Microphase Adsorption-spectral Correction Research Articles

Interaction between Coomassie brilliant blue G250 and octylphenol polyoxyethylene ether (10) in aqueous solution

ABSTRACTThe characteristic absorption peak of Coomassie brilliant blue G250 (CBBG250) has obvious redshift phenomenon by the addition of octylphenol polyoxyethylene ether (10) (OP-10) in aqueous solution, which shows that there is interaction between CBBG250 and OP-10. Two physical models are described and applied to the study of the interactions of CBBG250 with OP-10. According to the microphase adsorption-spectral correction (MPASC) technique, CBBG250 can be adsorbed on a surfactant by electrostatic force, and the aggregation obeys the Langmuir isotherm. The adsorption constant and the maximum binding ratio of the aggregates are calculated to be B = 4.32 × 105 L/mol and N = 0.137, respectively. The surfactant-dye association interaction (SDAI) model believes that there is significant association interaction between the CBBG250 and nonionic surfactant OP-10 in aqueous solutions, and a series of thermodynamic parameters such as K, , and are also determined. The simulation results indicate that the two models can fit the experimental data very well.

Study on the Langmuir Aggregation of Sodium Octanesulfonate on Human Serum Albumin

The microphase adsorption-spectral correction (MPASC) technique was described and applied to the study of the interactions of sodium octanesulfonate (SOS) with human serum albumin (HSA). The aggregation SOS obeys the Langmuir monolayer adsorption. The results show the adsorption ratio of sodium octanesulfonate to HSA is SOS:HSA=18:1.The adsorption constant is K(SOS-HSA)=4.03 × 10(2). The detection limit is 0.036μmol/L. FT-IR spectra proved the binding changed the conformation of HSA.

Study on the Langmuir aggregation of fluorinated surfactants on protein

The microphase adsorption-spectral correction (MPASC) technique was described and applied to the study of the interactions of fluorinated surfactants such as potassium perfluorooctanesulfonate (PFOS) and potassium perfluorobutanesulfonate (PFBS) with human serum albumin (HSA). Sodium octanesulfonate (SOS) was also studied as non-fluorinated surfactant. The aggregation of PFOS, PFBS and SOS obeys the Langmuir monolayer adsorption. The results show that the adsorption ratios of surfactants to HSA are PFOS:HSA = 120:1, PFBS:HSA = 205:1 and SOS:HSA = 18:1. The adsorption constants are K PFOS–HSA = 5.01 × 10 3, K PFBS–HSA = 9.79 × 10 2 and K SOS–HSA = 4.03 × 10 3. The detection limits are 2.7 mg/L for BSA using PFOS, 3.1 mg/L using PFBS and 3.1 mg/L using SOS. It was found that fluorinated surfactant exhibited stronger interaction with protein than hydrogenated one, and fluorinated surfactant with long hydrophobic chain exhibited stronger interaction with protein than that with short hydrophobic chain.

Interaction of Trypan Blue with Protein and Application

AbstractThe microphase adsorption ‐ spectral correction (MPASC) technique has been described and applied to the aggregation of trypan blue (TB) in proteins. The formation of the microelectrostatic field in protein causes the Langmuir monolayer aggregation of TB. The adsorption ratio of TB to bovine serum albumin (BSA), ovalbumin (OVA), hemoglobin (Hb) and human γ‐globulin (γ‐G) was determined to be 14.8, 8.4, 2.8 and 27.6, respectively, and the adsorption constant of the aggregates to be 7.17 × 105, 4.88 × 106, 4.85 × 106 and 2.99 × 106. The adsorption ratio of TB to proteins interestingly indicates almost no relation to the array sequence of amino acid residues. The interaction of TB with proteins is sensitive at pH 3.29, and the reaction was applied to the determination of protein trace with satisfactory results.

Langmuir Aggregation of Thionin on Sodium Dodecyl Sulfate and Its Application

The microphase adsorption–spectral correction (MPASC) technique was applied to the interaction of thioin (TN) with sodium dodecyl sulfate (SDS) at pH 4.56. The synergism mechanism of SDS in solution was analyzed and discussed. The great electrostatic aggregation of TN on SDS obeys Langmuir monolayer adsorption. The property constants of the aggregate were determined and the quantitative determination of the anionic surfactant (AS) in samples was made in the presence of EDTA. Results showed that the large micellar aggregate is (TN–SDS2)31, the adsorption constant of the monomer aggregate is 1.85 × 105 (18°C), and its molar absorptivity is 4.45 × 106 L mol–1 cm–1. For analysis of samples, the recovery is between 94.5 and 111% and the RSD is less than 7.62%.

Langmuir Aggregation of Chromophore in Biomacromolecule and its Application: Interaction of Picramine CA (PCA) with Proteins

The microphase adsorption-spectral correction (MPASC) technique has been described. The formation of microelectrostatic fields in macromolecule is proposed and it causes the aggregation of a chromophore in protein. We have studied the interaction of picramine CA (PCA) with five proteins: bovine serum albumin (BSA), human n -globulin ( n -G), bovine hemoglobin (Hb), horse myoglobin (Mb) and ovalbumin (OVA). Results show that at pH 2.21, the adsorption ratios of PCA to BSA, n -G, Hb, Mb and OVA are 46, 54, 35, 15 and 21, respectively, their adsorption constants 3.17 ‐ 10 5 , 6.58 ‐ 10 4 , 1.40 ‐ 10 5 , 8.99 ‐ 10 4 and 1.68 ‐ 10 5 and their absorptivities 3.56 ‐ 10 5 , 3.06 ‐ 10 5 , 2.91 ‐ 10 5 , 1.10 ‐ 10 5 and 1.97 ‐ 10 5 l mol m 1 cm m 1 at 630 nm. The analysis of samples has given the satisfactory result.

Langmuir aggregation of azocarmine B on cetyl trimethylammonium bromide and application

The microphase adsorption-spectral correction (MPASC) technique was described and applied to the study of the interaction of azocarmine B (ACB) with cetyl trimethylammonium bromide (CTAB). The synergism mechanism of CTAB was analyzed and discussed. The adsorption of ACB on CTAB at pH 9.2 obeys the Langmuir monolayer adsorption. The great electrostatic micellar aggregate (ACB·CTAB3)26 was formed, on which the Cu–ACB complex was formed rapidly in the aggregate formula (Cu·ACB·CTAB3)26. The adsorption constant of the CTAB–ACB aggregate and the stability constant of the Cu–ACB complex was determined to be 3.45 × 10 5 and 7.71 × 10 5 , respectively. The analysis of the samples gave the satisfactory quantitative results. © 2002 Elsevier Science B.V. All rights reserved.

Langmuir aggregation of Evans blue on cetyltrimethylammonium bromide and on proteins and its application

The microphase adsorption-spectral correction (MPASC) technique is described and applied to the study of the interactions of Evans blue (EB) with cetyltrimethylammonium bromide (CTAB) and with four proteins: bovine serum albumin (BSA), myoglobin (Mb), hemoglobin (Hb) and ovalbumin (OVA). EB can be adsorbed on a cationic surfactant and on protein by electrostatic force and the aggregation obeys the Langmuir isotherm. Results have shown that the products are formed as follows: monomer aggregate EB·CTAB, micellar aggregate (EB·CTAB) 78 and protein aggregates (EB 68·BSA), (EB 14·OVA), (EB 126·Mb) and (EB 58·Hb). The adsorption constant of the aggregates are calculated to be K EB·CTAB=2.95×10 6, K EB68·BSA=3.40×10 4, K EB14·OVA=5.20×10 2, K EB126·Mb=6.81×10 2 and K EB58·Hb=5.73×10 2, respectively. The aggregation of EB in proteins is sensitive in the presence of CTAB and selective in the presence of EDTA and it has been applied to the analysis of samples with satisfactory results.

Langmuir Aggregation of Stain on Ionic Surfactant and its Application: Interaction of Bromo‐Pyrogallol Red with Cetyl Trimethylammonium Bromide (CTAB) and Determination of Molybdenum Traces

AbstractThe microphase adsorption‐spectral correction (MPASC) technique was de scribed and applied to study the interaction of bromo‐pyrogallol red (BPR) with cetyl trimethylammonium bromide (CTAB). The synergism mechanism of micelles was analyzed and discussed. The large electrostatic micelle adsorbs the chromophore in only the monolayer, and the adsorption obeys the Langmuir adsorption. The formation of the (BPR2·CTAB)78 aggregate accelerates the Mo‐BPR complex reaction. Experimental results showed the adsorption constant of the adsorption aggregate 6.20 × 105 and its molar absorptivity ϵr610nm = 1.40 × 106 lmol−1cm−1. For analysis of samples, the recovery of Mo was between 97.4 and 107% and the RSD was less than 4.39%.

Langmuir Aggregation of Fluorescein Isothiocyanate (FITC) on Cetyl Trimethylammonium Bromide (CTAB) and Application to Determination of Anionic Detergent in Sewage

The microphase adsorption - spectral correction (MPASC) technique was described and applied to study the interaction of fluorescein isothiocyanate (FITC) with cetyl trimethylammonium bromide (CTAB). The synergism mechanism of micelle was analyzed and discussed. The aggregation of FITC on CTAB obeys the Langmuir monolayer adsorption. Results showed that the monomer and micellar aggregate is FITC-CTAB 3 and (FITC-CTAB 3 ) 2 9 , respectively at pH 9.62. The adsorption constant of the CTAB-FITC aggregate was determined to be 2.10 x 10 5 . Interestingly, it was observed for the addition of an anionic surfactant to desorb FITC from its CTAB aggregate and this has been applied to the quantitative determination of trace amounts of anionic detergent (AD) in sewage.

Langmuir Aggregation of Bordeaux R on a Cationic Surfactant and Its Application to Sensitive Quantitative Determination of Copper

The microphase adsorption-spectral correction (MPASC) technique has been applied to the study of the interaction between cetyl trimethylammonium bromide (CTMAB) and the dye Bordeaux R (BR) at pH 9.6. The aggregation of BR on the CTMAB surface obeys the Langmuir adsorption isotherm. The aggregation of BR on CTMAB accelerates the complexation between Cu(II) and BR. Results at 25°C show that the adsorption constant of the CTMAB–BR 1:1 aggregate is 6.80 × 104. In the presence of CMTAB, the Cu–Br complex with a mole ratio of 2:1 has a cumulative stability constant of 1.08 × 1011. The cooperative adsorption and complexation have been applied successfully in a sensitive determination of trace amounts of copper.

Production and Application of the Langmuir Aggregates of Eosine with Cetyl Trimethyl Ammonium Bromide

The procedure of microphase adsorption–spectral correction is applied to the interaction of eosine Y (EO) to the micelles of cetyl trimethyl ammonium bromide (CTAB). The Langmuir aggregation of EO on CTAB occurs owing to microelectrostatic attraction. The results have shown that at pH 3.8, monomeric and micellar aggregates have the structure EO5·CTAB2 and (EO5·CTAB2)39. The adsorption constant of an aggregate is 7.01·105, its molar absorption coefficient is e = 8.8·104 liters·mole−1·cm−1 at 550 nm. Application of the aggregation of EO on CTAB gives satisfactory results for quantitative determination of cation surface‐active agents (surfactants).

Langmuir Aggregation of Coomassie Brill Blue on Protein and Determination of Protein by MPASC

The microphase adsorption–spectral correction technique (MPASC) has been applied to investigate the aggregation of coormassie brill blue G250 (CBBG) on protein in which the microelectrostatic fields exist. The Langmuir adsorption of CBBG in protein was confirmed, and the interaction is sensitive at pH 3.78. Results show that the adsorption ratio of CBBG to five proteins, e.g., BSA, OVA, Hb, Mb and γ-G are 100, 65, 30, 98 and 210, respectively, their adsorption constants are 9.92 × 104, 8.04 x 104, 9.38 × 104, 1.66 × 105, and 2.75 × 104, and their absorptivities are 2.33 × 106, 1.56 × 106, 1.98 × 106, 5.61 × 105, and 4.48 × 106 Lmol–1 at 670 nm. The study indicates that 1 mg of protein adsorbs about 1.54 mmol of CBBG. For the protein determination of samples, the recovery of protein is between 88.0 and 111% and the relative standard deviation is 2.6%.

Study of the spectrophotometric analysis of protein solution with p-iodochlorophosphonazo as adsorbate by the microphase adsorption-spectral correction technique.

A microphase adsorption-spectral correction (MPASC) technique was established, which consists of Langmuir adsorption and the spectral correction technique. The hypothesis of a microelectric field formed in macromolecules is proposed, the existence of which results in the adsorption and aggregation of dye molecules in macromolecules. This paper describes the spectrophotometric analysis of protein solution with p-iodochlorophosphonazo (p-ICPA) dye. The results showed that the adsorption ratios of p-ICPA to proteins (bovine serum albumin, ovalbumin, myoglobin and gamma-globulin) at pH 2.56 were 54, 25, 14 and 90, respectively, their adsorption constants 2.86 x 10(5), 1.42 x 10(6), 2.38 x 10(5) and 1.09 x 10(5) and their absorptivities 8.00 x 10(5), 4.02 x 10(5), 1.77 x 10(5) and 1.15 x 10(6) l mol-1 cm-1 at 620 nm. The analysis of practical samples showed that the recovery of protein was between 92.3 and 108% and the relative standard deviation was 4.7%.