Role of reactive manganese and oxygen species in the KMnO4/Na2SO3 process for purification of algal-rich water and membrane fouling alleviation.

Ultrafiltration (UF) is a highly efficient technique for algal-rich water purification, but it is heavily contaminated due to the complex water characteristics. To solve this problem, potassium permanganate (KMnO4) oxidation enhanced with sodium sulfite (Na2SO3) was proposed as a pretreatment means. The results showed that the end-normalized flux was elevated from 0.10 to 0.91, and the reversible fouling resistance was reduced by 99.95%. The membrane fouling mechanism also changed obviously, without the generation of cake filtration. Regarding the properties of algal-rich water, the zeta potential was decreased from -29.50 to -5.87 mV after KMnO4/Na2SO3 pretreatment, suggesting that the electrostatic repulsion was significantly reduced. Meanwhile, the fluorescent components in algal-rich water were significantly eliminated, and the removal of dissolved organic carbon was increased to 67.46%. In the KMnO4/Na2SO3 process, reactive manganese species (i.e., Mn(V), Mn(III) and MnO2) and reactive oxygen species (i.e., SO4•- and •OH) played major roles in purifying algal-rich water. Specifically, SO4•-, •OH, Mn(V) and Mn(III) could effectively oxidize algal pollutants. Simultaneously, the in-situ adsorption and coagulation of MnO2 could accelerate the formation of flocs by decreasing the electrostatic repulsion between cells, and protect the algal cells from being excessive oxidized. Overall, the KMnO4/Na2SO3 process showed significant potential for membrane fouling alleviation in purifying algal-rich water.

Experimental evidence of effective disinfectant to control the transmission of Micropterus salmoides rhabdovirus.

Micropterus salmoides rhabdovirus (MSRV) is a significant pathogen that causes high morbidity and mortality in largemouth bass, leading to enormous economic losses for largemouth bass aquaculture in China. The aim of this study was to investigate the efficacy of four disinfectants (potassium permanganate, glutaraldehyde, trichloroisocyanuric acid and povidone iodine) on MSRV, to control the infection and transmission of MSRV in largemouth bass aquaculture. The disinfectants were tested at different concentrations (5, 25, 50, 100 and 500 mg/L) prepared with distilled water for 30 min contact time, and the viral nucleic acid was quantified using qPCR and the infectivity was tested by challenge experiment. Potassium permanganate at 5-500 mg/L, glutaraldehyde at 500 mg/L, trichloroisocyanuric acid at 50-500 mg/L and povidone iodine at 500 mg/L concentration could effectively decrease the virus nucleic acid, and the survival rate of largemouth bass juveniles after challenge experiment increased significantly from 3.7% ± 6.41% to 33.33 ± 11.11% - 100%. Moreover, the minimum effective time of 5 mg/L potassium permanganate was further studied at 2, 5, 10 and 20 min contact time. The viral nucleic acid decreased significantly at 5-20 min exposure time, and the survival rate increased significantly from 7.41% ± 6.41% to 77.78 ± 11.11% - 100%. The median lethal concentration (LC50 ) values of potassium permanganate were 10.64, 6.92 and 3.7 mg/L at 24, 48 and 96 h, respectively. Potassium permanganate could be used for the control of MSRV in the cultivation process; the recommended concentration is 5 mg/L and application time should be less than 24 h. The results could be applied to provide a method to control the infection and transmission of MSRV in water, and improve the health status of largemouth bass.

Investigating the impact of external application of formalin and potassium permanganate on hematological, immunological, and biochemical profiles in Labeo rohita fingerlings.

The present study aimed to elucidate the suitability of formalin and KMnO4 as therapeutics for fish diseases in Indian major carp, Labeo rohita, while considering their impact on fish stress levels. Acute toxicity tests revealed that the 96-hour LC50 values for formalin and KMnO4 were 66.58 ppm and 2.89 ppm, respectively. Sub-lethal concentrations of formalin (6.65 ppm, 3.32 ppm, and 2.21 ppm) and KMnO4 (0.289 ppm, 0.145 ppm, and 0.096 ppm), along with control groups, were administered to the fish for different exposure periods (24, 48, 72, and 96 hours) and different hematological, biochemical, and immunological parameters were analyzed. The findings demonstrated that formalin exposure resulted in a significant decrease (p < 0.05) in hematological parameters, immunological parameters, and serum protein levels. Conversely, formalin exposure led to significant increases (p < 0.05) in serum glucose, SGOT, SGPT, and ALP levels. In contrast, KMnO4 exposure significantly decreased (p < 0.05) hematological parameters and serum protein levels, while significantly increasing (p < 0.05) immunological parameters. To evaluate curative efficacy, challenge studies were conducted using three sub-lethal concentrations of formalin and KMnO4 against Aeromonas hydrophila (ATCC 7966) infection. Based on the aforementioned results, the recommended doses of formalin and KMnO4 were found to be 6.65 ppm and 0.289 ppm, respectively.

Remediation of cadmium contaminated soil using K2FeO4 modified vinasse biochar.

The remediation of cadmium (Cd) contaminated soil is challenging for agricultural practices. In this study, a novel vinasse biochar modified by potassium ferrate (K2FeO4) was synthesized to immobilize Cd in agricultural soil. Three biochars [i.e., vinasse biochar (BC), KMnO4 modified vinasse biochar (MnBC), and K2FeO4 modified vinasse biochar (FeBC)] were applied to compare their efficiencies of Cd immobilization. The results showed that the orders of pH, ash content, and functional groups in different biochar were the same following BC < MnBC < FeBC. Scanning electron microscope images showed that the FeBC has more micropores than MnBC and BC. X-ray diffraction identified manganese oxides and iron oxides within MnBC and FeBC, indicating that Mn and Fe were well loaded on the biochar. In the soil-based pot experiment, both MnBC and FeBC significantly reduced soil available Cd by 23-38% and 36-45% compared with the control, respectively (p < 0.05). In addition, the application of BC, MnBC, and FeBC significantly increased the yield, chlorophyll, and vitamin C of Chinese cabbage (p < 0.05), and decreased its Cd uptake compared with the control. Notably, shoot Cd significantly reduced when 2% FeBC was applied (p < 0.05). Overall, using K2FeO4 to modify vinasse biochar enriched the surface functional groups and minerals as well as reduced Cd availability in soil and its uptake by the plant. Our study showed that K2FeO4 modified vinasse biochar could be used as an ideal amendment for the remediation of Cd-contaminated soil.

Flow injection chemiluminescence determination of acetochlor and cartap-HCl in freshwater samples using an acidic KMnO4 -rhodamine-B reaction system.

A flow injection (FI) methodology using the acidic potassium permanganate (KMnO4 )-rhodamine-B (Rh-B) reaction with chemiluminescence (CL) detection was established to determine acetochlor and cartap-HCl pesticides in freshwater samples. Experimental parameters were optimized, and Chelex-100 cationic exchanger mini column and solid-phase extraction (SPE) were used as phase separation techniques. Linear calibration curves were observed for the standard solutions of acetochlor and cartap-HCl over the ranges 0.005-2.0 mg L-1 [y = 1155.8x + 57.551, R2  = 0.9999 (n = 8)] and 0.005-1.0 mg L-1 [y = 979.76x + 14.491, R2  = 0.9998 (n = 8)] with LODs and LOQs of 7.5 × 10-4 and 8.0 × 10-4  mg L-1 (3σ blank) and 2.5 × 10-3 and 2.7 × 10-3  mg L-1 (10σ blank), respectively, with an injection throughput of 140 h-1 . These methods were used to estimate acetochlor and cartap-HCl with or without the SPE procedure, respectively, in spiked freshwater samples. Results obtained were not significantly different at a 95% confidence level to those of other reported methods. Recoveries for acetochlor and cartap-HCl were obtained over the ranges 93-112% (RSD = 1.9-3.6%) and 98-109% (RSD = 1.7-3.8%), respectively. The most probable CL reaction mechanism was explored.

Potassium permanganate is an excellent alternative to osmium tetroxide in freeze-substitution.

High-pressure freezing followed by freeze-substitution is a valuable method for ultrastructural analyses of resin-embedded biological samples. The visualization of lipid membranes is one of the most critical aspects of any ultrastructural study and can be especially challenging in high-pressure frozen specimens. Historically, osmium tetroxide has been the preferred fixative and staining agent for lipid-containing structures in freeze-substitution solutions. However, osmium tetroxide is not only a rare and expensive material, but also volatile and toxic. Here, we introduce the use of a combination of potassium permanganate, uranyl acetate, and water in acetone as complementing reagents during the freeze-substitution process. This mix imparts an intense en bloc stain to cellular ultrastructure and membranes, which makes poststaining superfluous and is well suited for block-face imaging. Thus, potassium permanganate can effectively replace osmium tetroxide in the freeze-substitution solution without sacrificing the quality of ultrastructural preservation.

Caustic ingestion in children treated at a tertiary centre in South Africa: can upper endoscopy be omitted in asymptomatic patients?

PURPOSE: Considering that clinical presentation and gastrointestinal tract (GIT) injuries post-caustic ingestion vary in children, this study aims to establish whether a correlation exists between clinical presentation and endoscopic findings. METHODS: This retrospective study comprised patients referred to a paediatric surgical unit between 2016 and 2018 within 72 h post-caustic ingestion. Data collected included caustic agents ingested, clinical presentation, endoscopic findings and management. Oesophageal injuries were graded according to the Zargar's endoscopic classification and gastric injuries classified as mild to severe. RESULTS: Fifty patients with a mean age of 2.4 years were managed during the study period. Potassium permanganate (KMNO4) was the most frequently ingested substance in 27 (54%) patients. All 30 (60%) asymptomatic patients had no positive endoscopic findings regardless of clinical signs. Among the symptomatic patients (n = 20), 15 (75%) had oesophageal injuries (p = 0.01). Stridor was associated with a higher grade of oesophageal injury (p = 0.007). CONCLUSIONS: Clinical signs and symptoms post-caustic ingestion correlated with endoscopic findings in our study. Endoscopy can be safely omitted in asymptomatic patients, including those with isolated staining secondary to KMNO4 ingestion. Symptomatic patients should have an endoscopy performed within 48-72 h of the insult to diagnose injuries.

Green synthesis of multipurpose carbon quantum dots from red cabbage and estimation of their antioxidant potential and bio-labeling activity.

We present a green synthesis of fluorescent carbon quantum dots (CQDs) by using red cabbage (rc) and a one-step hydrothermal approach. The rcCQDs were characterized by various techniques such as UV-visible spectroscopy, transmission electron microscopy (TEM), high-resolution TEM, Fourier-transform infrared spectroscopy, atomic force microscopy (AFM), and X-ray photoelectron spectroscopy. The synthesized rcCQDs exhibited an average size of 3 nm, measured by TEM, blue fluorescence, and a quantum yield of 8.3%. The highest emission band was observed at approximately 402 nm when excited at 330 nm. The rcCQDs exhibited strong antioxidant activities by scavenging 61, 56, and 91% against 2, 2-diphenyl-1-picrylhydrazyl, hydroxyl, and potassium permanganate radicals, respectively. The scavenging activity of rcCQDs was comparable with that of standard antioxidant L-ascorbic acid. Cell Counting Kit (CCK)-8 assay depicted superior bio-compatibility and negligible cytotoxicity of rcCQDs on SH-SY5Y neuroblastoma cells. They were used as a fluorescent probe for bio-labeling of Escherichia coli and Staphylococcus aureus. The viabilities of the labeled bacterial cells were analyzed by AFM and UV-visible spectroscopy. Furthermore, the rcCQDs were utilized as a fluorescent ink, an alternative to pens, and maybe suitable for paints and varnish agents. This study provides detailed mechanistic insights into the antioxidant activity of as-synthesized rcCQDs, which suggest the practical applicability of CQDs for bio-medical applications. Key points • Carbon quantum dots were prepared from red cabbage using the hydrothermal method. • The scavenging activity of rcCQDs was evaluated for DPPH, OH, and KMnO4radicals. • The rcCQDs were used for the labeling of foodborne bacteria. • The rcCQDs could be utilized as fluorescent ink. Graphical abstract Schematic representation of CQDs prepared from red cabbage (rc) with multifunctional applications.

Toxic heavy metal removal from sulfide ores using potassium permanganate: Process development and waste management.

A monolithic new attitude utilizing Aspen Plus software and Taguchi method has been applied to evaluate a novel configuration for removal of toxic heavy metals during sulfide ores recovery using potassium permanganate (KMnO4). In this new configuration, KMnO4 has been produced by sludge recovery of cobalt purification step containing manganese (IV) oxide (MnO2). Also, in this suggested configuration, the required sulfuric acid (H2SO4) solvent has been provided by recovery of sulfur compounds released during leaching process of sulfide ores. The optimum condition obtained by Taguchi experimental design has been used as initial data for the simulation and sensitivity analysis of process via Aspen Plus software. A systematic study of the design and operating condition has been made for key performance metrics such as removal of toxic heavy metal from sulfide ores, recovery of KMnO4 from sludge containing MnO2 and conversion of released sulfide gases to H2SO4 at the different operating condition such as H2SO4 concentration of 60-90 g/L, operating temperature of 60-150 °C, agitation rate of 100-400 rpm, reaction time of 0.5-2 h, solid to liquid ratio of 1:1-1:4, particle size of 10-500 µm, additive amount of 10-40 wt% and oxygen pressure of 0.5-2 MPa. The optimum condition for removal of toxic heavy metal have been found to be H2SO4 concentration of 70 g/L, temperature of 90 °C, agitation rate of 200 rpm, reaction time of 1.5 h, particle size of 500 µm, solid to liquid ratio of 1:2, additive amount of 40 wt% and oxygen pressure of 1.5 MPa. According to simulation results, the maximum conversion of released sulfide gases to H2SO4, recovery of KMnO4 and toxic heavy metals removal during designed process at optimized condition are 98%, 91% and 99%, respectively.

The effect of fucoidan or potassium permanganate on growth performance, intestinal pathology, and antioxidant status in Nile tilapia (Oreochromis niloticus).

Fucoidans are marine algal sulfated glycans that are widely used as dietary additives in aquaculture. These glycans are recognized as beneficial supplements for their antimicrobial, anti-inflammatory, anticancer, and antiviral properties. Potassium permanganate is another commonly used chemical that is used in aquaculture to treat infections in fish. Despite their widespread use, there are few data available regarding the potential sublethal toxicity associated with fucoidan and potassium permanganate treatments of fish. In this study, we investigated the effect of each compound on the growth, intestinal health, and antioxidant status of Nile tilapia (Oreochromis niloticus). Both compounds affected the growth of experimental fish compared with untreated fish. However, while growth parameters were positively associated with the dose of fucoidan administered, growth was negatively associated with the dose of potassium permanganate in Nile tilapia. Fucoidan treatment was observed to improve the intestinal health of fish based upon increases in intestinal villous area, intestinal villous length and width, and the intraepithelial lymphocyte number and decreases in the total intestinal bacterial count compared with untreated fish. Conversely, potassium permanganate induced intestinal epithelium proliferation and villous branching, a histopathological response typically observed with chemical irritants. Both fucoidan and potassium permanganate decreased levels of oxidative and nitrosative stress markers and enhanced the antioxidant status in multiple organs. Taken together, fucoidan dietary application improved the growth, intestinal health, and antioxidant status in Nile tilapia, supporting the use of this compound as a promising feed additive for aquaculture production. Conversely, potassium permanganate baths have negative effects on fish growth at higher doses and appeared to act as a gastrointestinal irritant in tilapia. This study improves knowledge regarding the biochemical and histological responses in Nile tilapia to two widely used aquaculture-related treatments.

Degradation of petroleum hydrocarbons in unsaturated soil and effects on subsequent biodegradation by potassium permanganate.

To date, the oxidation of petroleum hydrocarbons using permanganate has been investigated rarely. Only a few studies on the remediation of unsaturated soil using permanganate can be found in the literature. This is, to the best of our knowledge, the first study conducted using permanganate pretreatment to degrade petroleum hydrocarbons in unsaturated soil in combination with subsequent bioaugmentation. The pretreatment of diesel-contaminated unsaturated soil with 0.5-pore-volume (5%) potassium permanganate (PP) by solution pouring and foam spraying (with a surfactant) achieved the total petroleum hydrocarbon (TPH) removal efficiencies of 37% and 72.1%, respectively. The PP foam, when coupled with bioaugmentation foam, further degraded the TPH to a final concentration of 438 mg/kg (92.1% total reduction). The experiment was conducted without soil mixing or disturbance. The relatively high TPH removal efficiency achieved by the PP-bioaugmentation serial foam application may be attributed to an increase in soil pH caused by the PP and effective infiltration of the remediation agent by foaming. The applied PP foam increased the pH of the acidic soil, thus enhancing microbial activity. The first-order biodegradation rate after PP oxidation was calculated to be 0.068 d-1. Furthermore, 94% of the group of relatively persistent hydrocarbons (C18-C22) was removed by PP-bioaugmentation, as verified by chromatogram peaks. Some physicochemical parameters related to contaminant removal efficiency were also evaluated. The results reveal that PP can degrade soil TPH and significantly enhance the biodegradation rate in unsaturated diesel-contaminated soil when combined with bioaugmentation foam.

Fluorometric determination of antioxidant capacity in human plasma by using upconversion nanoparticles and an inner filter effect mechanism.

The balance between free oxygen radicals and antioxidant defense systems is usually assessed by an antioxidant capacity assay. A rapid and sensitive antioxidant capacity assay is described here. It is making use of NaYF4:Yb/Er@NaYF4 core-shell upconversion nanoparticles (UCNPs) and potassium permanganate (KMnO4). In this strategy, added KMnO4 reduces the green (540 nm) emission of the UCNPs (under 980 nm photoexcitation) due to an inner filter effect. The antioxidants cysteine, ascorbic acid and glutathione (GSH) reduce the intense purple color of KMnO4 because it is reduced to Mn(II) ion. Hence, the green upconversion fluorescence is restored after the addition of antioxidants. Figures of merit for this assay (for the case of GSH) include a detection limit of 3.3 µM, a detection range that extends from 10 µM to 2.5 mM, and an assay time of a few seconds. The assay was applied to the evaluation of antioxidant capacity in human plasma samples spiked with GSH and gave satisfactory repeatability and specificity. Graphical abstract Schematic presentation of a fluorometric assay based on inner filter effect (IFE) between upconversion nanoparticles (UCNPs) and potassium permanganate (KMnO4) for the determination of antioxidant capacity in human plasma.

Experimental investigation and mathematical modeling for microbial removal using potassium permanganate as an oxidant-case study: water treatment plant No. 1, Mashhad, Iran.

Preoxidation is an important unit process which can partially remove organic and microbial contaminations. Due to the high concentrations of organic matter entering the water treatment plant, originating from surface water resources, preoxidation by using chlorinated compounds may increase the possibility of trihalomethane (THM) formation. Therefore, in order to reduce the concentration of THMs, different alternatives such as injection of potassium permanganate are utilized. The present study attempts to investigate the efficiency of the microbial removal from raw water entering the water treatment plant No. 1 in Mashhad, Iran, through various doses of potassium permanganate. Then, an examination of the predictive models is done in order to indicate the residual Escherichia coli and total coliform resulted from injecting the potassium permanganate. Finally, the coefficients of the proposed models were optimized using the genetic algorithm. The results of the study show that 0.5 mg L-1 of potassium permanganate would remove 50% of total coliform as well as 80% of Escherichia coli in the studied water treatment plant. Also, assessing the performance of different models in predicting the residual microbial concentration after injection of potassium permanganate suggests the Gaussian model as the one resulting the highest conformity. Moreover, it can be concluded that employing smart models leads to an optimization of the injected potassium permanganate at the levels of 27% and 73.5%, for minimum and maximum states during different seasons of a year, respectively.

Enhancing the chemiluminescence intensity of a KMnO4 formaldehyde system for estimating the total phenolic content in honey samples using a novel nanodroplet mixing approach in a microfluidics platform.

A novel mixing approach was utilized with a highly sensitive chemiluminescence (CL) method to determine the total phenolic content (TPC) in honey samples using an acidic potassium permanganate-formaldehyde system. The mixing approach was based on exploiting the mixing efficiency of nanodroplets generated in a microfluidic platform. Careful optimization of the instrument setup and various experimental conditions were employed to obtain excellent sensitivity. The mixing efficiency of the droplets was compared with the CL signal intensity obtained using the common serpentine chip design, with both approaches using at a total flow rate of 15 µl min-1 ; the results showed that the nanodroplets provided 600% higher CL signal intensity at this low flow rate. Using the optimum conditions, calibration equations, limits of detection (LOD) and limits of quantification (LOQ) for gallic acid (GA), caffeic acid (CA), kaempferol (KAM), quercetin (QRC) and catechin (CAT) were obtained. The LOD ranged from 6.2 ppb for CA to 11.0 ppb for QRC. Finally, the method was applied for the determination of TPC in several local and commercial honey samples.

Microwave-assisted surface modification for the separation of polycarbonate from polymethylmethacrylate and polyvinyl chloride waste plastics by flotation.

Microwave-assisted potassium permanganate modification (MPPM) was used for the flotation separation of polycarbonate (PC) from polyvinyl chloride (PVC) and polymethylmethacrylate (PMMA) waste plastics. The separation process was optimized by investigating the potassium permanganate concentration, treatment time, flotation time and frother concentration. MPPM selectively reduced the flotation recovery of PC. The optimum conditions were determined to be: potassium permanganate concentration, 2 mM/L; treatment time, 1 min; frother concentration, 17.57 g/L; and flotation time, 1 min. PC was efficiently separated from PVC and PMMA under the optimum conditions. The purity of the separated PC was 97.71%. The purity and recovery of PVC and PMMA were both >95%. The modification mechanism was investigated using the water contact angles, Fourier transform infrared spectrometry and scanning electron microscopy. This work provides technical insights into the industrial recycling of waste plastics.

Drinking water treatment using a submerged internal-circulation membrane coagulation reactor coupled with permanganate oxidation.

A submerged internal circulating membrane coagulation reactor (MCR) was used to treat surface water to produce drinking water. Polyaluminum chloride (PACl) was used as coagulant, and a hydrophilic polyvinylidene fluoride (PVDF) submerged hollow fiber microfiltration membrane was employed. The influences of trans-membrane pressure (TMP), zeta potential (ZP) of the suspended particles in raw water, and KMnO4 dosing on water flux and the removal of turbidity and organic matter were systematically investigated. Continuous bench-scale experiments showed that the permeate quality of the MCR satisfied the requirement for a centralized water supply, according to the Standards for Drinking Water Quality of China (GB 5749-2006), as evaluated by turbidity (<1 NTU) and total organic carbon (TOC) (<5mg/L) measurements. Besides water flux, the removal of turbidity, TOC and dissolved organic carbon (DOC) in the raw water also increased with increasing TMP in the range of 0.01-0.05MPa. High ZP induced by PACl, such as 5-9mV, led to an increase in the number of fine and total particles in the MCR, and consequently caused serious membrane fouling and high permeate turbidity. However, the removal of TOC and DOC increased with increasing ZP. A slightly positive ZP, such as 1-2mV, corresponding to charge neutralization coagulation, was favorable for membrane fouling control. Moreover, dosing with KMnO4 could further improve the removal of turbidity and DOC, thereby mitigating membrane fouling. The results are helpful for the application of the MCR in producing drinking water and also beneficial to the research and application of other coagulation and membrane separation hybrid processes.

The discovery and early structural studies of arachidonic acid.

Arachidonic acid and esterified arachidonate are ubiquitous components of every mammalian cell. This polyunsaturated fatty acid serves very important biochemical roles, including being the direct precursor of bioactive lipid mediators such as prostaglandin and leukotrienes. This 20 carbon fatty acid with four double bonds was first isolated and identified from mammalian tissues in 1909 by Percival Hartley. This was accomplished prior to the advent of chromatography or any spectroscopic methodology (MS, infrared, UV, or NMR). The name, arachidonic, was suggested in 1913 based on its relationship to the well-known arachidic acid (C20:0). It took until 1940 before the positions of the four double bonds were defined at 5,8,11,14 of the 20-carbon chain. Total synthesis was reported in 1961 and, finally, the configuration of the double bonds was confirmed as all-cis-5,8,11,14. By the 1930s, the relationship of arachidonic acid within the family of essential fatty acids helped cue an understanding of its structure and the biosynthetic pathway. Herein, we review the findings leading up to the discovery of arachidonic acid and the progress toward its complete structural elucidation.

Managing Ammonia Emissions From Screwworm Larval Rearing Media.

Mass production, sterilization, and release of screwworms (Cochliomyia hominivorax (Coquerel)) that were competitive in the field significantly contributed to the successful application of the sterile insect technique for eradication of screwworms from continental North America. Metabolic byproducts resulting from protein-rich diets required for larval screwworms lead to ammonia liberation, sometimes at high levels, within the mass rearing facility. Until recently a sodium polyacrylate gel bulking agent was used for the larval media and adsorbed much of the ammonia. A need to replace the gel with an environmentally "friendly" bulking agent, while not increasing ammonia levels in the rearing facility, led to a series of experiments with the objective of developing procedures to reduce ammonia emissions from the larval media bulked with cellulose fiber. Additives of ammonia-converting bacteria, potassium permanganate, and Yucca schidigera Roezl ex Otrgies powder extract, previously reported to reduce ammonia levels in organic environments, were evaluated. Ammonia-converting bacteria did not have a positive effect. Addition of Y. schidigera powder extract (∼1% of total volume), potassium permanganate (∼250 ppm), and a combination of these two additives (at these same concentrations) kept ammonia at equivalent levels as when larval media was bulked with gel. Potassium permanganate also had sufficient antimicrobial properties that the use of formaldehyde in the diet was not necessary. Further testing is needed, at a mass rearing level, before full implementation into the screwworm eradication program.

A novel system of galangin-potassium permanganate-polyphosphoric acid for the determination of tryptophan and its chemiluminescence mechanism.

A novel galangin-potassium permanganate (KMnO4)-polyphosphoric acid (PPA) system was found to have an outstanding response to tryptophan (Trp). Trp determination using this KMnO4 -PPA system was enhanced significantly in the presence of galangin. A highly sensitive flow-injection chemiluminescence (CL) method to determine Trp was developed based on the CL reaction of galangin-KMnO4 -Trp in PPA media. The presence of galangin, a member of the flavonol class of flavonoid complexes, greatly increased the luminous intensity of Trp in KMnO4 -PPA systems. Under optimized conditions, Trp was determined in the 0.05-10 µg/mL range, with a detection limit (3σ) of 5.0 × 10(-3) µg/mL. The relative standard deviation (RSD) was 1.0% for 11 replicate determinations of 1.0 µg/mL Trp. Two synthetic samples were determined selectively with recoveries of 98.4-100.1% in the presence of other amino acids. The possible mechanism is summarized as follows: excited states of Mn(II)(*) and Mn(III(*) types are the main means of generating chemical luminescent species, and Trp concentration and luminescence intensity have a linear relationship, which enables quantitative analysis.

Determination of ethanol using permanganate-CdS quantum dot chemiluminescence system.

A novel and highly sensitive chemiluminescence (CL) method for the determination of ethanol was developed based on the CdS quantum dots (QDs)-permanganate system. It was found that KMnO4 could directly oxidize CdS QDs in acidic media resulting in relatively high CL emission. A possible mechanism was proposed for this reaction based on UV/Vis absorption, fluorescence and the generated CL emission spectra. However, it was observed that ethanol had a remarkable inhibition effect on this system. This effect was exploited in the determination of ethanol within the concentration range 12-300 µg/L, with detection at 4.3 µg/L. In order to evaluate the capability of presented method, it was satisfactorily utilized in the determination of alcohol in real samples.