Advances in sample digestion using microwave-ultraviolet radiations: phosphorus and sulfur determination in animal feed

2020 ◽  
Vol 16 ◽  
Author(s):  
Diogo L. R. Novo ◽  
Priscila T. Scaglioni ◽  
Rodrigo M. Pereira ◽  
Filipe S. Rondan ◽  
Gilberto S. Coelho Junior ◽  
...  

Background: Conventional analytical methods for phosphorus and sulfur determination in several matrices present normally analytical challenges regarding inaccuracy, detectability and waste generation. Objective: The main objective is proposing a green and feasible analytical method for phosphorus and sulfur determination in animal feed. Methods: Synergic effect between microwave and ultraviolet radiations during sample preparation was evaluated for the first time for the animal feed digestion associated with further phosphorus and sulfur determination by ion chromatography with conductivity detection. Dissolved carbon and residual acidity in final digests were used for the proposed method assessment. Phosphorus and sulfur values were compared with those obtained using conventional microwave-assisted wet digestion in closed vessels associated with inductively coupled plasma optical emission spectrometry and with those obtained using Association of Official Analytical Chemists International official method. Recovery tests and certified reference material analysis were performed. Animal feeds were analyzed using the proposed method. Results: Sample masses of 500 mg were efficiently digested using only 2 mol L -1 HNO3. The results obtained by the proposed method was not differing significantly (p > 0.05) from those obtained by the conventional and official methods. Suitable recoveries (from 94 to 99%), agreement with certified values (101 and 104%) and relative standard deviations (< 8%) were achieved. Phosphorus and sulfur content in commercial products varied in a wide range (P: 5,873 to 28,387 mg kg-1 and S: 2,165 to 4,501 mg kg-1 ). Conclusion: The proposed method is a green, safe, accurate, precise and sensitive alternative for animal feed quality control.

Diagnostics ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1066
Author(s):  
Midori Nagai ◽  
Koichi Sakurada ◽  
Kazuhiko Imaizumi ◽  
Yoshinori Ogawa ◽  
Motohiro Uo ◽  
...  

The postmortem interval (PMI) of victims is a key parameter in criminal investigations. However, effective methods for estimating the PMI of skeletal remains have not been established because it is determined by various factors, including environmental conditions. To identify effective parameters for estimating the PMI of skeletal remains, we investigated the change in bone focusing on the amount of DNA, element concentrations, and bone density that occurred in the bone samples of bovine femurs, each maintained under one of five simulated environmental conditions (seawater, freshwater, underground, outdoors, and indoors) for 1 year. The amount of extracted mitochondrial DNA (mtDNA; 404 bp fragment) decreased over time, and significant DNA degradation (p < 0.01), as estimated by a comparison with amplification results for a shorter fragment (128 bp), was detected between 1 month and 3 months. Eleven of 30 elements were detected in samples by inductively coupled plasma optical emission spectrometry, and Na and Ba showed significant quantitative differences in terms of environmental conditions and time (p < 0.01). This preliminary study suggests that the level of DNA degradation determined by real-time polymerase chain reaction and element concentrations determined by inductively coupled plasma optical emission may be useful indices for estimating the PMI of victims under a wide range of environmental conditions. However, this study is a limited experimental research and not applicable to forensic cases as it is. Further studies of human bone with longer observation periods are required to verify these findings and to establish effective methods for PMI estimation.


2014 ◽  
Vol 1015 ◽  
pp. 570-573
Author(s):  
Xiao Juan Wei ◽  
Jian Ming Pan

A novel method for the determination of ruthenium in waste ruthenium-loaded carbon catalyst samples was established by inductively coupled plasma optical emission spectrometry after samples digested by Teflon pressure digestion vessel with aqua regia. Such experiment conditions were investigated as the influence of sample dissolution methods, digestion time, digestion temperature and interfering ions on the determination. Under the optimized conditions, the limit of detection (LODs) of Ru for tested solution was 9 ng mL-1. The relative standard deviations (RSDs) for Ru was 2.12 % (CRu= 1 mg L-1, n = 7). The linear range of calibration graph for Ru and Zn was 0 ~ 100.00 mg L-1. The proposed method was applied to determine the practical samples with good recoveries and satisfactory results.


2014 ◽  
Vol 1004-1005 ◽  
pp. 1281-1284
Author(s):  
Xiao Juan Wei ◽  
Zhi Quan Tian

A novel method for simultaneous determination of ruthenium and zinc in catalysts for hydrogenation of benzene to cyclohexene was established by inductively coupled plasma optical emission spectrometry after sample digestion by high temperature fusion with Na2O2. Such experiment conditions were investigated as the influence of sample digestion methods, fusion time, fusion temperature, the dosage of Na2O2and interfering ions on the determination. Under the optimized conditions, the limits of detection (LODs) of Ru and Zn for tested solutions were 11 and 13 ng mL-1, respectively. The relative standard deviations (RSDs) for Ru and Zn were 2.01 and 2.35 % (CRu, Zn= 1 mg L-1, n = 7), respectively. The linear ranges of calibration graphs for Ru and Zn were 0.05 ~ 100.00 mg L-1and 0.04 ~ 50.00 mg L-1, respectively. The proposed method was applied to determine catalyst samples with good recoveries and satisfactory results.


2014 ◽  
Vol 1033-1034 ◽  
pp. 603-606 ◽  
Author(s):  
Jian Ming Pan ◽  
Xiao Juan Wei

A technique for determination of Ru in waste ruthenium catalysts using ICP-OES after sample digestion by high temperature fusion with NaOH-NaNO3mixture was described. Such experiment conditions were investigated as the influence of sample digestion methods, fusion time, fusion temperature, the dosage of NaOH-NaNO3mixture and interfering ions on the determination. Under the optimized conditions, the limits of detection (LODs) of Ru for tested solutions were 10 ng mL-1. The relative standard deviations (RSDs) for Ru were 2.01 (CRu= 1 mg L-1, n = 7). The linear ranges of calibration graphs for Ru were 0 ~ 100.00 mg L-1. The proposed method was applied to determine the practical samples with good recoveries and satisfactory results.


2014 ◽  
Vol 1033-1034 ◽  
pp. 599-602
Author(s):  
Chun Miao Shi ◽  
Xiao Juan Wei

A novel method for the determination of platinum in waste platinum-loaded carbon catalyst samples was established by inductively coupled plasma optical emission spectrometry after samples digested by Teflon pressure digestion vessel with aqua regia. Such experiment conditions were investigated as the influence of sample dissolution methods, digestion time, digestion temperature and interfering ions on the determination. Under the optimized conditions, the limit of detection (LODs) of Pt for tested solution was 15 ng mL-1. The relative standard deviations (RSDs) for Pt was 2.35 % (CPt= 5 mg L-1, n = 7). The linear range of calibration graph for Pt was 0 ~ 150.00 mg L-1. The proposed method was applied to determine the practical samples with good recoveries and satisfactory results.


2021 ◽  
Vol 5 (1) ◽  
pp. 19-25
Author(s):  
Mariele Samuel Nascimento ◽  
Gabriel Toneto Druzian ◽  
Rochele Sogari Picoloto ◽  
Paola Azevedo Mello ◽  
Erico M. M. Flores

A method based on microwave-induced combustion (MIC) was applied for medicinal plants digestion allowing further chlorine determination by potentiometry using ion-selective electrode (ISE). Sample masses ranging from 500 to 1000 mg were evaluated for MIC digestion. Water and 10, 25, 50, and 100 mmol/L NH4OH were investigated as absorbing solutions. The accuracy of the proposed method was evaluated by using certified reference materials (CRMs), by recovery tests (500 µg/g), and also by comparison with the results obtained by inductively coupled plasma optical emission spectrometry (ICP-OES) after microwave-assisted alkaline extraction (MAE). Using water or NH4OH solutions (10 to 100 mmol/L), recoveries close to 100% and relative standard deviation lower than 5% were obtained. Results were in agreement with CRMs values (better than 95%) and also with those values obtained by using the MAE method. The main advantage of the proposed method was the complete combustion of high sample mass (1000 mg) resulting in low quantification limit (12.5 µg/g) and chlorine determination at low concentration by ISE. Another advantage of the proposed method was the high chlorine stability in digests (up to 30 days of storage) even using water as absorbing solution, which is in agreement with green analytical chemistry recommendations. Finally, the proposed MIC method was applied for commercial medicinal plants and the chlorine concentration was in the range of 59.4 ± 1.4 to 2038 ± 70 µg/g. The proposed MIC method was considered suitable for quality control for chlorine determination in medicinal plants.


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