Determination of Lead in Lipstick by Direct Solid Sampling High-Resolution Continuum Source Graphite Furnace Atomic Absorption Spectrometry: Comparison of Two Digestion Methods

A new analytical procedure for the determination of lead in lipstick has been developed using direct solid sampling high resolution continuum source graphite furnace atomic absorption spectrometry (SS HR CS GFAAS). The performance of this method has been compared to acid digestion methods for sample preparation, with or without hydrofluoric acid (HF) with inductively coupled plasma mass spectrometry (ICP-MS) detection. Good reliability was obtained for all three methods; the results obtained for certified reference materials with concentrations between 1 and 20 ppm were in agreement with the certified values. However, for materials with complex matrices, such as pearl or Ca-Na borosilicate, only ICP-MS with HF sample digestion or AAS with direct solid sampling allowed complete recovery of lead. To avoid the use of hazardous acids, the development of SS HR CS GFAAS is an interesting alternative. With the AAS method, a characteristic mass of 13.2 pg of lead was obtained, and the limit of detection was 0.005 µg/g. The performance of the method was evaluated by determining lead in lipstick. The use of the solid sampling technique constitutes a good alternative for accurate and rapid determination of lead content in lipstick and cosmetic raw materials, with a suitable limit of detection and a reduced risk of contamination or of analyte loss. Another alternative would be to use ICP-MS determination in conjunction with microwave-assisted acid digestion without the use of HF, which implies accepting a quantification of “nearly total” lead, closer to a “bio-extractible” fraction.     

微波消解ICP-MS法测定广西北部湾海鸭蛋中硒和锗的含量

以硝酸-过氧化氢（体积比为5：3）混合溶液为消解剂,微波消解法处理海鸭蛋样品,采用电感耦合等离子体质谱法测定样品溶液中的硒和锗的含量。选择适合的同位素元素,运用碰撞室技术（CCT）降低多原子离子对元素硒、锗的干扰,用钇作为在线内标。硒、锗工作曲线的线性范围均为0．0-100．0ng／mL,相关系数r=0．9996;硒、锗的检出限分别为1．1,0．15ng／mL,测定结果的相对标准偏差分别为4．78％,5．70％（n=6）,加标回收率为92．2％-104．0％。用该法测定国家标准物质黄鱼（GBW08573）中硒的含量,测定值在标称值范围内。     

体积排阻高效液相色谱-电感耦合等离子体质谱法测定海产贝类中镉的形态

运用体积排阻高效液相色谱-电感耦合等离子体质谱联用技术(SEC-HPLC-ICP-MS)分析了高镉积累扇贝和低镉积累菲律宾蛤仔中镉的存在形态,并结合体外全仿生消化技术,研究了在唾液、胃、肠无机物和有机物(含消化酶)作用下,扇贝和菲律宾蛤仔中镉的主要存在形态.结果发现:扇贝中Cd总量约为菲律宾蛤仔的10倍;在扇贝中检测到3种Cd形态:金属硫蛋白(MT)-Cd、谷胱甘肽(GSH) Cd和半胱氨酸(Cys)-Cd;在菲律宾蛤仔中检测到2种Cd形态:MT-Cd和GSH-Cd;以峰面积作参考进行比较,扇贝中MT-Cd和GSH-Cd含量分别约为菲律宾蛤仔的5 6和2.0倍.结合体外全仿生模型发现,在扇贝胃全仿生提取液中,检测到1种未知小分子有机镉形态(Cd-X),在扇贝肠全仿生提取液中检测到4种Cd形态,其中MT-Cd是主要形态;而在菲律宾蛤仔胃、肠全仿生提取液中均仅检测到1种未知小分子有机态镉(Cd-X).本实验证明贝类中的MT-Cd,GSH-Cd,Cys-Cd中络合的Cd在生物体胃肠消化液作用下会发生解离.     

密封恒温分光光度法快速测定化学需氧量

建立了密封恒温消解样品,测定化学需氧量（CDDcr)的分光光度法。应用正交试验法确定了密封恒温法消解试样的最佳条件,此方法有机物的氧化率为98.33%-99.50%。CODcr值在0-800mg/mL范围内符合比耳定律。样品测定的相对标准偏差为0.39%（n=12),加标回收率为97.50%-99.56%。用该法测得的CODcr值与标准回流法所得结果一致。     

微波消解光度法测定催化剂中镍

采用微波消解系统消解催化剂样品,考察了微波消解时酸的用量、消解时间、功率和压力对消解效果的影响,选择了微波消解的最佳工作参数。用常规吸光光度法测定催化剂中镍含量,其相对误差小于3.6%,相对标准偏差（n=5)小于2.2%,与常压溶样方法测定的结果吻合。试验表明,该方法省时、省酸,操作简单,减少沾污,改善工作环境,是一种有效的实用方法。     

微波消解氢化物发生ICP—AES法测定川山紫中痕量硒

建立了微波消解连续氢化物发生ICP AES法测定川山紫中痕量硒的方法 ,系统地研究了微波消解、氢化物发生的最佳条件 ,方法简便快速 ,检出限为 0 .0 0 38μg·ml- 1,RSD为 1.13% (n =10 ,0 .5 4 7μg·g- 1Se) ,样品加标回收率为 99.2 4 %。     

微波溶样ICP-AES法测定甘肃东紫苏中的无机元素

将正交试验和方差分析应用于微波溶样ICP-AES法测定东紫苏地上部分K, Na, Ca, Ba, Pb, Zn, Mn, Cu, Mg, Fe和Al等无机元素的分析中,此方法简单、快速、灵敏度高、准确性好,且多种元素可同时测定,该方法的加标回收率为93.2%～104.1%, RSD(n=5)＜3.20%。结果表明: 东紫苏中含有丰富的对人体有益的微量元素,此结果可为探讨东紫苏中元素含量与其药效的相关性提供理论依据。     

Physicochemical,Antioxidant, Microstructural Properties and Bioaccessibility of Dark Chocolate with Plant Extracts

In this study, dark chocolates (DCh) containing zinc lactate (ZnL) were enriched with extracts from elderberries (EFrE), elderflowers (EFlE), and chokeberries (ChFrE) to improve their functional properties. Both dried plant extracts and chocolates were analyzed for antioxidant capacity (AC) using four different analytical methods: 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), cupric ion-reducing antioxidant capacity (CUPRAC), and ferric-reducing antioxidant power (FRAP), while total phenolic content (TPC) was determined by Folin–Ciocalteu (F–C) assay. An increase in antioxidant properties of fortified chocolates was found, and the bioaccessibility of their antioxidants was evaluated. The highest AC and TPC were found in ChFrE and chocolate with chokeberries (DCh + ChFrE) before and after simulated in vitro digestion. Bioaccessibility studies indicated that during the simulated digestion the AC of all chocolates reduced significantly, whereas insignificant differences in TPC results were observed between chemical and physiological extracts. Moreover, the influence of plant extracts on physicochemical parameters such as moisture content (MC), fat content (FC), and viscosity of chocolates was estimated. Furthermore, scanning electron microscopy with dispersive energy spectroscopy (SEM-EDS) was used to analyze surface properties and differences in the chemical composition of chocolates without and with additives.     

微波消解-电感耦合等离子体质谱法测定茶叶中的稀土元素

应用微波消解,不经分离富集,用ICP-MS直接测定了9种茶叶中的15种痕量稀土元素．9种茶叶中轻稀土元素质量浓度较高,其质量浓度占被测稀土总质量浓度的80％以上．除陈香礼普和杭产绿茶稀土元素质量浓度相对较高外,其它茶叶品种闻无明显的差异性．稀土元素的检出限均小于10ng·L^-1,各元素测定的RSD（n=6）为1．85％～19．4％,样品加标回收率为97．1％～99．6％．     

微波消解-电感耦合等离子体质谱法测定丙烯腈-丁二烯-苯乙烯共聚物塑料中的铅、镉、汞、铬、砷

建立了微波消解技术-电感耦合等离子体质谱(ICP-MS)法同时测定丙烯腈-丁二烯-苯乙烯共聚物(ABS)塑料中的铅、镉、汞、铬、砷五种元素的方法。对仪器的参数设置、进样系统进行了优化,并对此类塑料样品中上述元素分析的前处理条件,如消解体系、消解温度、恒温时间以及酸用量等进行了优化。方法检出限为0.7～6.5 ng·g-1;用加标回收的方法评价了该方法的准确性,加标回收率为89.8%～110.8%;样品测定相对标准偏差为2.8%～11.3%。该方法检出限低、精确度好、准确度高、简单快速、无需基体匹配。