Analytical application of liquid adsorption chromatography of metal chelates

Journal of Liquid Chromatography & Related Technologies

Kodani

Fujii

2009

A selective and sensitive determination method for mercury (Hg) ions in river water by reversed phase high performance liquid chromatography (HPLC) has been developed. Two mL of water sample containing Hg(II) ions was put into a 4 mL sample tube. To the sample tube, 500 mL of 2 mol=L (M) acetate buffer solution (pH 4.5), and 50 mL of 0.01 M 2-mercaptopyrimidine (MP) were added to form a neutral Hg chelate. The Hg chelate subsequently became preconcentrated in a reversed phase mini column. By switching the valve, the Hg chelate was separated and detected at 255 nm. These processes occur automatically, except for the addition of water samples, buffer, and MP solutions. The correlation coefficients of the calibration curves obtained with 2 mL of mercury standard were more than 0.999 over the range of 20 ng=mL (ppb) to 10 mg=mL (ppm). The detection limit of Hg ions in 2 mL solution was 1.6 ppb, which corresponded to 3 times the standard deviation (N ¼ 10) of the blank peak area. Effects of foreign ions on the determination of 0.2 ppm Hg were investigated with 57 metal ions. Almost none of the ions interfered except for Au(III), Pd(II), Ag(I), and Co(II) ions. The recoveries with spiked river water samples for 5, 0.5, and 0.05 Hg ion (N ¼ 7) were 99.7 AE 0.4%, 100.3 AE 0.3%, and 100.7 AE 0.7%, respectively.

Section: Effects Of Foreign Ionsmentioning

confidence: 99%

Section: Selective and Sensitive Determination Of Mercury(ii) Ions Inmentioning

confidence: 99%

Selective and Sensitive Determination of Mercury(II) Ions in River Water by an Automatic HPLC System Combined with On-Line Column Enrichment as 2-Mercaptopyrimidine Chelate

Journal of Liquid Chromatography & Related Technologies

Kodani

Fujii

2009

“…On the other hand, the application of high-performance liquid chromatography (HPLC) for the separation and determination of metal ions has increased in recent years. [1][2][3][4][5] HPLC is a very popular and inexpensive apparatus, and operation of the HPLC is easy. In addition, a more sensitive quantitative analysis is possible by combining pre-column derivatization HPLC with a simple solvent extraction.…”

Section: Introductionmentioning

confidence: 99%

Selective Determination of Gold Ion in River Water by Solvent Extraction With 2-Thiazolidinethione, 4-(1-Methylethyl)-, (4s)-, Followed by Reversed Phase HPLC

Journal of Liquid Chromatography & Related Technologies

2012

& A determination method for gold (Au) ion in river water has been developed by reversed phase HPLC. The Au(III) ion was quantitatively extracted into benzene from a weak alkaline solution as 2-thiazolidinethione, 4-(1-methylethyl)-, (4S)-(TTM) chelate. The extracted Au-TTM chelate was then separated on a C 18 column with an eluent of methanol=ethanol= 0.01 mol=L TTM (70:30:0.1, v=v) and detected at 270 nm. The correlation coefficients of the calibration curves obtained with 5 mL Au standards were more than 0.999 in the range of 1 lg=mL (ppm) to 10 ppm. The detection limit of the Au ion in 5 mL of water was estimated as 0.08 ppm, by a signal-to-noise ratio (S=N) ¼ 3. Relative standard deviations of peak areas (n ¼ 6) for 5 ppm Au standards was 1.0%. The recoveries with a spiked river water sample for 5 ppm Au ion (n ¼ 6) was 99.2 AE 0.6%. Effects of foreign ions on the determination of 2 ppm Au were investigated with 57 metal ions. Almost none of the ions interfered except for Ag(I), Cd(II), and Ti(IV) ions.

“…On the other hand, the application of high performance liquid chromatography (HPLC) for the separation and determination of metal ions has increased in recent years. [1][2][3][4][5] HPLC is very popular and not as expensive an apparatus; the running cost is very low. In addition, operation of the HPLC is easy, and a more sensitive quantitative analysis is possible by combining precolumn derivatization HPLC with a simple solvent extraction.…”

Section: Introductionmentioning

confidence: 99%

Selective Determination of Iron Ion in Tap Water by Solvent Extraction with 3,4-Dihydro-3-hydroxy- 4-oxo-1,2,3-benzotriazine, Followed by Reversed Phase HPLC

Journal of Liquid Chromatography & Related Technologies

Fujita

Fujii

2008

A selective determination method for Iron (Fe) ion in tap water has been developed by solvent extraction, followed by reversed phase HPLC with photometric detection. The Fe(III) ion was quantitatively extracted into chloroform over the pH range of 3.2 to 4.3 as 3,4-dihydro-3-hydroxy-4-oxo-1,2,3-benzotriazine (DHOB) chelate. Job's method indicated that the Fe-DHOB chelate composition was Fe(DHOB) 3 . The molar absorptivity of the Fe-DHOB chelate was calculated as 7.6 Â 10 3 at 430 nm. The extracted Fe-DHOB chelate was then separated on a phenyl column with an eluent of methanol=water=0.05 M DHOB (40:20:40, v=v) and detected at 500 nm. The correlation coefficients of the calibration curves obtained with 5 mL Fe standards were about 0.999 over the range of 10 ng=mL (ppb) to 10 mg=mL (ppm). The detection limit of the Fe ion in 5 mL water was estimated as 7 ppb, which corresponded to 3 times the standard deviation of the blank peak area. Effects of foreign ions on the determination of 0.2 ppm Fe ion were investigated with 57 metal ions. Almost none of the ions interfered, except for V(V), Sn(II), and Ti(IV) ions. The recovery with a spiked tap water sample for 0.5 ppm Fe ion (N ¼ 4) was 99.2 AE 0.9%.