Methylene Blue Method Research Articles

Biosurfactant Production by Rhizospheric Bacteria Isolated from Biochar Amended Soil Using Different Extraction Solvents

Microbial-derived surface-active compounds (biosurfactants) have attracted attention due to their low toxicity, cost-effectiveness, biodegradable nature and environment compatibility. Due to paucity of knowledge in the production of biosurfactant by microorganisms from other sources such as biochar-amended soil, the present study investigates the potential of rhizospheric bacteria isolated from biochar amended soil of okra plant in the production of biosurfactants using different recovery techniques. Rhizospheric bacteria were screened for biosurfactant production using Haemolytic, Oil spreading, Drop collapse, Methylene blue method, Bacterial adhesion to hydrocarbon and Emulsification activity. The biosurfactant was extracted using different extraction solvents (acid precipitation, ethyl acetate, acetone, dichloromethane and chloroform/methanol). Degradation of hydrocarbon (diesel) was determined spectrophotometrically. A total of twenty-three rhizospheric bacteria were isolated from the soil of Abelmoschus esculentus (okra plant). Nine isolates were positive for haemolysis with values between 1.1±0.2 mm by Enterobacter cloaca and 23.0±0.6 mm by Alcaligenes faecalis. Two isolates were positive for the drop collapse test. Only one isolate was positive for the methylene blue method. In the oil spreading test, ten isolates were positive and five isolates had the ability to adhere to hydrocarbons. Six isolates exhibited emulsification potential after 24 h, with the highest and lowest (65.9%) and (40.7%) recorded by Alcaligenes faecalis and Citrobacter sp, respectively. The biosurfactant produced by Alcaligenes faecalis using different recovery solvents showed that chloroform and methanol are the best extraction solvents and Alcaligenes faecalis was also able to degrade diesel oil over a period of 10 d. Conclusively, Alcaligenes faecalis recovered from soil amended sawdust biochar of okra plant is both a potent biosurfactant producer and an agent for remediating hydrocarbon-contaminated soil environments.

Probing structural variations of graphene oxide and reduced graphene oxide using methylene blue adsorption method

Recently, graphene oxide (GO) and reduced graphene oxide (rGO) have drawn significant attention in the development of gas sensors and nanocomposites. However, random distribution of oxygen functionalities in GO and rGO limits the use of these materials in the above application. In this study, methylene blue (MB) adsorption onto GO, synthesized under different oxidative conditions, and onto corresponding rGO was looked into in detail as both have high affinity towards MB. Our results show the amounts of MB adsorbed onto all GOs are the same irrespective of the time of oxidation. However, significant changes were observed in the amount of MB adsorbed on the corresponding rGOs that have been thermally reduced. Further, the FT-IR spectroscopic data show a blue shift for C=C stretching vibrations of MB adsorbed onto GO, whereas a red shift is observed for the bands assigned to stretching vibrations of C–N and CH3 bending upon adsorption on rGO. The above observations suggest complex structural geometry of GO and rGO, especially with respect to the spatial distribution of oxygen functionalities and their propagation during synthesis that influence MB adsorption, and its orientation. Thus, the information provided will be important in controllable synthesis of both GO and rGO with large surface area for the above applications as well as in applications such as water purification and photocatalysis.

Adsorption of Pb (II) ions by activated and modified candlenut shell based carbon

A research on the adsorption of Pb2+ ions by candlenut shell carbon that was activated with 10% ZnCl2 and then modified with HNO3 has been done. The candlenut shell was carbonized at 400°C before activation and surface modification. Characterization of the carbon was carried out by surface area test using methylene blue method, identification of functional groups using Fourier Transform Infrared (FTIR) and adsorption experiment at optimum condition. The concentration of Pb (II) ions was determined by Atomic Absorption Spectrophotometer (AAS). Surface area of carbon, activated carbon and modified activated carbon are 503.57 m2/g, 516.63 m2/g and 524.86 m2/g, respectively. Boehm titration and FTIR analysis results showed that functional groups such as -OH (in carboxylic acid and phenol) and C=O (in lactone) increased after modification with HNO3. Based on analysis using AAS, the optimum adsorption time was 30 minutes and the optimum pH was 4. The adsorption capacity of Pb2+ ions by modified activated carbon was higher than un-modified activated carbon.

Adsorption of chromium ions by candlenut shell based carbon activated with H3PO4

Candlenut shell based carbon which was chemically activated using a solution of phosphoric acid and modified with nitric acid has been used to adsorb chromium ions (Cr(VI)). This study aims to examine the effect of phosphoric acid activation on the surface area of the candlenut shell carbon and the effect of nitric acid on the adsorption capacity of metal ions Cr (VI). The study was carried out by activating the candlenut carbon with 10% phosphoric acid for 24 hours then modified with 6 N nitric acid for 24 hours. The activated carbon that has been modified is then optimized with several parameters, namely time, pH and the number of adsorbents to maximize the performance of activated carbon. The surface area of candlenut based activated carbon was determined by methylene blue method and the adsorption capacity was measured using Atomic Absorption Spectrophotometer (AAS). The results showed that the carbon surface area before and after activation increased from 1557.3 m2/g to 1669.5 m2/g, respectively, and the surface area increased dramatically after HNO3 modification to 2090,8 m2/g. The adsorption capacity to the metal ions (Cr(VI)) tends to follow the Langmuir isotherm model which is equal to 20.4 mg/g.

Emissions of ammonia and hydrogen sulfide from typical dairy barns in central China and major factors influencing the emissions

There are few studies on the concentrations and emission characteristics of ammonia (NH3) and hydrogen sulfide (H2S) from Chinese dairy farms. The purpose of this study was to calculate the emission rates of NH3 and H2S during summer and to investigate influencing factors for NH3 and H2S emissions from typical dairy barns in central China. Eleven dairy barns with open walls and double-slope bell tower roofs from three dairy farms were studied. Five different locations in each barn were sampled both near the floor and at 1.5 m above the floor. Concentrations of NH3 and H2S were measured using the Nessler’s reagent spectrophotometry method and the methylene blue spectrophotometric method, respectively. NH3 concentrations varied between 0.58 and 4.76 mg/m3 with the average of 1.54 mg/m3, while H2S concentrations ranged from 0.024 to 0.151 mg/m3 with the average of 0.092 mg/m3. The concentrations of NH3 and H2S were higher during the day than at night, and were higher near the ground than at the height of 1.5 m, and were higher in the manure area than in other areas. NH3 and H2S concentrations in the barns were significantly correlated with nitrogen and sulfur contents in feed and manure (P < 0.05), and with temperature inside the barns (P < 0.05). Calculated emission rates of NH3 ranged from 13.8 to 41.3 g NH3/(AU·d), while calculated emission rates of H2S ranged from 0.15 to 0.46 g H2S/(AU·d). These results will serve as a starting point for a national inventory of NH3 and H2S for the Chinese dairy industry.

Critical issues in the determination of the bentonite cation exchange capacity

The swelling pressure and transport properties of bentonites are controlled by the electric charge density of solid particles, which is commonly estimated from the laboratory measurement of the cation exchange capacity (CEC). However, the standard ammonium displacement method for CEC determination does not take into account the fabric changes that occur in bentonites under exposure to high salt concentration solutions. A series of laboratory tests was conducted to assess the relevance of such a critical issue, by varying the concentration of the extracted potassium chloride (KCl) solution with respect to that of the standard test. The obtained results show that the release of the adsorbed ammonium cations depends on the bentonite fabric, which is controlled by the potassium chloride concentration. As a consequence, the ammonium displacement method may provide an unrepresentative estimate of the CEC of bentonites. The methylene blue titration method, despite its apparently more limited accuracy, instead, seems to provide a more reliable estimation of the CEC, as the bentonite fabric is maintained dispersed during the test.

Hydrogen sulfide-induced relaxation of the bladder is attenuated in spontaneously hypertensive rats.

To compare hydrogen sulfide (H2S)-induced relaxation on the bladder between normotensive and spontaneously hypertensive rat (SHR), we evaluated the effects of H2S donors (GYY4137 and NaHS) on the micturition reflex and on the contractility of bladder tissues. We also investigated the content of H2S and the expression levels of enzymes related to H2S biosynthesis [cystathionine β-synthase (CBS), 3-mercaptopyruvate sulfurtransferase (MPST), and cysteine aminotransferase (CAT)] in the bladder. Eighteen-week-old male normotensive Wistar rats and SHRs were used. Under urethane anesthesia, the effects of intravesically instilled GYY4137 (10-8, 10-7 and 10-6 M) on the micturition reflex were evaluated by cystometry. The effects of NaHS (1 × 10-8-3 × 10-4 M) were evaluated on carbachol (10-5 M)-induced pre-contracted bladder strips. Tissue H2S content was measured by the methylene blue method. The expression levels of these enzymes were investigated by Western blot. GYY4137 significantly prolonged intercontraction intervals in Wistar rats, but not in SHRs. NaHS-induced relaxation on pre-contracted bladder strips was significantly attenuated in SHRs compared with Wistar rats. The H2S content in the bladder of SHRs was significantly higher than that of Wistar rats. CBS, MPST and CAT were detected in the bladder of Wistar rats and SHRs. The expression levels of MPST in the SHR bladder were significantly higher than those in the Wistar rat bladder. H2S-induced bladder relaxation in SHRs is impaired, thereby resulting in a compensatory increase of the H2S content in the SHR bladder.

Cystathionine‑γ‑lyase promotes the metastasis of breast cancer via the VEGF signaling pathway.

The present study aimed to provide data to support the association between cystathionine-γ-lyase (CSE) and breast cancer metastasis. Reverse transcription-quantitative polymerase chain reaction, immunohistochemistry and western blot analysis were used to detect the mRNA and protein expression levels of CSE in human breast cancer tissues and cells. MTS and 5-ethynyl-2′-deoxyuridine assays were used to assess cell viability and proliferation. Scratch wound and Transwell assays were conducted to determine cell migration and invasion. In addition, hydrogen sulfide determination was performed using the methylene blue method. The expression of CSE was upregulated in samples from patients with breast cancer that also exhibit lymph node metastasis, and in grade III and readily metastatic breast cancer cell lines. The proliferation, migration and invasion of breast cancer cells were examined in the present study, and tumor metastasis was observed in nude mice. The function of CSE in breast cancer metastasis depends on the vascular endothelial growth factor (VEGF) signaling pathway, a key mediator of angiogenesis that is crucial for the development and metastasis of tumors. CSE positively regulated the expression of VEGF and increased the levels of certain key proteins in the VEGF pathway, including the phosphoinositide (PI3K)/protein kinase B (AKT) pathway [PI3K, Akt and phosphorylated (p)Akt], focal adhesion kinase (FAK)-paxillin pathway (FAK and paxillin) and rat sarcoma (Ras)-mitogen-activated protein kinase pathway [Ras, rapidly accelerated fibrosarcoma, extracellular signal-regulated kinase (ERK)1/2 and pERK1/2]. Furthermore, the novel CSE inhibitor I157172 possessed antiproliferative and anti-metastatic activities in early MDA-MB-231 metastatic breast cancer cells via inhibition of the VEGF signaling pathway, which further confirmed the role of CSE in breast cancer metastasis. Overall, these data demonstrate for the first time, to the best of our knowledge, that the functions of CSE in breast cancer metastasis are associated with the VEGF signaling pathway.

Application of the Reactive Oxygen-Based Cervical Exfoliated Cell Staining Solution in Clinical Cervical Cancer Screening

We developed a special methylene blue solution for staining of cervix shedding cells based on catalytic oxidizing chromogenic reaction, which shows a potential for cervical cancer cytology screening. We screened a total of 1 922 women for cervical cancer with the special methylene blue staining method and a conventional Pap smear method using cervix shedding cells. Then, the patients with positive indicators of the Pap smear or this special solution staining method were examined by the electron colposcopy and histopathological examination. Staining of cervical exfoliated cells with this reactive oxygen-based special solution showed that the number of positive cases was 140 (7.28%). Among them, 21 cases showed dark green (1.09%), and 119 cases showed purple black (6.19%). The results of the Pap smear method showed that the number of positive cases was 123 (6.40%), of which ASCUS was 105 (5.46%), ASC-H was 5 (0.26%), and LSIL was 9 (0.47%), and HSIL was 4 (0.21%). For cervical exfoliated cell special staining solution for screening cervical intraepithelial neoplasia (CIN-?, CIN-?) and cervical cancer, sensitivity was 83.33%, specificity was 65.52%, accuracy was 74.29%, missed diagnosis rate was 13.33%, positive coincidence rate was 51.43%, and the negative coincidence rate is 86.67%. Our results proved the value of this method for early screening of cervical cancer through clinical practice in China.

Preliminary studies on the anti-osteoporosis activity of Baohuoside I

The aim of the present study was to investigate the anti-osteoporotic activity of Baohuoside I, an active component of Herba Epimedii. Effects of Baohuoside I on the differentiation of BMSCs and the formation of adipocytes were evaluated using alkaline phosphatase staining and methylene blue staining method, respectively. Osteoporosis model was established in ovariectomized rats prior to the measurement of the serum SOD and MDA levels as well as the expression of inflammatory cytokines protein in the rats’ tissues after treatment with Baohuoside I using ELISA assay kits. The estrogen-like effect of Baohuoside I was also measured on HeLa cells. The positive rates of ALP staining in Baohuoside I groups were significantly higher (p < 0.01) compared with the normal group, with no obvious adipocyte formation observed in the groups that received Baohuoside I treatments. The levels of inflammatory markers (IL-1β, TNF-α, IL-6 and IL-8) in the treated groups were significantly lower (p < 0.05) than in the model group. Likewise, the treated groups exhibited a significantly higher (p < 0.05) serum levels of MDA compared with the model group, while SOD levels were markedly lower (p < 0.05) in a dose-dependent fashion. Baohuoside I showed no estrogen-like effect on HeLa cells upon treatment with the drug. Collectively, these results indicated that the anti-osteoporotic activity of Baohuoside I could be related to the induction of BMSCs differentiation into osteoblasts coupled with the inhibition of adipocyte formation, regulation of immune functions, and antioxidant activity.

Evaluation of Nanoporous Carbon Synthesized from Direct Carbonization of a Metal⁻Organic Complex as a Highly Effective Dye Adsorbent and Supercapacitor.

The synthesis of interconnected nanoporous carbon (NPC) material from direct annealing of ultra-small Al-based metal–organic complex (Al-MOC) has been demonstrated. NPC presents a large accessible area of 1054 m2/g, through the Methylene Blue (MB) adsorption method, which is comparable to the high specific surface area (SSA) of 1593 m2/g, through an N2 adsorption/desorption analysis. The adsorption properties and mechanisms were tested by various dye concentrations, pH, and temperature conditions. The high MB accessible area and the good electrical conductivity of the interconnected NPC, led to a large specific capacitance of 205 F/g, with a potential window from 0 to 1.2 V, in a symmetric supercapacitor, and a large energy density of 10.25 Wh/kg, in an aqueous electrolyte, suggesting a large potential in supercapacitors.

Synthesis and Characterization of North Aceh CEC Bentonite Determination with Methylene Blue Method and Increased D-Spacing after Addition of Surfactants CTAB-SDS

Bentonite is not susceptible to polymers because it is organophilic and has low basal spacing. The main objective of this study is to increase bason spacing of bentonite and change the properties of bentonite to hydrophobic by modifying bentonite with cationic and anionic surfactants using Cetyltrimethylammonium bromide (CTAB) and sodium dodecyl sulfate (SDS). Surfactant with different CEC concentration, namely CTAB 1 CEC, 2 CEC and 3 CEC while SDS 0.5 CEC, 1 CEC and 1.5 CEC where the CEC is generated by halometric methods. From the results of the analysis with CEC bentonite value through the halometric method obtained 95.2 meq / 100 grams clay, while the basal spacing of interlayer bentonite with modification of cationic and anionic surfactants using X-Ray Diffraction (XRD) obtained an increase in basal spacing from 14. 18393 Å to 25.08971 Å on CTAB 3 CEC and SDS 1.5 CEC. This research can produce bentonite from northern Aceh with the largest basal spacing so that it can be intercalated by other additives.

Enhanced degradation of indeno(1,2,3-cd)pyrene using Candida tropicalis NN4 in presence of iron nanoparticles and produced biosurfactant: a statistical approach.

Seven yeast isolates were screened for the remediation of indeno(1,2,3-cd)pyrene (InP) using biosynthesized iron nanoparticles and produced biosurfactant in growth medium. Four yeast isolates showed positive response to produce biosurfactant which was confirmed by drop collapse test, emulsification index, methylene blue agar plate method, oil displacement test and lipase activity. The yeast strain showing maximum potential for InP degradation and biosurfactant production was identified as Candida tropicalis NN4. The produced biosurfactant was characterized as sophorolipid type through TLC and FTIR analysis. Iron nanoparticles were biosynthesized using mint leaf extract and characterized by various instrumental analysis. Response surface methodology (RSM), three-level five-variable Box-Behnken design (BBD) was employed to optimize the factors, viz., pH (7), temperature (30°C), salt concentration (1.5gL-1), incubation time (15days) and iron nanoparticles concentration (0.02gL-1) for maximum InP degradation (90.68 ± 0.7%) using C. tropicalis NN4. It was well in close agreement with the predicted value which was obtained by RSM model (90.68 ± 0.4%) indicating the validity of the model. InP degradation was confirmed through FTIR and GC-MS analysis. A kinetic study demonstrated that InP degradation fitted first-order kinetic model. This is the first report on yeast-mediated nanobioremediation of InP and optimization of the whole process using RSM.

Cystathionine β-synthase Induces Multidrug Resistance and Metastasis in Hepatocellular Carcinoma.

This study aims to analyze whether Cystathionine β-synthase (CBS) plays roles in hepatocellular carcinoma (HCC) drug resistance. MTS assay was used to detect the effect of chemotherapeutic drugs doxorubicin (DOX) and sunitinib on HCC cell viability and cell growth. Intracellular doxorubicin accumulation assay was performed to evaluate the sensitivity of DOX and sunitinib in HCC cells and the function of multidrug resistance-associated protein Pglycoprotein (P-gp). Quantification of H2S production was performed using the methylene blue method. Production of intracellular ROS was quantified using the DCFHDA assay. The scratch wound and transwell assays were used to determine the cell migration and invasion. Expression of proteins was tested by western blot analysis. HepG2 cells with high CBS expression were less sensitive to DOX and sunitinib and knockdown of CBS significantly elevated the sensitivity to DOX and sunitinib in HepG2 cells. In contrast, CBS overexpression increased the resistance of DOX and sunitinib in BEL-7404 cells. Moreover, the overexpression of CBS caused the up-regulation of the expression level of P-gp and the decrease of DOX accumulation in BEL-7404 cells. In further mechanism research, we found that STAT3/Akt/Bcl-2 pathway activation, reactive oxygen species (ROS) inhibition as well as enhancement of the metastatic ability of hepatoma cells were responsible for the HCC drug resistance. CBS overexpression conferred HCC cell resistance.

Evaluation of Shale Around Dange, Northwestern Nigeria as Raw Material for Drilling Mud

Shale exposed around Dange northwestern, Nigeria was studied. The aim was to determine the grade, quality and usability of the shale as drilling mud using its physico-chemical and the rheological characteristics.&#x0D; &#x0D; Sixty-one (61) samples were collected from exposed sections and pits. Major elements such as SiO2, Al2O3, MgO and CaO were determined. X-ray diffraction method was employed for the qualitative identification of the minerals in the shale. Cation Exchange Capacity and Exchangeable cations were determined using the Methylene Blue Absorption and Ammonium Acetate Saturation Methods respectively. Grain-size distribution and Atterberg Limits tests were also conducted. Apparent Viscosity, Plastic Viscosity and Yield point were calculated from readings obtained on a multi-speed Fann viscometer.&#x0D; &#x0D; The dominant clay mineral observed is smectite (71%) implying good expansive potential. Dominant oxides were SiO2 (42.60-57.50%), Al2O3 (12.00-16.70%), CaO (0.43-12.50%). Exchangeable cations obtained were Na+ (0.48-6.67), Ca2+ (14.03-34.50) and K+ (0.42-1.95) meq/100g clay. Liquid and plastic limits ranged from 69.40-86.00% and 30.10-36.10% respectively giving a Plasticity Index of 39.40-52.60%.&#x0D; &#x0D; The samples plot close to Ca-montmorillonite on the clay identification chart. The viscosity increased on addition of 7-10% sodium carbonate. It has good sodium exchange potential. In the natural state, it does not meet the API/OCMA specifications. However, its rheological properties improved significantly on treatment with sodium carbonate thus confirming its suitability as raw material in drilling mud.

STUDI ADSORPSI ZAT WARNA NAPHTHOL YELLOW S PADA LIMBAH CAIR MENGGUNAKAN KARBON AKTIF DARI AMPAS TEBU

The aim of this research is to get activated carbon from sugarcane bagasse with high adsorption capacity to Naphthol Yellow S and to know factors influencing the adsorption capacity. Activated carbon is prepared by incomplete combustion of sugracane bagasse. The resulting carbon is activated with H2SO4 with concentration variation of 0.5; 1.0; 1.5 and 2.0 M and is continued by calcination at 400 °C. The measurement of the surface area of ??activated carbon by the methylene blue method indicates that the activation process successfully extends the surface area of carbon from 31.87 m2/g before activation to 66-72 m2/g after activation. Activated carbon with concentration of 2.0 M H2SO4 showed the highest surface area of ??71.85 m2/g, however, the best adsorption was shown by activated carbon with a concentration of 0.5 M H2SO4 with the adsorption capacity of 83.93%. The adsorption test showed that the best amount of adsorbent was 0.2 g with contact time for 30 minutes. Prolonged contact time can decrease the amount of Naphthol Yellow S adsorbed. The best adsorption test result was shown by sample with activator concentration of 0,5 M, mass of 0,2 g and contact time of 30 min with adsorption capacity 95,81% or amount of dye adsorbed equal to 143,72 mg/g. The adsorption study also showed that the entire Naphthol Yellow S adsorption process followed the Langmuir isothemal adsorption model. Qualitative testing of real batik waste indicates that activated carbon can reduce the dyes waste containing Naphthol Yellow Sexhibited by the color of batik waste which is more faded.&#x0D;

Study of Pollution by Anionic Surfactants and Orthophosphates in M’koa Lake (Jacqueville, Côte d’Ivoire)

This study aims to assess the pollution of the surface water from M’koa Lake by both anionic surfactants and orthophosphates, and to identify the sources of pollution by these compounds. Three sampling campaigns were conducted at different seasons at six (6) sampling stations, identified in M'koa Lake by taking into account potential sources of pollution. The measurement of anionic surfactant concentrations was performed by the methylene blue colorimetric method, and the determination of orthophosphates was performed by the vanadomolybdophosphoric acid colorimetric method. In addition, the samples were analyzed in order to find six physico-chemical parameters of surface water quality which are temperature, pH, electrical conductivity, turbidity, oxygen saturation, transparency. The determination of these parameters were made according to both the French AFNOR standard and the methods described by Rodier. The obtained average concentrations of anionic surfactants in the water of M’koa Lake range from 0.23 ± 0.04 mg.L-1 to 1.43 ± 0.68 mg.L-1. Concerning orthophosphates’ content they range from 0.12 ± 0.05 mg.L-1 to 0.17 ± 0.04 mg.L-1. These results indicate that M’koa Lake is subjected to pollution both by anionic surfactants and pollutant enriched by orthophosphate. And, the presence of orthophosphates in lake waters was not due solely to detergents. Washing stations, Berge 1 and 2, and M’koa hotel have the highest levels of anionic surfactants. Also, turbidity and transparency values indicate water quality deterioration of M’koa Lake favoured by the presence of phytoplankton corresponding to the eutrophication of the water of the studied Lake.

Efficiency of ultrasound for degradation of an anionic surfactant from water: Surfactant determination using methylene blue active substances method

The removal of a surfactant from wastewater is usually difficult due to its toxicity and low biodegradability. The aim of this study was to apply sonoreactor for degradation of an anionic surfactant from aqueous solution. An ultrasonic bath with frequency of 130 kHz was used to investigate the effects of different operational parameters such as sonication time, initial concentration and power. In this study, experiments of linear alkylbenzene sulfonates solution were performed using methylene blue active substances method. Experiments were performed at initial concentrations of 0.2 , 0.5 , 0.8 and 1 mg/L, frequency of 130 kHz, acoustic powers value of 400 and 500 W, temperature of 18–20 °C and pH value of 6.8–7. This study showed that linear alkylbenzene sulfonates degradation rate was found to increase with increasing sonication time and power. In addition, as the concentration increased, the linear alkylbenzene sulfonates degradation rate decreased in the ultrasonic reactor.•Surfactants are one of the largest groups of pollutants which exist in almost all urban and many industrial wastewaters.•Ultrasonic reactors alone may not be useful for reducing completely complex wastewaters of high surfactant load.•Application of ultrasonic reactors in combination with other treatment processes including Ozone, UV irradiation, chlorination, Fenton, nanoparticles and H2O2 could be used as a pre-treatment unit in a sequential chemical and biological treatment process.

Validated and Sensitive Spectrophotometric Methods for Estimation of Rizatriptan Benzoate in Pharmaceutical Formulations using Cerium (IV) Sulphate

Three simple, sensitive and accurate spectrophotometric methods have been developed for the determination of rizatriptan benzoate (RZT) in pure form and pharmaceutical formulations. The proposed methods are based on the oxidation of rizatriptan benzoate by a known excess of cerium(IV) sulphate in acid medium followed by determination of unreacted cerium(IV) sulphate by adding a fixed amount of amaranth (AM), methylene blue (MB), and indigo carmine (IC) dyes followed by measuring the absorbance at 518, 663 and 609 nm, respectively. The experimental conditions affecting the reaction were studied and optimized. The beer’s law was obeyed in the concentration ranges of 1.0-10, 0.5-8.0 and 1.0-14 µg mL-1 using AM, MB and IC methods, respectively with a correlation coefficient = 0.9993. The calculated molar absorptivity values are 1.0505 × 104, 1.7331 × 104 and 1.3508 × 104 L mol-1 cm-1 using AM, MB and IC methods, respectively. The limits of detection and quantification are also reported. Intra-day and inter-day precision and accuracy of the methods have been evaluated. The methods were successfully applied to the assay of rizatriptan benzoate in tablets and the results were statistically compared with those of the reference method by applying Student’s t-test and F-test. No interference was observed from the common tablet excipients. The accuracy and reliability of the methods were further ascertained by performing recovery studies using the standard addition method.

Interferents of Automated Reticulocyte Analysis Integrated with Relevant Clinical Cases

Reticulocyte count (RET) has been used for many years to estimate the erythropoietic activity of the bone marrow. Fully automated methods not only provide enhanced precision and accuracy, but also enable reliable measurements of mRNA content and cellular indices. However, problems still exist, such as interference. The aim of the present study was to investigate the interferents of Sysmex XN 9000 reticulocyte analysis and ensure the accuracy of the results. We collected a total of 510 specimens from normal control patients and patients with various diseases including anemias, leukemias, infectious diseases, immune diseases, kidney disease, etc. Correlation of the agreement for reticulocytes between the new methylene blue (NMB) visual microscopy method and automated reticulocyte counting was evaluated by paired sample method according to the CLSI-ICSH document H44-A2-Methods for Reticulocyte Count. Blood smear microscopic examination was carried out on the disturbed samples, and the interferents were analyzed with the medical history, flagging algorithms, the warning information, and the microscopic examination. A total of 44 (8.6%) cases exhibited interference. The main interferents of spuriously high reticulocyte count were caused by parasites, such as malaria, as well as suspicious autofluorescence due to drugs, while the main interferents of spuriously low reticulocyte count were caused by RBC fragments. Detection of potential interferences may be accomplished through alarm information and flagging algorithms incorporated into the instrument and by examination of a blood film to ensure absence of relevant interferences.