol-kg−1, at glycerol mass fractions w G = 0.2 and 0.4, within thetemperature range −10 to 40°C. A multilinear regression procedure as a functionof electrolyte molality, glycerol mass fraction w G, and temperature T has beenapplied for the data processing leading to the values of primary standards pHPS.These can be represented by the following regression equationpHPS = (4.007037±0.001113) + (3.55844±0.01776)x G+(0.39622±0.01410)z + (4.3084±0.3377)z 2− (50.66±10.53)x G z 2 + (457.10±78.48)x G 2 z 2where z = (T − 298.15)/298.15. Parallel values of the first ionization constantof o-phthalic acid (H2Ph; benzene-1,2-dicarboxylic acid, the parent acid of KHPh),which are essential for the above calculations, have been determined fromreversible emf measurements of the cellPt|H2|H2Ph (m 1) + KHPh (m 2) + KCl (m 3)|AgCl|Ag|Ptover the range of solvent composition and temperatures mentioned above.

Functional-group effects on the ion-exchange properties of organically modified silicates

The ion-exchange and permselectivity of organically modified silicate films prepared from 3-aminopropyltriethoxysilane (APTEOS) have been investigated as a function of film structure and functionality. In this study, APTEOS was hydrolyzed and co-polymerized with either isobutyltrimethoxysilane (BTMOS), phenyltrimethoxysilane (PTMOS), methyltrimethoxysilane (MTMOS), or tetramethoxysilane (TMOS), and the resultant hybrid sol spin cast on the surface of a glassy carbon electrode. The magnitude and rate of the ion-exchange and permselectivity of the modified electrode in pH 4, 0.05 M potassium hydrogen phthalate (KHP) buffer solutions of potassium ferricyanide (Fe CN 6 3− ) and ruthenium hexaammine (Ru NH 3 6 3+ ) were evaluated via cyclic voltammetry and visible spectrophotometry. In a 1 mM Fe CN 6 3− solution, the organically modified silicate films showed a ca. 4–10 fold increase in Faradaic current (relative to a bare electrode) after 10–120 min, whereas the voltammetric response of 1 mM Ru NH 3 6 3+ was completely or nearly completely suppressed. The magnitude and rate of ion-exchange and permselectivity depend strongly on the amount of ion-exchange sites and the type of modifier introduced into the material. Films prepared from APTEOS and either PTMOS or BTMOS showed significantly faster ion-exchange relative to films prepared with either TMOS or MTMOS, presumably due to a more open silicate framework. In terms of both ion-exchange and permselectivity, films prepared with a 1 : 1 mole ratio of modifier to APTEOS provided the best results.

Adsorption of Alginic Acid and Chondroitin Sulfate-A to Amine Functionality Introduced on Polychlorotrifluoroethylene and Glass Surfaces

The amine functionality is introduced onto a glass surface by using 3-(aminopropyl)-triethoxysilane (3-APTS)-a silane coupling agent-as well as by the adsorption of poly(L-lysine). The amine functionality is introduced onto the hydroxyl-functionalized polychlorotrifluoroethylene surface (PCTFE-OH) using 3-APTS as well. The amine-functionalized surfaces were thoroughly characterized by X-ray photoelectron spectroscopy (XPS). Selected polysaccharides, involved in fouling processes, such as alginic acid and chondroitin sulfate-A were allowed to adsorb onto amine-functionalized surfaces. It is shown that alginic acid adsorbs from calcium-free artificial seawater onto amine-functionalized glass surface prepared by the adsorption of poly(L-lysine) and onto amine-functionalized polychlorotrifluoroethylene surfaces (PCTFE-NH 2 ), The adsorption of alginic acid to PCTFE-NH 2 is very rapid, resulting in high-affinity isotherms and ∼5 A thick dry overlayer of the polysaccharide. In addition, we observe that the adsorbed alginic acid protects the PCTFE-NH 2 surface from hydrolysis by phosphate buffer 2 and from hydrolysis/oxidation by copper(II) acetate monohydrate solution. It is also shown that chondroitin sulfate-A adsorbs from potassium hydrogen phthalate buffer to the amine-functionalized glass surface prepared by the reaction between silanol groups on glass and 3-APTS. It is observed that alginic acid and chondroitin sulfate-A do not adsorb to the unmodified glass surface, which is polar and negatively charged, and the PCTFE surface, which is nonpolar, from aqueous solutions under various solution conditions. This study clearly indicates the importance of surface functional groups on the adsorption of polysaccharides, an important preliminary step in the biofouling of surfaces.