The slotted quartz tube has been applied to flow-injection flame atomic-absorption spec-trometry (FI-FAAS) showing several important advantages. The tube life was improved by a factor of 5d compared to conventional continuous aspiration. Flow impact systems were found not to be necessary ain the applications so that larger enhancement factors may be achieved without sacrifice in precision. For 1.0mg/l. copper, 1.0mg/l. lead, 0.1mg/l. cadmium and 1.0mg/l. gold sensitivity enhancement factors of 3.1, 5.5, 5.3 and 4.0 were obtained with precisions of 1.3%, l.l%, 1.6% and 1.7% RSD (n=11) respectively. Application of the slotted quartz tube FI-FAAS method to the determination of heavy metals in urine has shown improved tolerance to interfering matrices. Recoveries obtained by spiking undiluted urine samples with 0.1mg/l. copper and lead, and 0.01mg/l. cadmium were in the range lOO-102%.

A sequential injection system for on-line sorbent extraction preconcentration in electrothermal atomic absorption spectrometry was developed for the determination of trace cadmium in seawater and other water samples. The system is characterized by simple manifold design and improved robustness. The Cd-APDC complex was sorbed on a. 15-ml micro-column located at the tip of the furnace sampling probe packed with C. After sequentially metering 18 segments of ethanol, washing acid, sample and APDC complexing reagent into a 2.5-m-long, 1-mm-i.d. holding coil, the flow was reversed and directed to the column. The complexing reaction, sample loading and column washing were then achieved within the single reversed syringe stroke. The sorbed analyte was then eluted into the furnace with 50ml ethanol. Mutual mixing between sample, washing acid, and eluent were prevented by separating the zones with small air segments during metering. Progressive tightening of the column was avoided by a short back-suction through the column after each operational cycle. With 1ml sample loaded, and 50ml eluate introduced into the y1. furnace, an enrichment factor of 19 was obtained with a detection limit of 0.5ng l Cd 3s, a precision of 2.1%. y1 R.S.D. ns11, and a throughput of 12h. Good recoveries were obtained for spiked water samples and good agreement of results with standard reference seawater and river water samples were achieved.

对银的流动注射氨性样品溶液注入蒸气发生原子吸收光谱分析方法进行了初步研究。观察到银可在流动注射氨性样品溶液注入氢化物发生条件下生成挥发性气态物质。经过对银气态物质发生的化学条件，如样品溶液中氨的浓度，载流溶液的酸度，硼氢化钠浓度等以及流动注射参数如反应管道长度，载流和试剂溶液流速，载气流速等的优化，初步建立了银的氨性样品溶液注入流动注射蒸气发生原子吸收光谱分析方法。在500µl试样体积和120样/小时的采样频率下得到1.5µg/L银的检出限（3σ）,测定的RSD为2.6%（100µg/L, n = 11），初步研究了共存离子的干扰。对自来水，水库水中加入银的回收率为100-102%。同时对定影液中的的银进行了测定，并与火焰原子吸收进行了对照实验，结果基本相符。

Volatile species of Cu, Au and Tl were generated at room temperature by the reduction of NaBH4 in acidified aqueous medium using a flow injection vapor generation atomic absorption spectrometric (FI-VGAAS) system. 1, 10-phenanthroline, sodium diethanlydithiocarbonate (DDTC) and palladium (or combined with Rodamne B) ware used as enhancement reagents respectively. The normal flow injection peak shape wase obtained and the sensitivity were enhanced by 1-2 magnitude. The detection limits of 0.34-24ng/ml (3σ) were obtained with 300 or 500µl sample solution. The precision of 2.6-1.8% RSD were obtained with the sampling frequencies were of 120-180/h. The FI-VGAAS methods were used for the determination of copper in hair and rice sample and gold in the ore sample digests.

Gold in ores was determined by flame atomic absorption spectrometry following on-line preconcentration by sorbent extraction in a flow-injection system. The medium polarity adsorption resin Amberlite XAD-8 packed in a 220μ1 micro-column was used to collect gold (II1) from hydrochloric acid sample solutions for 40 s at 7.6ml/mm. Ethanol was used to elute the adsorbed analytes into the nebulizer. Optimization studies were made on sample loading rate, elution rate and sample acidity. Some possible interferences on the determination are discussed. A 35-fold enrichment was achieved at a sampling frequency of 60h-1 and with an RSD of 1.48. The detection limit (30) and 2. bg 1-l. Results for gold in ore samples showed good agreement with those obtained using activated carbon adsorption preconcentration. The recoveries were 97-108s.