离子色谱法测定盐酸吉西他滨药品中的氟

分别用过硫酸钾湿消解法、过硫酸钾加压湿消解法、双氧水加压湿消解法、干灰化法对盐酸吉西他滨进行氧化处理,将有机氟转化为无机氟,用离子色谱法测定氟离子含量,间接测得盐酸吉西他滨中的总氟量。实验考量了过硫酸钾、氢氧化钠和双氧水的用量。在选择的样品预处理方法和色谱条件下,后3种方法转化率达到88.9%～98.6%,回收率为89.4%～105%,在此基础上,建立了盐酸吉西他滨药品中总氟的定量测定方法,F-含量在0.1～10 mg/L的浓度范围内呈线性,线性回归系数为0.9996,相对标准偏差为2.4%,检测限为0.01 mg/L。     

碱融浸取–离子选择电极法测定固体废物中的总氟

采用氢氧化钠熔融浸取固体废物中的氟,用离子选择电极法测定其中的总氟含量。固体废物样品经氢氧化钠高温熔融后,以热纯水浸取并加入适量的盐酸使溶液呈弱碱性,去除主要干扰离子。测定氟的线性范围为5.00~500μg,线性相关系数r=0.999 6,检出限为12.5 mg/kg。6种类型固体废物样品的加标回收率在90.4%~110.0%之间,测定结果的相对标准偏差为2.3%~4.6%(n=6)。该方法样品预处理简单、重现性好、检出限低,适用于多种固体废物中总氟的测定。     

离子选择电极法测定食品添加剂硫酸钙中的氟离子

建立了氟离子选择性电极对食品添加剂硫酸钙中氟离子含量的测定方法,通过标准曲线法进行定量,线性相关系数为0.999 1,线性范围为0.2~3.0μg/mL,方法的相对标准偏差为3.2%,加标回收率为97.8%~102.0%,实验结果表明所建立的方法简单、快速、准确,适用于食品级硫酸钙中氟离子含量的测定。     

微波消解-氟离子选择电极法测定树叶中氟离子含量

采用微波消解处理样品,氟离子选择电极法测定了树叶中氟离子含量;通过正交实验考察了微波功率、消解时间、固液比、冷却时间等条件对微波消解的影响,对消解试剂和微波消解条件进行了筛选和优化。结果表明,其相对标准偏差小于0.46%,加标回收率在95.5%~103.3%之间。该法简单快速、准确可靠,对测定植物树叶中氟离子含量十分有效。     

碱熔-水蒸气蒸馏-离子色谱法测定锌精矿中的氟

建立了一种测定锌精矿中氟含量的分析方法。通过碱熔半熔融方法,除去锌精矿中大量硫对样品前处理的影响,利用水蒸气蒸馏的方法分离了被测元素氟与矿石中其它大量重金属离子。通过碱熔-水蒸气蒸馏后离子色谱测定,最大限度排除干扰,降低测定检出限。以碳酸钠(2.5mmol/L)和碳酸氢钠(3.5mmol/L)混合溶液作为淋洗液,SH-AC-1(200mm×4.6mm ID)阴离子分析柱分离,抑制电导检测器检测。线性范围内相关系数为0.999 6,加标回收率97%~102%,相对标准偏差小于4.0%,样品检出限0.0004%。有效拓展了锌精矿中氟含量的测定范围。     

离子选择性电极法测定离子液体中的氟离子

旨在探究是否可以利用离子选择性电极法对1-己基-3-甲基咪唑四氟硼酸盐(HmimBF4)离子液体复合材料中的氟离子进行测定。得到线性响应范围是pF值为0.5～5,最适pH值为6,其检出下限为1×10~(-5) mol/L,精密度为0.75%,测得离子液体的氟离子浓度为0.19 mol/L,加标回收率为97.2%～103.2%。结果表明,离子选择性电极法具有实际操作简单、响应时间短、加标回收率高、精密度高、准确度好等优点,所以可用于样品的测定。     

氟离子选择电极法测定含铜蚀刻废液中氟含量方法探讨

准确测定含铜蚀刻废液中氟含量是含铜蚀刻废液中铜盐回收的关键,本文就含铜蚀刻废液中氟含量离子选择电极测定方法^[1～3]进行探讨与验证。通过样品前处理与试验,离子选择电极一次标准加入法测定下限为0.9mg·L^-1,离子选择电极标准曲线法测定下限为1.2 mg·L^-1;两种方法的相对标准偏差在1.2%～1.7%,两种方法的加标回收率在77%～102%,满足工程应用要求。     

离子选择电极法测定对氟聚苯乙烯聚合体中的氟含量

本文研究了分解对氟聚苯乙烯聚合体的条件,建立了用离子选择电极法测定对氟聚苯乙烯聚合体中氟含量的方法,对氟苯甲酸加标回收率为９９．９％,对氟聚苯乙烯分析结果的相对标准偏差为２．７％,方法简便,准确。     

超声萃取-离子色谱法测定建设用砂石中氟、氯、硫酸根离子

建立超声萃取-离子色谱法测定建设用砂石中氟、氯、硫酸根离子的方法.砂石样品用超纯水超声萃取并离心,上清液经固相萃取柱净化,经0.22μm水系PES滤膜过滤,采用离子色谱法测定滤液中氟、氯、硫酸的含量,以外标法定量.3种阴离子的质量浓度在0～50 mg/L范围内与色谱峰面积线性良好,线性相关系数均大于0.999.检出限为...     

超声辅助离子液体液相微萃取-高效液相色谱法分析水样中加替沙星或氟罗沙星

建立了一种采用离子液体1-己基-3-甲基咪唑六氟磷酸([C6mim][PF6])为萃取剂,超声辅助离子液体液相微萃取-高效液相色谱法分析水样中加替沙星和氟罗沙星的方法。 实验考察了溶液酸度、离子液体用量等因素对萃取的影响。在pH值分别为3.3、2.1的加替沙星和氟罗沙星水样中,加入0.4 mL [C6mim][PF6],超声,离心,离子液体相直接用于HPLC进行分析。 该方法的线性范围为0.5~50 mg/L,测定加替沙星和氟罗沙星的相对标准偏差(n=5)为2.80%和5.93%,二者的检出限分别为0.46、0.97 μg/L,该方法萃取水样中加替沙星的加标回收率为80.5%~89.5%,氟罗沙星的加标回收率可达93.3%~99.0%。     

海洛因滥用者毛发中毒品代谢物的固相萃取-GC/MS分析

考察了采用固相萃取技术时毛发中海洛因毒品及其代谢物的原形释放方法。通过对海洛因吸食者毛发和空白添加标准品毛发的碱消解、酸消解、甲醇超声提取、甲醇-5 mol/L HCI超声提取、甲醇-TFA超声提取5种毛发中毒品及其代谢物的释放方法考察,确立了甲醇超声提取-固相萃取-气相色谱/质谱-选择离子检测的方法为稳定、有效的海洛因滥用者毛发中毒品及其代谢物的释放与检测方法。利用该方法对添加6-单乙酰吗啡的毛发进行萃取和测试,6-单乙酰吗啡的回收率为78.7%,相对标准偏差RSD为2.4%,该方法可有效地检出海洛因滥用者毛发中的6-单乙酰吗啡。     

毛发中海洛因代谢物的释放与分析方法研究

通过对海洛因吸食者毛发和空白添加标准品毛发的碱消解、酸消解、甲醇超声提取、甲醇-5 mol/L HCl超声提取、甲醇-三氟乙酸超声提取5种毛发中毒品及其代谢物的释放方法考察,确立了甲醇超声提取-液液萃取-气相色谱/质谱-选择离子检测的方法.本方法可最大程度地抑制海洛因的中间代谢物6-单乙酰吗啡的水解,其水解率仅为2.63%,极大地提高了海洛因滥用的毛发证据作用.利用本方法对添加6-单乙酰吗啡的毛发进行萃取和检测,6-单乙酰吗啡的回收率为52.6%,相对标准偏差RSD为4.6% ;对添加不同浓度的吗啡、可待因、6-单乙酰吗啡3种毒品的毛发进行萃取和检测,其线性良好(r＞0.99),相对标准偏差均小于15%.此外,考察了甲醇消解的影响因素,吸毒者毛发中的毒品释放效果随毛发的细碎程度和超声时间延长而提高.     

火焰原子吸收光谱法测定尘铅前处理方法的研究

采用火焰原子吸收光谱法测定尘铅样品,在0-1．00mg／L范围内样品中铅含量与吸光度呈良好线性关系,检出限为2．88μg／m^2（按定容体积50mL、采样体积400L计）。采取酸煮法、索氏提取法、微波消解法、超声波提取法等4种前处理方法,在0．100,0．500,1．00mg3个质量水平对空白滤筒进行加标回收试验,4种前处理方法的回收率和测定结果的相对标准偏差分别为91．8％-97．4％,2．2％～3．2％;83．0％-86．8％,7．4％-10．3％;93．6％-97．2％,2．5％～3．7％;89．3％-90．9％,3．2％～4．5％,提取效果以酸煮法和微波消解法最佳,超声波提取法次之,索氏提取法最差。     

In vitro evaluation of Cu and Fe bioavailability in cashew nuts by off-line coupled SEC-UV and SIMAAS

In this work Cu and Fe bioavailability in cashew nuts was evaluated using in vitro method. Extractions with simulated gastric and intestinal fluids and dialysis procedures were applied for this purpose. The proteins separation and quantification were performed by size exclusion chromatography (SEC) coupled on-line to ultra-violet (UV) and off-line to simultaneous multielement atomic absorption spectrometry (SIMAAS). The SEC-UV and SIMAAS profiles of the protein fractions obtained by alkaline extraction (NaOH) and precipitation with HCl indicated the presence of high and low molecular weight species in the range between >75 kDa and 9.3 kDa. Almost 83% of Cu and 78% of Fe were extracted during cashew nut digestion and 90% of both elements were dialyzed. With these results it is possible to assume that 75% of Cu and 70% of Fe present in cashew nut could be bioavailable. The SEC-UV and SIMAAS chromatographic profiles obtained after in vitro gastrointestinal digestion reveal that Cu and Fe not dialyzed can be associated to a compound of 9.2 kDa.     

微波消解同时衍生化GC-MS法测定血浆中脂肪酸的研究

研究了利用微波能对样品进行加热, 以Ｈ２ＳＯ４ － 甲苯－ 甲醇体系作衍生化试剂, 在消化的同时对血浆中的脂肪酸进行衍生化, 然后用ＧＣ－ ＭＳ 法测定血浆中脂肪酸。 对微波功率、微波加热时间、消解及衍生化试剂等条件进行了优化, 测定结果较好。该法整个消化及衍生化过程只需２ ｍｉｎ , 与传统方法相比大大缩短了实验操作时间, 特别适用于大量样品的测定。     

微波消解衍生化气相色谱-质谱法测定鲨鱼软骨中的脂肪酸

 研究了用微波技术消解衍生化气相色谱 质谱法 (GC MS)快速测定鲨鱼软骨中脂肪酸的分析方法。用正交设计试验优化消解衍生化条件 ,以盐酸 甲醇 (体积比为 1∶4)体系作消解衍生化溶液 ,在 60 0W微波功率作用下加热 4min进行样品的前处理 ,将样品的消解、脂肪酸的衍生化及脂肪酸甲酯的萃取融于一体。方法具有灵敏度高、省时、省试剂、操作方便等特点。该法适用于大批量固体样品中脂肪酸的测定。     

Determination of selected polychlorinated biphenyls in soil by miniaturised ultrasonic solvent extraction and gas chromatography-mass-selective detection

Miniaturised ultrasonic solvent extraction procedure was developed for the determination of selected polychlorinated biphenyls (PCBs) in soil samples by gas chromatography-mass-selective detection by using 2³ factorial experimental design. Recoveries of PCBs from fortified soil samples are over 90% for three different fortification levels between 40 and 120 μg kg⁻¹, and relative standard deviations of the recoveries are below 7%. The limits of detection (LODs) ranged from 0.003 to 0.006 μg kg⁻¹. The performance of the proposed method was compared to traditional shake flask extraction method on the spiked real soil sample and extraction methods showed comparable efficiencies. Proposed miniaturised ultrasonic solvent extraction offers several advantages, i.e., reducing sample requirement for measurement of target compound, less solvent consumption and reducing the costs associated with solvent purchase and waste disposal.     

GC-MS法测定ABS木塑材料中十溴二苯醚

建立了索氏提取和超声萃取-GC-MS法测定丙烯腈-丁二烯-苯乙烯共聚物(ABS)木塑材料中十溴二苯醚的分析方法。通过正交试验分析提取溶剂、样品质量和提取时间三个因素的显著性,并优化了参数。在优化条件下,索氏提取和超声萃取法的平均回收率均大于80%,精密度均小于10%。经F检验和T检验显著性统计,两种前处理方法的精密度和准确度不存在差异。相对于传统的索氏提取法,超声萃取法具有操作简单、溶剂用量少和省时的特点,可以较好的应用于木塑材料中十溴二苯醚检测。     

Direct extraction of alkylphenols, chlorophenols and bisphenol A from acid-digested sediment suspension for simultaneous gas chromatographic-mass spectrometric analysis

The direct extraction of alkylphenols, chlorophenols and bisphenol A from an acid-digested sediment suspension for GC-MS analysis was studied. The sediment was digested with acid while the hydrolyzed analytes were being extracted with dichloromethane. The conditions of the acid digestion and extraction were optimized in terms of time, acidity of digestion, and extracting solvent. It is possible to complete the extraction within 20 min with 5 ml of 0.1 M HCl digesting solution and three portions of 5 ml of dichloromethane. The recoveries of analytes were mostly around 90% with about 10% relative standard deviations. With this technique parallel treatment of large numbers of sediment samples is possible without any expensive special equipment or heating process. The analytical characteristics of this extraction technique were compared with Soxhlet extraction and the pressurized liquid extraction technique. The technique was examined and evaluated for real environmental sediment samples and certified reference material of natural matrix.     

Comparison of ultrasound-assisted extraction and microwave-assisted digestion for determination of magnesium, manganese and zinc in plant samples by flame atomic absorption spectrometry

In this paper, a sample preparation method based on acid extraction of magnesium, manganese and zinc from plant tissue by means of high intensity probe ultrasonication is described. Acid extracts obtained upon sonication were directly nebulised into an air-acetylene flame for fast metal determination by atomic absorption spectrometry. Parameters influencing extraction such as sonication time, ultrasound amplitude, sample mass, particle size, extractant composition and volume were fully optimised. Optimum conditions for metal extraction were as follows: a 3-min sonication time, a 30% ultrasonic amplitude, a 0.1-g sample mass, a particle size less than 50 mum, a 0.3% m/v HCl concentration in the extractant solution and a 5-ml extractant volume. Six plant samples used in the human diet were analysed, the concentration range of the three metals approximately being in the range of 1500-3000 mug g(-1) for Mg, 30-735 mug g(-1) for Mn and 20-45 mug g(-1) for Zn. Limits of detection corresponding to the ultrasound-assisted extraction method were 0.10, 1.26 and 0.65 mug g(-1) for Mg, Mn and Zn, respectively. Between-batch precision, expressed as R.S.D., was about 0.5, 1.5 and 1% for Mg, Mn and Zn, respectively. Analytical results for the three metals by ultrasound-assisted extraction and microwave-assisted digestion showed a good agreement, thus indicating the possibility of using mild conditions for sample preparation instead of intensive treatments inherent with the digestion method. The advantages and drawbacks of ultrasound-assisted extraction in respect to the microwave-assisted digestion are discussed.