Leal L O, Elsholz O, Forteza R, Cerdà V
Department of Chemistry, University of the Balearic Islands, Carretera de Valldemossa km.7.5, E-07122 Palma de Mallorca, Spain.
Anal Chim Acta. 2006 Jul 28;573-574:399-405. doi: 10.1016/j.aca.2006.04.078. Epub 2006 May 5.
A new software-controlled time-based multisyringe flow injection system for mercury determination by cold-vapor atomic absorption spectrometry is proposed. Precise known volumes of sample, reducing agent (1.1% SnCl2 in 3% HCl) and carrier (3% HCl) are dispensed into a gas-liquid separation cell with a multisyringe burette coupled with one three-way solenoid valve. An argon flow delivers the reduced mercury to the spectrometer. The optimization of the system was carried out testing reaction coils and gas-liquid separators of different design as well as changing parameters, such as sample and reagents volumes, reagent concentrations and carrier gas flow rate, among others. The analytical curves were obtained within the range 50-5000 ng L(-1). The detection limit (3sigma(b)/S) achieved is 5 ng L(-1). The relative standard deviation (R.S.D.) was 1.4%, evaluated from 16 successive injections of 250 ng L(-1) Hg standard solution. The injection and sample throughput per hour were 44 and 11, respectively. This technique was validated by means of solid and water reference materials with good agreement with the certified values and was successfully applied to fish samples.
提出了一种新的软件控制的基于时间的多注射器流动注射系统，用于通过冷蒸气原子吸收光谱法测定汞。将精确已知体积的样品、还原剂（3%盐酸中1.1%的氯化亚锡）和载气（3%盐酸）通过与一个三通电磁阀相连的多注射器滴定管分配到气液分离池中。氩气流将还原后的汞输送到光谱仪中。通过测试不同设计的反应线圈和气液分离器以及改变诸如样品和试剂体积、试剂浓度和载气流量等参数来对系统进行优化。分析曲线在50 - 5000 ng L⁻¹范围内获得。实现的检测限（3σ(b)/S）为5 ng L⁻¹。相对标准偏差（R.S.D.）为1.4%，由对250 ng L⁻¹汞标准溶液进行16次连续进样评估得出。每小时的进样量和样品通量分别为44和11。该技术通过固体和水标准物质进行了验证，与认证值吻合良好，并成功应用于鱼类样品。
