火焰原子吸收分光光度法测定蔬菜中铜锌铅

蔬菜经过处理之后,在选定条件下,应用火焰原子吸收分光光度法同时测定蔬菜中铜、锌、铅的含量,方法简便、快速.三种元素的含量分别为0.5128 mg/Kg、0.8023mg/Kg、0.1028 mg/Kg,精密度RSD小于1.4%,加标回收率在92.3%～97.2%之间,结果令人满意.     

Cloud Point Extraction of Copper,Zinc, Iron and Nickel in Biological and Environmental Samples by Flame Atomic Absorption Spectrometry

Abstract

Cloud point methodology was successfully employed for preconcentration of trace copper, zinc, iron, and nickel prior to their determination by flame atomic absorption spectrometry (FAAS). The metals react with 2-phenyl-1H-benzo[d] imidazole (PHBI) in a surfactant Triton X-114 medium. The effects of analytical parameters including pH, amounts of reagents etc. were investigated on the recoveries of analytes. No influences were observed from the matrix ions. The detection limits (3SD_b/m) of 1.8, 2.8, 1.4, and 2.1 ng mL^?1 for Cu²⁺, Fe³⁺, Zn²⁺, and Ni²⁺, respectively. The method was applied to metal determination in various real samples. The validation of the procedure was carried out by analysis of a certified reference biological material, BCR 185 R liver samples.     

Determination of Ni and Zn in an Oil Matrix using Schiff Base‐Assisted Extraction Followed by a Flame Atomic Absorption Spectrometer: A Simple Strategy to Determine Ni and Zn

In the present work, a new and simple Schiff base‐assisted extraction strategy for Ni and Zn from an edible oil matrix with subsequent determination using a flame atomic absorption spectrometer was suggested. According to the green approach, laborious sample‐pretreatment procedures were eliminated via complexation of the analytes with N,N′‐bis(4‐methoxysalycylidene)‐2‐hydroxy‐1,3‐propanediamine (4MSHP) and transferred from the oil phase to the aqueous phase. The complexation properties of 4MSHP, Ni, and Zn were investigated using UV–vis spectrophotometry. The experimental conditions that affect the extraction efficiency were optimized using central composite design. The optimum conditions for the extraction of Ni and Zn were as follows: a volume to oil mass ratio of 0.83 to 1.31 mL g^?1 of 4MSHP solution; 62.3‐ and 50.6‐min, stirring time; 27.3 and 31.1 °C, temperature, respectively. The detection limits (3s_bm^?1) were 0.41 μg g^?1 for Ni and 0.16 μg g^?1 for Zn. Validation of the suggested work was performed by the analysis of organometallic standard‐doped n‐hexane solutions as certified reference materials under the optimum experimental conditions. The recovery percentages were warranted the accuracy and found as 98.2 ± 1.8% for Ni and 99.8 ± 1.2% for Zn. In addition, relative SD values were below 5% for both the analytes. The Student's t‐test showed that there was no significant difference between the found and doped amount of analytes at 95% confidence level. The features such as the detection technique, cheapness, eco‐friendly solvent usage, and practicality were better compared to the literature.     

Synthesis,X-ray Structure,Spectroscopic Properties and DFT Studies of a Novel Schiff Base

A series of Schiff bases, salicylideneaniline derivatives 1–4, was synthesized under mild conditions and characterized by ¹H NMR, HRMS, UV-Vis and fluorescence spectra, and single-crystal X-ray diffraction. In solid and aprotic solvents 1–4 exist mainly as E conformers that possess an intramolecular six-membered-ring hydrogen bond. A weak intramolecular C–H···F hydrogen bond is also observed in fluoro-functionalized Schiff base 4, which generates another S(6) ring motif. The C–H···F hydrogen bond further stabilizes its structure and leads it to form a planar configuration. Compounds 1–3 exhibit solely a long-wavelength proton-transfer tautomer emission, while dipole-functionalized Schiff base 4 shows remarkable dual emission originated from the excited-state intramolecular charge transfer (ESICT) and excited-state intramolecular proton transfer (ESIPT) states. Furthermore, the geometric structures, frontier molecular orbitals (MOs) and the potential energy curves for 1–4 in the ground and the first singlet excited state were fully rationalized by density functional theory (DFT) and time-dependent DFT calculations.     

一次溶样原子吸收光谱法检测地质样品银、铜、铅、锌的方法研究

通过实验探讨了一次溶样原子吸收光谱法检测地质样品中银、铜、铅、锌的有关问题的方法研究,改变了原来的分别溶样定容即操作繁琐浪费资源又延长了周期,而是采用一次王水溶样定容,达到了降低成本、简便、快速、准确的宗旨。     

Separation and Preconcentration of Trace Gallium and Indium by Amberlite XAD-7 Resin Impregnated with a New Hexadentates Naphthol-Derivative Schiff Base

Abstract

A new chelating polymeric sorbent has been developed using impregnation of Amberlite XAD-7 resin with a newly-synthesized hexadentates naphthol-derivative Schiff base 1-[(1E,9E)-10-(2-hydroxy-1-naphthyl)-4,7-dioxa-2,9-diaza-1,9-decadienyl]-2-naphth (EHND). The impregnated resin showed high binding affinity for Ga(III) and In(III) ions and was used for their preconcentration prior to determination by flame AAS. The optimum pH values for the quantitative sorption of Ga(III) and In(III) are 4.0–6.0 and 4.5–8.0, respectively, and their desorptions can be achieved by using 5 mL of 1 M HNO₃. The sorption capacities of the resin for gallium and indium were 1.1 and 1.3 mg g^?1, respectively. The enrichment factor for preconcentration of gallium and indium was found to be 200. The precision of the method, evaluated as the relative standard deviation obtained by analyzing a series of ten replicates, was below 2.5% for both elements. The practical applicability of the polymer was tested with synthetic seawater, natural waters, wastewater and human blood serum.