Development of sensitive analytical methods for bismuth determination by atomic spectrometric techniques

Development of sensitive and economical analytical methods for determination of bismuth (Bi) by using flame atomic absorption spectrometry (FAAS) and improvement the sensitivity of inductively coupled plasma optical emission spectrometry (ICP-OES) for Bi were the main purposes of the thesis.An uncoated slotted quartz tube (SQT) device with two slots with an angle of 180° with respect to each other was used for sensitivity improvement in the initial stages of research. Uncoated SQT was also used for atom trapping (SQT-AT) studies. Then, several coating materials were used to modify the surface of SQT. These coatings materials were selected among the metals or metal oxides with relatively high melting and boiling points to assure their persistence on the surface of SQT during analytical procedures. Experimental variables such as acetylene flow rate, sample suction rate, height of SQT from burner, type and volume of organic solvent for revolatilization of Bi from SQT and trapping time of Bi solution in were optimized. By using double slotted SQT, sensitivity of FAAS was improved as 2.9 times.Further improvement in sensitivity was achieved using SQT as atom trapping device. It was decided to use of 50.0 µL of methyl ethyl ketone for the revolatilization of Bi from SQT surface. Using the optimum parameters, linear calibration range was determined as 7.5-100.0 ng mL-1 for Bi. Enhancement, E, with respect to FAAS was found as 256 by SQT-AT-FAAS. By considering the 6.0 min collection of Bi solution at 6.0 mL min-1 sample flow rate Et and Ev values were calculated as 43 min-1 and 7.1 mL-1, respectively.Non-volatile elements, Mo, Zr, W and Ta were tried as coating metal for SQT. It was observed that W coated SQT gave the highest absorption signal for Bi. LOD and LOQ were calculated as 0.14 and 0.46 µg mL-1, respectively. Enhancement factor was calculated as 4.0 with respect to FAAS.W coated SQT was also used as trapping device for Bi in FAAS. Trapping of Bi for 5.0 min at sample flow rate of 5.5 mL min-1, LOD and LOQ were calculated as 0.51 ng mL-1 and 1.7 ng mL-1, respectively. Characteristic concentration was calculated as 1.4 ng mL-1. Enhancement, E, with respect to FAAS was 613.The possible interference effects of the various cations and anions were investigated for SQT-AT-FAAS and W coated SQT-AT-FAAS. The accuracy of the techniques was checked by analyzing a standard reference material of simulated fresh water (NIST 1643e).In addition, SQT devices with different inner and outer diameters were tested in order to investigate the possible effect on Bi singal depending on the wall thickness of the tube. Variation in Bi signal depending on length of upper slit was also investigated.Experimental and instrumental variables in CF-HG-ICP-OES were optimized for Bi determination. LOD and LOQ were found as 0.16 ng mL-1 and 0.53 ng mL-1, respectively. 12 times improvement with respect to conventional ICP-OES from slope ratio of linear calibration plots was achieved by optimizing of CF-HG-ICP-OES. Possible interferences effects of Cd, Co, Cu Fe, Ni, As, Hg, Sn and Sb ions in the determination of Bi by CF-HG-ICP-OES were investigated.