Papers by Keyword: Flame Atomic Absorption Spectrometry

Abstract: The influence of different acidic medium, including hydrochloric acid, nitric acid and perchloric acid on the absorbance of sodium by flame atomic absorption spectrometry was studied. The results showed that the effects of acidic medium and water on the determination of sodium were as follows: hydrochloric acid > perchloric acid > nitric acid > water. Acid effect changed with the increase of acid concentration, however, the absorbance value of sodium element decreased when the concentration of acid was higher than 1%~2%. This effect was more obvious for high content of sodium. The detection limits, repeatability and recovery of the samples under the three acidic medium were compared. The optimum acid conditions were determined and the sensitivity of the method was improved.

Abstract: The determination method for analyzing trace copper in vanadium alloy by flame atomic absorption spectrometry was investigated in the paper. The sample digestion method, digestion acidity, determination conditions, matrix interferences, method precision, recovery of standard addition were investigated in detail. The method precision in RSD% was 8.6%, and the average recoveries of standard addition were from 93.9% to 95.6%. The experimental results indicated that the proposed method for determination of trace copper in vanadium alloy was simple, fast, accurate, and easy to operate, which was suitable for quality control of vanadium alloy.

Abstract: In this paper, a manual-controlled injection nanometer calcium titanate based on glass fiber filter enricher (MICTE) was prepared, and its application in speciation of Cr (III) and Cr (VI) was studied. The optimum experimental parameters for separation of the Cr (III) and Cr (VI) have been investigated. The results showed that the MICTE had adsorption capacity towards the Cr (III) and Cr (VI). And two forms of chromium show different adsorption capacities at different pH values, Cr (III) could be adsorbed at pH 9, but Cr (VI) cant be adsorbed. Whereas Cr (VI) retained at pH 3, but Cr (III) cant be adsorbed. Therefore, it is possible that the two forms of chromium are complete separated. The Cr (III) and Cr (VI) could be completely eluted with 1 mol·L¹ HCl and 1 mol·L¹NaOH, respectively. The chromium concentration was measured by atomic absorption spectroscopy. A new method for determination of the speciation of chromium in environmental water samples based on the manual-controlled injection enricher and atomic absorption spectroscopy determination was proposed. The method was successfully applied for the determination of Cr (III) and Cr (VI) in environmental waters with satisfactory results.

Abstract: A new method of preconcentration with nanometer-strontium titanate immobilized on aluminum oxide (ASTO) combined with flame atomic absorption spectrometry (FAAS) was proposed for the determination of trace heavy metal ions, included Cu²⁺, Ni²⁺ and Ag⁺, in environmental water. The optimum experimental parameters for preconcentration of the heavy metals studied, such as pH, shaking time, eluent and coexisting ions, have been investigated. The results showed that Cu²⁺, Ni²⁺ and Ag⁺, could be quantitatively retained by the ASTO in the pH range of 5-8, and then eluted completely with 2 mol·L^-1 HNO₃. The detection limits of this method for Cu²⁺, Ni²⁺ and Ag⁺ were 0.031μg·L^-1, 0.15μg·L^-1and0.041μg·L^-1 with an enrichment factor of 50, respectively. The method has been applied to the simultaneous determination of trace amounts of Cu²⁺, Ni²⁺ and Ag⁺ in environmental water, the recoveries were all in 95%-105%.

Abstract: Temperature-controlled HNO3-H2O2 wet digestion and flame atomic absorption spectrometry (FAAS) were employed in the determination of mineral elements in the fermented liquid residue of livestock dung. The 8 most common mineral elements-K, Na, Fe, Mn, Cu, Zn, Ca and Mg-in fermented liquid were selected for analysis, and the experimental results showed that the correlation coefficient (r) of each mineral element’s quantitative standard curve was >0.9993, the quantitation limit was 0.90-67.0 ng/L, the relative standard deviation (RSD) was 0.79%-2.51%, and the standard addition recovery rate was 95%-103%. It was found that the average content of the 8 mineral elements in fermented liquid was in a descending order of K, Na, Ca, Mg, Fe, Mn, Zn and Cu.

Abstract: A new method for the separation and preconcentration of Chrome and Manganese using potassium titrationate whisker was developed prior to the determination by FAAS. The influences of analytical parameters including amount of sorbent, the adsorption capacity, the coexistence ion influence and the adsorption behavior were also studied by the flame atomic absorption spectrometry, the effects of concomitant ions were also examined. The detection limits (3s) were 15ng•mL^-1 and 44 ng•mL^-1. The method was applied to the determination of analytes in real samples, such as tea and environmental samples, etc. and good results were obtained(relative standard deviations93%).

Abstract: A sensitive method has been developed for the speciation of Cr(III) and Cr(VI) in natural water using a porous nano-barium-strontium titanate by sorghum straw template method (SPBST) and flame atomic absorption spectrometry (FAAS). The procedure presented based on Cr(III) and Cr(VI) show different adsorption capacities on the SPBST at different pH values, that is, Cr (III) selectively retained at pH 13, but Cr(Ⅵ) can’t be adsorbed. Whereas Cr (VI) retained at pH 1, but Cr(Ⅲ) can’t be adsorbed. Hence, Cr(Ⅵ) and Cr(Ⅲ) can be separated through changing pH value of medium. Cr(Ⅵ) and Cr(Ⅲ) adsorbed on the SPBST can be completely eluted using 1•0 mol•L⁻¹ NaOH and 1.0 mol•L⁻¹ HCl, respectively. And Cr(Ⅵ) and Cr(Ⅲ) were determined by FAAS, The preconcentration factor of the method was 100. At the optimum conditions determined experimentally, the adsorption capacities were calculated to be 21.6 mg•g⁻¹ and 7.3 mg•g⁻¹, respectively. The proposed method was applied to the determination and speciation of chromium in tap water, lake water and wastewater samples with satisfactory results.

Abstract: The micro-column packed with porous nano-barium- strontium titanate microspheres, joining with injector, a new manual-controlled injection porous nano-barium- strontium titanate microspheres enricher (PBSTME) was prepared. The enrichment capability of the PBSTME for the heavy metal ions, such as zinc, nickel, copper, manganese, cobalt and silver was investigated. The results showed that all the heavy metals studied could be quantitatively retained by the PBSTME in the pH range of 5–8, and then eluted completely with 2 mol•L^-1 HNO₃. The detection limits of this method for zinc, nickel, copper, manganese, cobalt and silver ions were 0.028 μg•L^-1, 0.2μg•L^-1, 0.031 μg•L^-1, 0.022 μg•L^-1, 0.057μg•L^-1 and 0.039 μg•L^-1 with an enrichment factor of 50, respectively. A new method has been developed for the determination of trace heavy metal ions based on pre-concentration with a PBSTME prior to their determination by flame atomic absorption spectrometry. The method has been applied to the simultaneous determination of trace amounts of zinc, nickel, copper, manganese, cobalt and silver ions in water sample with satisfactory results.

Abstract: A manual-controlled injection barium-strontium titanate based on glass fiber filter enricher(MIBSTE) was prepared, and its application in speciation of Cr(III) and Cr(VI) from water was studied. The optimum experimental parameters for preconcentration and separation of the Cr(III) and Cr(VI) have been investigated. The results showed that the BBST had adsorption capacity towards the Cr(III) and Cr(VI) at the different conditions. And two forms of chromium show different adsorption capacities at different pH values, Cr (III) could be adsorbed at pH ≥ 10, but Cr(VI) can’t be adsorbed. Whereas Cr (VI) retained at pH ≤ 2, but Cr(III) can’t be adsorbed. Therefore, it is possible that the two forms of chromium are complete separated. The Cr(III) and Cr(VI) could be completely eluted with 1 mol•L⁻¹ HCl and 1 mol•L⁻¹ NaOH, respectively. The chromium concentration was measured by atomic absorption spectroscopy. A new method for determination of the speciation of chromium in environmental water samples based on the manual-controlled injection enricher and atomic absorption spectroscopy determination was proposed. The method was successfully applied for the determination of Cr(III) and Cr(VI) in environmental waters with satisfactory results.

Abstract: A preconcentration method based on the adsorption of palladium-dimethylglyoxime -anchored organobentonite (DMG-bentonite) for the determination of palladium at trace levels by flame atomic absorption spectrometry (AAS) has been developed. The optimum experimental parameters for the adsorption and preconcentration of the palladium, such as pH value of medium, contact time, eluent and coexisting ion, have been investigated. The results showed that the palladium ion could be quantitatively retained by the DMG-bentonite in the pH range of 3–5 using citric acid/citrate buffer, the adsorption time was 20 min, and capability of adsorption was 8.73 mg•g-1. The palladium ion adsorbed on the DMG-bentonite could be completely eluated by using 1 mol•L-1 HCl. The detection limits of this method for palladium was 1.02µg•L-1 with an enrichment factor of 60. The method has been applied to the determination of trace amounts of palladium ion in street dust and environmental water with satisfactory results.