Molecular fluorescence spectrometry, resonance Rayleigh scattering and gas chromatography-mass spectroscopy（GC-MS） were used to study the effect of pure fish serum albumin（FSA） as the model protein on the extracti...Molecular fluorescence spectrometry, resonance Rayleigh scattering and gas chromatography-mass spectroscopy（GC-MS） were used to study the effect of pure fish serum albumin（FSA） as the model protein on the extraction of three chlorobenzenes（CBs： 1,3-DCB, 1,2-DCB and 1,2,4-TCB; DCB=dichlorobenzene; TCB=trichlorobenzene） in fish samples. The results show that there was a strong binding effect between CB and FSA. In an aqueous solution of 90%（volume fraction） acetone, a slow but full protein denaturation might take place, which would cause the unfolding of protein and the releasing of CBs. Based on these results, a QuEChERS（quick, easy, cheap, effective, rugged and safe） method was modified by replacing the traditional acetonitrile with acetone aqueous solution in the present work. This modified QuEChERS method was applied in the determination of CBs in fish samples. The spiked recoveries and the limits of detection were 80.4%--118.3% and 2.4--7.3 ng/g, respectively. This paper proposes a new strategy by slowing down the protein denaturation and releasing bound organic compounds to enhance the extraction efficiency of CBs in fish samples.展开更多
A simple, environmentally friendly and high efficient extraction method was proposed for the determina- tion of five phthalates in aquatic products by gas chromatography combined with mass spectrometry detector （GC-M...A simple, environmentally friendly and high efficient extraction method was proposed for the determina- tion of five phthalates in aquatic products by gas chromatography combined with mass spectrometry detector （GC-MS）. When this method was adopted, samples were pretreated by modified QuEChERS（quick, easy, cheap, effective, rugged and safe） method. An environmentally friendly extractant（ethanol aqueous solution） replaced toxic acetonitrile for extracting phthalates in the protein-matrix samples. Fluorescence quenching spectra of bovine serum albumin（BSA） with phthalates show that there was a high-affinity interaction between phthalate and protein, de- creasing the extraction efficiency of phthalates from fish samples. However, in the 80%（volume fraction, ~） ethanol aqueous solution, a slow but full protein denaturation takes place, which would cause the unfolding of protein and the release of phthalates. Meanwhile, the fat-soluble impurities are extracted less in ^（ethanol） 80% aqueous solution than in either ~p（ethanol） 100% or hydrophobic solvents in the liquid-liquid extraction procedure. Therefore the puri- fication steps were greatly simplified. Overall recoveries were 81.77%--90.5% with limits of detection between 2.53 and 9.61 ~tg/L, and relative standard deviation values at 1.15%---4.85%. The proposed approach was satisfactorily applied to the determination of phthalates in real aquatic products, such as fish, shrimp and oyster.展开更多
目的以丹参为研究对象,比较2020年版《中华人民共和国药典》中3类前处理方法对33种禁用农药残留物回收率的影响,进一步优化快速样品处理法(quick,easy,cheap,effective,rugged and safe,QuEChERS)。方法分别从基质效应和回收率方面比较...目的以丹参为研究对象,比较2020年版《中华人民共和国药典》中3类前处理方法对33种禁用农药残留物回收率的影响,进一步优化快速样品处理法(quick,easy,cheap,effective,rugged and safe,QuEChERS)。方法分别从基质效应和回收率方面比较《中华人民共和国药典》3类前处理方法,并对QuEChERS法进行研究与优化,样品加水后由1%醋酸-乙腈提取,依次加入QuEChERS盐包与QuEChERS净化管盐析净化,提取液经浓缩后分别加入水和内标磷酸三苯酯,结合液相色谱-串联质谱法和气相色谱-串联质谱法以添加水平为定量限浓度水平测定样品的回收率和RSD。结果采用《中华人民共和国药典》前处理方法时,丹参中33种禁用农药(54个单体)在添加水平为定量限浓度水平时,部分农药回收率较低;优化QuEChERS法后,丹参中33种禁用农药(54个单体)在一定浓度下,线性关系良好,r均大于0.990,其回收率为64.43%~127.35%时,RSD均<15%;199批饮片和60批药材中共检出2种农药,甲拌磷检出率为3.86%,克百威检出率为1.93%,但残留量均未超过2020年版《中华人民共和国药典》规定限度。结论优化后的QuEChERS法快速简便,有针对性地对丹参中33种禁用农药残留进行准确检测,对于丹参的生产种植与日常监控具有一定的参考意义。展开更多
A rapid analytical method was first developed to detect organophosphorus pesticides(OPPs)in cereals,which used dynamic microwave assisted extraction(DMAE)coupled online with a modified quick,easy,cheap,effective,rugge...A rapid analytical method was first developed to detect organophosphorus pesticides(OPPs)in cereals,which used dynamic microwave assisted extraction(DMAE)coupled online with a modified quick,easy,cheap,effective,rugged,and safe(QuEChERS)method.Cereals samples were mixed with a certain amount of quartz,Ci8 and the primary second amine(PSA),and extracted successively with the acetonitrile-water solution(80%,VIV)under microwave irradiation.The obtained eluate was directly introduced into a collection tube containing NaCl and MgSO4.Finally,the supemate was evaporated and reconstructed,and determined by gas chromatographic spectrometry.Some factors affecting the experimental results were studied and optimized.The extraction and purification processes were carried out coinstantaneously and 12 samples could be treated in one step in 4 min.Low limits of tection(0.43—1.31 p.g/kg)for OPPs were obtained in cereals.The relative standard deviations(RSDs)were 2.1%—9.3%.The recoveries of OPPs ranged from 76.1%to 100.2%.By combining the advantages of DMAE with QuEChERS,the sample pretreatment process was simple to operate,with little amount of organic solvent.The whole extraction process was completed in a closed environment,therefore it was very appropriate for daily analysis of OPPs in cereals.展开更多
基金Natural Science Foundation of Shandong Province,China
文摘Molecular fluorescence spectrometry, resonance Rayleigh scattering and gas chromatography-mass spectroscopy（GC-MS） were used to study the effect of pure fish serum albumin（FSA） as the model protein on the extraction of three chlorobenzenes（CBs： 1,3-DCB, 1,2-DCB and 1,2,4-TCB; DCB=dichlorobenzene; TCB=trichlorobenzene） in fish samples. The results show that there was a strong binding effect between CB and FSA. In an aqueous solution of 90%（volume fraction） acetone, a slow but full protein denaturation might take place, which would cause the unfolding of protein and the releasing of CBs. Based on these results, a QuEChERS（quick, easy, cheap, effective, rugged and safe） method was modified by replacing the traditional acetonitrile with acetone aqueous solution in the present work. This modified QuEChERS method was applied in the determination of CBs in fish samples. The spiked recoveries and the limits of detection were 80.4%--118.3% and 2.4--7.3 ng/g, respectively. This paper proposes a new strategy by slowing down the protein denaturation and releasing bound organic compounds to enhance the extraction efficiency of CBs in fish samples.
基金Supported by the National Natural Science Foundation of China（No.20973149） and the Natural Science Foundation of Shandong Province, China（No.ZR2011BM009）.
文摘A simple, environmentally friendly and high efficient extraction method was proposed for the determina- tion of five phthalates in aquatic products by gas chromatography combined with mass spectrometry detector （GC-MS）. When this method was adopted, samples were pretreated by modified QuEChERS（quick, easy, cheap, effective, rugged and safe） method. An environmentally friendly extractant（ethanol aqueous solution） replaced toxic acetonitrile for extracting phthalates in the protein-matrix samples. Fluorescence quenching spectra of bovine serum albumin（BSA） with phthalates show that there was a high-affinity interaction between phthalate and protein, de- creasing the extraction efficiency of phthalates from fish samples. However, in the 80%（volume fraction, ~） ethanol aqueous solution, a slow but full protein denaturation takes place, which would cause the unfolding of protein and the release of phthalates. Meanwhile, the fat-soluble impurities are extracted less in ^（ethanol） 80% aqueous solution than in either ~p（ethanol） 100% or hydrophobic solvents in the liquid-liquid extraction procedure. Therefore the puri- fication steps were greatly simplified. Overall recoveries were 81.77%--90.5% with limits of detection between 2.53 and 9.61 ~tg/L, and relative standard deviation values at 1.15%---4.85%. The proposed approach was satisfactorily applied to the determination of phthalates in real aquatic products, such as fish, shrimp and oyster.
文摘目的以丹参为研究对象,比较2020年版《中华人民共和国药典》中3类前处理方法对33种禁用农药残留物回收率的影响,进一步优化快速样品处理法(quick,easy,cheap,effective,rugged and safe,QuEChERS)。方法分别从基质效应和回收率方面比较《中华人民共和国药典》3类前处理方法,并对QuEChERS法进行研究与优化,样品加水后由1%醋酸-乙腈提取,依次加入QuEChERS盐包与QuEChERS净化管盐析净化,提取液经浓缩后分别加入水和内标磷酸三苯酯,结合液相色谱-串联质谱法和气相色谱-串联质谱法以添加水平为定量限浓度水平测定样品的回收率和RSD。结果采用《中华人民共和国药典》前处理方法时,丹参中33种禁用农药(54个单体)在添加水平为定量限浓度水平时,部分农药回收率较低;优化QuEChERS法后,丹参中33种禁用农药(54个单体)在一定浓度下,线性关系良好,r均大于0.990,其回收率为64.43%~127.35%时,RSD均<15%;199批饮片和60批药材中共检出2种农药,甲拌磷检出率为3.86%,克百威检出率为1.93%,但残留量均未超过2020年版《中华人民共和国药典》规定限度。结论优化后的QuEChERS法快速简便,有针对性地对丹参中33种禁用农药残留进行准确检测,对于丹参的生产种植与日常监控具有一定的参考意义。
基金Supported by the National Key R&D Program of China(No.2018 YFD040013).
文摘A rapid analytical method was first developed to detect organophosphorus pesticides(OPPs)in cereals,which used dynamic microwave assisted extraction(DMAE)coupled online with a modified quick,easy,cheap,effective,rugged,and safe(QuEChERS)method.Cereals samples were mixed with a certain amount of quartz,Ci8 and the primary second amine(PSA),and extracted successively with the acetonitrile-water solution(80%,VIV)under microwave irradiation.The obtained eluate was directly introduced into a collection tube containing NaCl and MgSO4.Finally,the supemate was evaporated and reconstructed,and determined by gas chromatographic spectrometry.Some factors affecting the experimental results were studied and optimized.The extraction and purification processes were carried out coinstantaneously and 12 samples could be treated in one step in 4 min.Low limits of tection(0.43—1.31 p.g/kg)for OPPs were obtained in cereals.The relative standard deviations(RSDs)were 2.1%—9.3%.The recoveries of OPPs ranged from 76.1%to 100.2%.By combining the advantages of DMAE with QuEChERS,the sample pretreatment process was simple to operate,with little amount of organic solvent.The whole extraction process was completed in a closed environment,therefore it was very appropriate for daily analysis of OPPs in cereals.
