608
S. Kinoshita and T. Sunada
was a Shimazu GC-Model 4APE fitted with electron capture detectors. Peak heights were
compared with those from the standard 1 ppm n-hexane solution of PCB as mentioned
above.
Toxicity test
Striped shrimps (Palaemon paucidens), 30—40 mm in length, weighing an average
of 1.4 g each were used as experimental animals for acute toxicity test unless stated
otherwise, and the mortality rate over 24 and 72 hours was observed.
RESULTS AND DISCUSSION
Effect of dose
The concentration of PCB in water was found to be reduced as the administered
gamma dose was increased (Table 1). 100 ppb of PCB in water seems to be a larger concentration than those present in contaminated rivers or lake waters in Japan. Therefore
samples of PCB at a concentration of 50 ppb were irradiated. The results obtained are
shown in Table 1. Gas chromatograms from the extracts of non-irradiated and irradiated
concentrations of Mrad are shown in Fig.l. In thise case, not only was there a similar
r
20 - m m .
ΤΤΓ
IT
Fig. 1.
a) Gas chromatogram of extract from non irradiated solution
b) Gas chromatogram of extract from irradiated solution of 10 Mrad
trend towards a reduction in concentration, similar to the results of irradiation of the 100
ppb solution, but a greater reduction was found when irradiated with the same dose,
which suggested a "dilution effect". But, in irradiating more dilute solutions, such as 1
ppb of PCB, the results obtained were confusing and did not suggest a "dilution effect".
Similar trends had been observed in the irradiation of aqueous solutions of sodium
S. Kinoshita and T. Sunada
was a Shimazu GC-Model 4APE fitted with electron capture detectors. Peak heights were
compared with those from the standard 1 ppm n-hexane solution of PCB as mentioned
above.
Toxicity test
Striped shrimps (Palaemon paucidens), 30—40 mm in length, weighing an average
of 1.4 g each were used as experimental animals for acute toxicity test unless stated
otherwise, and the mortality rate over 24 and 72 hours was observed.
RESULTS AND DISCUSSION
Effect of dose
The concentration of PCB in water was found to be reduced as the administered
gamma dose was increased (Table 1). 100 ppb of PCB in water seems to be a larger concentration than those present in contaminated rivers or lake waters in Japan. Therefore
samples of PCB at a concentration of 50 ppb were irradiated. The results obtained are
shown in Table 1. Gas chromatograms from the extracts of non-irradiated and irradiated
concentrations of Mrad are shown in Fig.l. In thise case, not only was there a similar
r
20 - m m .
ΤΤΓ
IT
Fig. 1.
a) Gas chromatogram of extract from non irradiated solution
b) Gas chromatogram of extract from irradiated solution of 10 Mrad
trend towards a reduction in concentration, similar to the results of irradiation of the 100
ppb solution, but a greater reduction was found when irradiated with the same dose,
which suggested a "dilution effect". But, in irradiating more dilute solutions, such as 1
ppb of PCB, the results obtained were confusing and did not suggest a "dilution effect".
Similar trends had been observed in the irradiation of aqueous solutions of sodium