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Determination of traces of metals in gases is achieved by using a combination of a Pyrex Gas Washing System and ICP-MS methods. A special purge and blank installation is designed to clean the system with purified Helium (6N). Three 125-ml bubbler tubes in series with a 20 ml of nitric acid (~20%) are used to capture the metals carbonyl in carbon monoxide. The metals dissolved in nitric acid are analyzed by ICP-MS (Agilent 7500ce). This method is able to achieve detection limits down to 1×10 mol/mol. Theoretically, the detection limits could go lower, but they are typically limited due to sample contamination. The experimental results show that this method provides a cost-effective approach to measure the traces of metals in gases quickly and accurately. Introduction Determination of traces of metals (10~10) mol/mol in gases is a routine and important task in many fields. Existence of traces of metals in gases will affect quality of many products, especially in semiconductor manufactories. However, metals are almost present in all gases and it is very difficult to obtain a “standard” gas containing absolutely “zero” metals. Meanwhile, fast determination of the traces of metals in gases with high accuracy is especially necessary when reactive standard mixtures gases are involved. As such, development of a rapid, less sample consuming, cost effective and more precise method to detect traces of metals in gases is the focus of this paper. There are some ways to determine traces of metals carbonyl in gases. However, most of them are either qualitative or semi-quantitative methods due to limitations of the conventional effective and reliable calibration methods using the standard traces of metals mixtures gases, especially when these mixtures are almost impossible to prepare in the required concentrations. The determination of traces of metals carbonyl in carbon monoxide is introduced in this paper by using the combination of a Pyrex Gas Washing System and ICP-MS methods (Abbreviated: PGWS-ICP-MS). The experimental results show that this method can be used to determine simultaneously most of traces of metals carbonyl in carbon monoxide. Experimental Reagents and Equipment Reagent: Water, double-distilled and de-ionized. Nitric acid, 70% (w/v) HNO3, redistilled in glass. Nitric acid, 20% (w/v) HNO3, was prepared by adding 1428 ml of 70% (w/v) HNO3 to distilled water followed by dilution to 5000 ml. Nickel and Iron stock solutions, i.e. [Ni] =100 μg /ml, and [Fe]=100 μg /ml respectively were prepared by dissolving 0.1000 g pure Ni and 0.1000 g pure Fe in minimum volume of 70% HNO3, followed by dilution to 100 ml with 20% (w/v) HNO3. Fresh calibration stock solution, with Ni=50 ng/ml, and Fe = ng/ml was prepared by diluting 0.5ml Nickel and Iron stock solution (100 μg/ml) to 1000 ml in a volumetric flask with 20% HNO3 on a week basis. 2nd Annual International Conference on Advanced Material Engineering (AME 2016) © 2016. The authors Published by Atlantis Press 1341 Helium (6N), high purity purging gas in cylinder with a two-stage regulator. The blank of 2% (w/v) nitric acid for Fe is 11 ng/ml and for Ni is 0.61ng/ml, respectively. Equipment: 1. Sampler: Pyrex Gas Washing System (see figure 1). 2. Pressure reduce regulator, coarse metering valve, flow meter, wet test meter, stopwatch, cylinders. 3. ICP-MS, Aglient 7500ce, limit of detection, for Fe is 0.01 ng/g, and for Ni is 0.03 ng/g. Process and Calculation Experimental installation is constructed according to Fig.1. Before the three 125 ml bubbler tubes (7 in series in figure 1) filled with 20.0 ml of nitric acid (~20%), the high purity helium (6N) is used to purge the system completely, usually 1 ~2 hours, then with a three ways valve switch to carbon monoxide cylinder (the sample,5N). In the sample line, the flow rate is fixed at 500 ml/min, the tubing diameter is 3.2 mm and the height of the acid the gas need to penetrate through is 3/4 of the solution level. The bubble size is about(1~3)mm,.The metals carbonyl in carbon monoxide are captured in three bubbler tubes (numbered 1, 2 and 3), and move to the volumetric flasks in series As1, As2 and As3. The flasks are washed thoroughly to collect droplets from aerosols in the parts of the bubbler tubes and tubing, with the wash-out being diluted to 200 ml with double-distilled and de-ionized water by ICP-MS measurement. The blanks (A0i) are prepared the same way as sampling except for using high purity Helium (6N purging gas) instead of carbon monoxide. The results can be calculated with the following equations:

Determination of Nickel and Iron Carbonyl in Carbon Monoxide by ICP-MS Methods and a Pyrex Gas Washing System