A very simple, ultra-sensitive, highly selective and non-extractive new spectrofluorimetric method for the determination of arsenic at pico-trace levels using 2-(α-pyridyl)-thioquinaldinamide (PTQA) has been develope...A very simple, ultra-sensitive, highly selective and non-extractive new spectrofluorimetric method for the determination of arsenic at pico-trace levels using 2-(α-pyridyl)-thioquinaldinamide (PTQA) has been developed. PTQA has been proposed as a new analytical reagent for the direct non-extractive spectrofluorimetric determination of Arsenic (V). This novel fluorimetric reagent, PTQA becomes oxidized in a slightly acidic (0.025 - 0.1 M H2SO4) solution with Arsenic (V) in absolute ethanol to produce highly fluorescent oxidized product (λex = 303 nm;λem = 365 nm). Constant and maximum fluorescence intensities were observed over a wide range of acidity (0.025 - 0.1 M H2SO4) for the period between 2 min and 24 h. Linear calibration graphs were obtained for 0.001 - 800-μgL-1 of As, having a detection limit of 0.1-ngL-1;the quantification limit of the reaction system was found to be 1-ngL-1 and the RSD was 0% - 2%. A large excess of over 60 cations, anions and complexion agents (like, chloride, phosphate, azide, tartrate, oxalate, SCN, etc.) do not interfere in the determination. The developed method was successfully used in the determination of arsenic in several Certified Reference Materials (alloys, steels, ores, human urine, hair, nails, bovine liver and sediments) as well as in some biological fluids (human blood, urine, hair, nail and milk), soil samples, food samples (vegetables, fruits, rice, corn and wheat), solutions containing both arsenic (III) and arsenic (V) speciation and complex synthetic mixtures. The results of the proposed method for assessing biological, food and soil samples were comparable with both ICP-OES & AHG-AAS and were found to be in excellent agreement.展开更多
The conversion study on the environmental quality criteria between water/air and soil is the need to carry out research on soil-environmental quality standards in an all-round way, and also the demand for solving emer...The conversion study on the environmental quality criteria between water/air and soil is the need to carry out research on soil-environmental quality standards in an all-round way, and also the demand for solving emerging problems in this field using the system dynamic and the overall view. Carrying out this study is of practical significance and theoretical values in the face of formulation and revision of soil-environmental quality standards in China. Firstly, the theoretical basis and relative models of soil-water and soil-air systems were expounded, respectively. And on this basis, a preliminary conceptual model about the conversion was constructed. After that, the current worldwide environmental quality criteria/standards for soil, water and air media were introduced based on their types, concerned pollutants and hierarchical classification, and their variation were also analyzed briefly. Particularlly, the key points for the conversion of environmental quality criteria between soil and water and/or between soil and air were discussed, respectively, while combined with the relative researching results. Finally, this conversion study was commented and prospected.展开更多
文摘A very simple, ultra-sensitive, highly selective and non-extractive new spectrofluorimetric method for the determination of arsenic at pico-trace levels using 2-(α-pyridyl)-thioquinaldinamide (PTQA) has been developed. PTQA has been proposed as a new analytical reagent for the direct non-extractive spectrofluorimetric determination of Arsenic (V). This novel fluorimetric reagent, PTQA becomes oxidized in a slightly acidic (0.025 - 0.1 M H2SO4) solution with Arsenic (V) in absolute ethanol to produce highly fluorescent oxidized product (λex = 303 nm;λem = 365 nm). Constant and maximum fluorescence intensities were observed over a wide range of acidity (0.025 - 0.1 M H2SO4) for the period between 2 min and 24 h. Linear calibration graphs were obtained for 0.001 - 800-μgL-1 of As, having a detection limit of 0.1-ngL-1;the quantification limit of the reaction system was found to be 1-ngL-1 and the RSD was 0% - 2%. A large excess of over 60 cations, anions and complexion agents (like, chloride, phosphate, azide, tartrate, oxalate, SCN, etc.) do not interfere in the determination. The developed method was successfully used in the determination of arsenic in several Certified Reference Materials (alloys, steels, ores, human urine, hair, nails, bovine liver and sediments) as well as in some biological fluids (human blood, urine, hair, nail and milk), soil samples, food samples (vegetables, fruits, rice, corn and wheat), solutions containing both arsenic (III) and arsenic (V) speciation and complex synthetic mixtures. The results of the proposed method for assessing biological, food and soil samples were comparable with both ICP-OES & AHG-AAS and were found to be in excellent agreement.
基金financially supported by the Ministry of Education, People’s Republic of China as a program for the Introducing Talents of Discipline to Universities (Grant No. T2017002)Special Funds for Basic Scientific Research Services of Central Colleges and Universities
文摘The conversion study on the environmental quality criteria between water/air and soil is the need to carry out research on soil-environmental quality standards in an all-round way, and also the demand for solving emerging problems in this field using the system dynamic and the overall view. Carrying out this study is of practical significance and theoretical values in the face of formulation and revision of soil-environmental quality standards in China. Firstly, the theoretical basis and relative models of soil-water and soil-air systems were expounded, respectively. And on this basis, a preliminary conceptual model about the conversion was constructed. After that, the current worldwide environmental quality criteria/standards for soil, water and air media were introduced based on their types, concerned pollutants and hierarchical classification, and their variation were also analyzed briefly. Particularlly, the key points for the conversion of environmental quality criteria between soil and water and/or between soil and air were discussed, respectively, while combined with the relative researching results. Finally, this conversion study was commented and prospected.
