Detection of Ziram by LC/APCI/MS

Hiroshi MORIWAKI

Osaka City Institute of Public Health & Environmental Sciences

Ziram

Zn2+

S

S-N

CH3

CH3S

S-

NH3C

H3C

((CH3)2NCS.S)2ZnM.W. 305.8m.p. 240Log Pow 1.09

use pesticideantifouling agent

toxicity endocrine disruptormutagencarcinogen

Analysis of Ziram

Direct detection by GC/MS 　→　 ×

Conventional method

Decomposition of the ligand to CS2

Chemical speciation of dithiocarbamate pesticides ×

LC/MS ( Direct detection of ziram )

Ionization

ESI/MS

Positive ion mode Negative ion mode

× ×

×

×APCI/MS

○

Corona current<0.6A

Corona current>0.6A

Ion mode

A)

B)

Mass spectrum

05000000

1000000015000000

2000000025000000

3000000035000000

40000000

0 1 2 3 4 5 6

Corona current (A)

Pea

k in

tens

ity

Corona current vs. peak intensity

05000000

1000000015000000200000002500000030000000350000004000000045000000

0 10 20 30 40 50

Cone voltage (V)

Pea

k in

tens

ity

Cone voltage vs. peak intensity

Ionization APCI positive ionizationAPCI probe temperature 400 ℃

source temperature 120 ℃capillary voltage 3.0 kVcorona current 1.5 Acone voltage 20 V

desolvation gas flow rate 250 lhr-1 (N2)

Conditions of APCI/MS

column Tosoh TSK-GEL -25002.0× 150mm

mobile phase MeOHflow rate 0.2ml/mincolumn temprature 30℃

Column separation

Mass chromatogram

0

2000

4000

6000

8000

10000

12000

14000

16000

18000

0 5 10 15 20 25

Conc. (g/ ml)

Pea

k in

tens

ity

Calibration curve

Summary

・ Direct detection of Ziram by LC/APCI/MS・ Corona current > 0.6A・ LC separation: GPC column

・ Instrumental detection limit: 2mg/L

Next step

・ Development of the pretreatment・ Use of LC/MS/MS

ref. H. Moriwaki, Y. Yamaguchi and M. Fukushima:Rapid Commun. Mass Spectro., in press (2001).