The masking effects of NaF,8-hydroxygquinoline and citric acid on the atomic fluorescence signals of Sb(Ⅲ) and Sb(Ⅴ),and the method for eliminating the masking effect of citric acid were investigated.The results show that 0.10 mol/L citric acid has the strongest masking effect on Sb(Ⅴ) and can increase the sensitivity of Sb(Ⅲ),and 10g/L KI+10g/L thiourea can completely eliminate the masking effect of citric acid in >5h.Based on this,a method for analyzing the valent speciation of Sb in cosmetics by hydride generation atomic fluorescence spectrometry(HGAFS) was developed.The samples were extracted twice with 0.10ml/L citric acid.The supernatant was removed by centrifugation and the residues were merged as extract solution.After the acidification of the extract solution,the Sb(Ⅲ) content was determined directly.Then the extract solution was added with KI(10g/L)+ thiourea(10g/L) and set aside for >5h before the total content of Sb(Ⅴ) and Sb(Ⅲ) was determined.The Sb(Ⅴ) content was obtained by subtracting Sb(Ⅲ) from the total content.The detection limit(3σ) was 0.32 μg/L,the quantification limit(10σ) was 1.0μg/L,and the spiked recovery was in the range of 70%~130%,for both Sb(Ⅲ) and Sb(Ⅴ).There was a little conversion from Sb(Ⅲ) to Sb(Ⅴ) in this experiment.

A new method for the determination of cadmium in apple and apple tablets was developed and validated based on direct cadmium analyzer with the atomic fluorescence spectroscopy.In this paper,we elaborate on the the mechanism of the determination.The porous graphite tube as the electrothermal vaporization has been applied for a sample introduction.Both accuracy and precision were evaluated using the reference material and samples and they can meet the demand.The detection limit of the instrument was less than 1 pg and RSD was less than 5%

A method to determine the content of fifths inorganic anions in DIANP by ion chromatography was established.After added acetonitrile and water,the sample was passed though the On Guard Ⅱ RP column to wipe off DIANP and other organic compound then was determined directly.The separation was performed with KOH as isocratic mobile phase at a flow rate of 1.0mL/min and accomplished with a Dionex IonPac AS11-HC column.The calibration curve of DIANP was linear,results showed that correlation of fifths anions were higher than 0.999.The relation standard deviation were 1.57%～4.30%,NO-2,N-3,NO-3,SO2-4 the recoveries were 89.3%～98.6%.The method was simple,rapid and satisfaction.

A method for the determination of arsenic in banknote printing ink by graphite furnace atomic absorption spectrometry was proposed.The sample was treated by microwave assisted sample digestion with a mixture of HNO_3-H_2O_2, and determined with nickel nitrate as matrix modifier.Under the optimum experimental conditions, linear relationship between values of mass concentration and absorbance of arsenic was obtained in the range within 20μg·L~(-1) , with detection limit (3s/k)of 0.84μg·L~(-1).Values of recovery found by addition standard method were in the range of 92.5%-104.3%.

Atomic Fluorescence Spectrometry Speciation analyzer(SA-10)is an instrument based on HPLC-HGAFS technique.Its analytical performance for species of antimony and mercury is that the limit of detection (LOD)of Hg(Ⅱ),MetHg,EtHg,Sb(Ⅲ)and Sb(Ⅴ)is 0.5,0.3,0.4,1 and 5μg/L respectively;and the linearity range is 0.5～1000,0.3～1000,0.4～1000,1～1000 and 5～1000μg/L respectively;the linear correlation ratios(R)are all more than 0.9990;the relative standard deviations(RSD)are all less than 5.0%. This paper focuses on the applications of speciation analysis for mercury species in sea products,environment water, soils and speciation analysis for antimony species in cosmetics.

Sample of transparent glass hollow-ware was soaked in HOAc(4+96) to dissolve antimony from the sample.GFAAS was used to determine the amount of antimony eroded from the hollow-ware within definite time of soaking.Cupric ion solution was added as matrix modifier and background correction with deuterium lamp was adopted in GFAAS determination.Matching method was used in preparation of calibration curve and blank solution to compensate the error arisen from the presence of acetic acid.Conditions of the temperature elevation program,especially the temperature for ashing and atomization,were tested and optimized.Linear relationship between values of absorbance and mass concentration of antimony was obtained in the range within 20 μg·L-1.Detection limit(3S/b) and characterization concentration of the method found for antimony were 0.483 μg·L-1 and 0.396 pg/1% respectively.Test for recovery was made by standard addition method,and values of recovery found were in the range of 93%-104%.

A method for the rapid determination of apple juice mingled with pear juice was proposed by a portable Raman spectrometer combined with chemometrics.The Raman shift for pear juice was the same as that for apple juice,and the functional groups and vibrational modes obtained for the Raman spectra of fruit juice were given.Slight differences of the Raman signals at 866 cm-1 and 1 126 cm-1 were found between the spectra of apple juice and pear juice,which may be due to the difference of fructose isomers content.Based on the presented method,19 apple juices and pear juices were easily distinguished by four different kernel functions of support vector machines(SVM).A mathematical model with SVM was established to analyze the content of pear juice added to apple juice.The relative errors for most of the analyzed samples were less than 10%.

Through optimizing the conditions of samples extraction、chromatographic separation、postcolumn preparation and testing conditions for HGAFS,a method for As(III)、As(V)、Sb(III) and Sb(V) simultaneous determination was developed.And we focused on the extraction of Sb without species transformation,and the conditions of postcolumn pretreatment of Sb(V)-citric complexes.The results showed that Sb species commutative transformation ratio was the lowest in 50mmol/L citric acid + 50mmol/L sodium citric buffer solution;the results also showed that the extracted Sb(V)-citric complexes could be reduced to Sb(III)-citric acid complexes with HCl and KI on line added.The limit of detection(LOD) for As(III)、As(V)、Sb(III) and Sb(V) was 2.4、3.1、0.5 和 5.0 μg/L respectively;and linearity range was 2.4～1000、3.1～1000、0.5～1000 and 5～1000μg/L respectively;Linear correlation ratios(R) were all more than 0.9990;relative standard deviations(RSD) were all less than 3.0%.The powder,liquid,solid cosmetics determined by this method,the spiked recoveries were between 77% and 110%.It was proved that the method was fit to determine species of As and Sb simultaneously in cosmetics.

The sample of aluminum ingot or alloy was dissolved with HCl-HNO_3(3-1-1),and the contents of arsenic and mercury were determined by HG-AFS.Influential factors,including negative high-voltage,lamp current,the rates of carrier and shield gases,matrix spectrum of aluminium,pH of solution,and concentration of NaBH_4 were studied and optimized.The detection limits(3S/N) of arsenic and mercury found were 0.055 and 0.006 2 rng.L~(-1),and values of RSD's(n=6) were less than 2.5%.The proposed method was applied to the analysis of samples of aluminium ingots and aluminium alloys,and recovery was tested by standard addition method, giving results in the range of 93.3%-103.3 for arsenic and 93.3%-106.7%for mercury.

A method of plumbane generation combined with atomic fluorescence spectrometry for the determination of Pb in health-care drugs prepared from organs or tissues of deer was reported in this paper.The sample was digested with HNO_3-HClO_4 and Pb(Ⅱ) in the sample solution was then determined by plumbane generation combined with atomic fluorescence spectrometry.Under the selected conditions,recovery of the method was in range of 91%-108%,detection limit was 0.395 μg·L-1 and RSD was 1.2%.

提出了用离子色谱/电导检测法测定苹果汁中的亚硝酸盐、硝酸盐和硫酸盐的方法;采用IonPac AS11-HC阴离子交换分离柱、30mmoL/L氢氧化钾作流动相,自动再生抑制型电导检测器ASRS-4mm,建立起针对苹果汁中亚硝酸盐、硝酸盐和硫酸盐离子色谱分析方法,该方法有良好的线性(相关系数为99.92%～99.97%)和重复性(相对标准偏差小于3%)及准确性(回收率为89.5%～97.0%)。检出限分别为:亚硝酸盐(NO2)1mg/kg,硝酸盐(NO3)2mg/kg,硫酸盐(SO4)2mg/kg。

ICP-AES determination of Ca,Cu,Fe,K,Mg,Mn,Na,Zn and P in milk powder was reported in this paper.Conditions of sample digestion with HNO3 by microwave heating were studied.Various working parameters of the instrument were optimized and described in detail.Four kinds of milk powder were analyzed by the present method,giving results checked quite well with the results obtained by the standard method(GB/T 5413).Results of recovery test obtained were in the range of 96.5%-111.1%.

[目的]建立一种快速测定食品中铅含量的方法.[方法]采用微波消解样品,原子荧光光谱法测定铅元素.[结果]消解所用试剂显著减少,操作简便,快速高效,空白值低,结果准确可靠.[结论]本法简单、准确、经济、可靠、快速,适用于各类食品.

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