Karadjova Irina B, Lampugnani Leonardo, Tsalev Dimiter L
Faculty of Chemistry, University of Sofia, 1 James Bourchier Blvd., Sofia 1164, Bulgaria.
Talanta. 2005 Feb 28;65(4):1015-21. doi: 10.1016/j.talanta.2004.08.035.
Analytical procedures for electrothermal atomic absorption spectrometric (ETAAS) determination of arsenic in essential oils from lavender (Lavendula angustifolia) and rose (Rosa damascena) are described. For direct ETAAS analysis, oil samples are diluted with ethanol or i-propanol for lavender and rose oil, respectively. Leveling off responses of four different arsenic species (arsenite, arsenate, monomethylarsonate and dimethylarsinate) is achieved by using a composite chemical modifier: l-cysteine (0.05gl(-1)) in combination with palladium (2.5mug) and citric acid (100mug). Transverse-heated graphite atomizer (THGA) with longitudinal Zeeman-effect background correction and 'end-capped' graphite tubes with integrated pyrolytic graphite platforms, pre-treated with Zr-Ir for permanent modification are employed as most appropriate atomizer. Calibration with solvent-matched standard solutions of As(III) is used for four- and five-fold diluted samples of lavender and rose oil, respectively. Lower dilution factors required standard addition calibration by using aqueous (for lavender oil) or i-propanol (for rose oil) solutions of As(III). The limits of detection (LOD) for the whole analytical procedure are 4.4 and 4.7ngg(-1) As in levender and rose oil, respectively. The relative standard deviation (R.S.D.) for As at 6-30ngg(-1) levels is between 8 and 17% for both oils. As an alternative, procedure based on low temperature plasma ashing in oxygen with ETAAS, providing LODs of 2.5 and 2.7ngg(-1) As in levender and rose oil, respectively, and R.S.D. within 8-12% for both oils has been elaborated. Results obtained by both procedures are in good agreement.
本文描述了用电热原子吸收光谱法（ETAAS）测定薰衣草（Lavendula angustifolia）和玫瑰（Rosa damascena）精油中砷的分析方法。对于直接ETAAS分析，薰衣草油和玫瑰油样品分别用乙醇或异丙醇稀释。通过使用复合化学改进剂：l-半胱氨酸（0.05g l(-1)）与钯（2.5μg）和柠檬酸（100μg）结合，实现了四种不同砷形态（亚砷酸盐、砷酸盐、一甲基砷酸盐和二甲基砷酸盐）的响应平稳。采用纵向塞曼效应背景校正的横向加热石墨原子化器（THGA）和带有集成热解石墨平台的“端盖”石墨管，并用Zr-Ir进行预处理以进行永久改性，作为最合适的原子化器。分别用As(III)的溶剂匹配标准溶液对薰衣草油和玫瑰油的四倍和五倍稀释样品进行校准。较低的稀释倍数需要通过使用As(III)的水溶液（用于薰衣草油）或异丙醇溶液（用于玫瑰油）进行标准加入校准。整个分析过程的检测限（LOD）在薰衣草油和玫瑰油中分别为4.4和4.7ng g(-1) As。两种油中As在6 - 30ng g(-1)水平时的相对标准偏差（R.S.D.）在8%至17%之间。作为一种替代方法，详细阐述了基于在氧气中低温等离子体灰化结合ETAAS的方法，该方法在薰衣草油和玫瑰油中的检测限分别为2.5和2.7ng g(-1) As，两种油的R.S.D.在8%至12%之间。两种方法获得的结果吻合良好。
