Jung Ki Suh

Direct determination of arsine in gases by inductively coupled plasma-dynamic reaction cell-mass spectrometry.

Reliable determination of arsine (AsH(3)) in gases is of great importance due to stringent regulations associated with health, safety and environmental issues. It is, however, challenging for an analyst to determine trace airborne arsine concentrations without specifically designed collection procedures using adsorption, desorption, dissolution or impinging techniques. To circumvent such technical barrier, we have newly developed a direct analytical method, characterized by introduction of an arsine gas sample into stable plasma stream, followed by gas-phase oxidation of arsine with molecular oxygen in a dynamic reaction cell (DRC) equipped within the inductively coupled plasma-mass spectrometry (ICP/MS) system, followed by subsequent detection of AsO(+) ion. This preliminary work used trace arsine concentrations (161 microg m(-3), 322 microg m(-3), and 645 microg m(-3)) gravimetrically prepared in N(2) balance. The proposed method was optimized for the important experimental parameters such as the flow rates of the reaction gas, the arsine sample, and the carrier gas. This method was then validated by demonstrating good figure-of-merits including the low limit of detection (0.10 microg m(-3)), good linearity (r(2)>0.9915), low measurement uncertainty (0.66%), and high speed of analysis (<6 min). The proposed method is expected to be potentially applicable to the determination of arsine in real workplace air after appropriate modifications are made.

Quantitative analysis of Cu(In,Ga)Se2 thin films by secondary ion mass spectrometry using a total number counting method

The relative atomic fraction of Cu(In,Ga)Se2 (CIGS) films is one of the most important measurements for the fabrication of CIGS thin film solar cells. However, the quantitative analysis of multi-element alloy films is difficult by surface analysis methods due to the severe matrix effect. In this study, the quantitative analysis of CIGS films was investigated by secondary ion mass spectrometry (SIMS). The atomic fractions of Cu, In, Ga and Se in the CIGS films were measured by alloy reference relative sensitivity factors derived from the certified atomic fractions of a reference CIGS film. The total ion intensities of the constituent elements were obtained by a total number counting method. The atomic fractions measured by SIMS were linearly proportional to those certified by inductively coupled plasma mass spectrometry using an isotope dilution method. The uncertainties were determined from the standard uncertainties in the measurements and those of a CIGS thin film certified reference material.

Development of a Certified Reference Material (NMIJ CRM 7203-a) for Elemental Analysis of Tap Water

A certified reference material (CRM), NMIJ CRM 7203-a, was developed for the elemental analysis of tap water. At least two independent analytical methods were applied to characterize the certified value of each element. The elements certified in the present CRM were as follows: Al, As, B, Ca, Cd, Cr, Cu, Fe, K, Mg, Mn, Mo, Na, Ni, Pb, Rb, Sb, Se, Sr, and Zn. The certified value for each element was given as the (property value ± expanded uncertainty), with a coverage factor of 2 for the expanded uncertainty. The expanded uncertainties were estimated while considering the contribution of the analytical methods, the method-to-method variance, the sample homogeneity, the long-term stability, and the concentrations of the standard solutions for calibration. The concentration of Hg (0.39 μg kg-1) was given as the information value, since loss of Hg was observed when the sample was stored at room temperature and exposed to light. The certified values of selected elements were confirmed by a co-analysis carried out independently by the NMIJ (Japan) and the KRISS (Korea).

Final report of the key comparison CCQM-K88: Determination of lead in lead-free solder containing silver and copper

The CCQM-K88 key comparison was organized by the Inorganic Analysis Working Group of CCQM to test the abilities of the national metrology institutes to measure the mass fraction of lead in lead-free solder containing silver and copper. National Metrology Institute of Japan (NMIJ), National Institute of Metrology of China (NIM) and Korea Research Institute of Standards and Science (KRISS) acted as the coordinating laboratories. The participants used different measurement methods, though most of them used inductively coupled plasma optical emission spectrometry (ICP-OES) or isotope-dilution inductively coupled plasma mass spectrometry (ID-ICP-MS). Accounting for relative expanded uncertainty, comparability of measurement results was successfully demonstrated by the participating NMIs for the measurement of the mass fraction of lead in lead-free solder at the level of 200 mg/kg. It is expected that metals at mass fractions greater than approximately 100 mg/kg in lead-free solder containing silver and copper can be determined by each participant using the same technique(s) employed for this key comparison to achieve similar uncertainties mentioned in the present report. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Determination of Mercury in Fly Ash by Using Flow Injection Cold Vapor Isotope Dilution Inductively Coupled Plasma Mass Spectrometry

A method based on flow injection-isotope dilution-cold vapor-inductively coupled plasma mass spectrometry (FI-ID- CV-ICP/MS) has been applied to determine trace level of mercury in fly ash. 200 Hg isotopic spike was added to 0.25 g of BCR176R fly ash and then decomposed by microwave digestion procedure with acid mixture A (8 mL HNO3 +2m L HCl + 2 mL HF) and acid mixture B (8 mL HNO3 +2m L HClO4 + 2 mL HF) for applying IDMS. Mercury cold vapor was gener- ated by using reductant solution of 0.2% (w/w) NaBH4 and 0.05% (w/w) NaOH. The measurements of n( 200 Hg)/n( 202 Hg) isotope ratio was made using a quadrupole ICP/MS system. The accuracy in this method was verified by the analysis of certified reference material (CRM) of fly ash (BCR 176R). The indicative value of Hg in BCR 176R fly ash was 1.60 ± 0.23 mg/kg (k = 2). The deter- mined values of Hg in BCR 176R fly ash by the method of FI-CV-ID-ICP/MS described in this paper were 1.60 ± 0.24 mg/kg (k = 3.18) and the analysis results were in well agreement with the indicative value within the range of uncertainty.