International Journal of Horticulture 2015, Vol.5, No.3, 1
-
12
4
2. Martin's Rose Bengal Agar medium (Martin, 1950)
Glucose
:
10.0 g
Peptone
:
5.0 g
Potassium di hydrogen phosphate
:
l.0 g
Magnesium sulphate
:
0.5 g
Rose bengal
:
33.0 mg
Streptomycin sulphate (10% solution)* :
3.0 ml
Agar
: 15.0 g
Distilled water
:
1000 mL
3. King's B medium (King et al., 1954)
Glycerol
:
10mL
Protease peptone
:
20 g
Dipotassium hydrogen orthophosphate :
1.5 g
Magnesium chloride
:
1.5 g
Ampicillin
:
l000 ppm
Chlorampheicol
:
50 ppm
Cycloheximide
:
10 ppm
Agar
:
15 g
Distilled water
:
1000 mL
Note: * After autoclaving at 121°C for 15 min, cooled and
streptomycin sulphate solution was added.
Herbicide residue analysis
The samples were collected from turmeric field at
harvest to determine the residue of the herbicides. Soil
and turmeric rhizome samples were collected for each
chemical. The protocol details of each herbicide
chemicals are furnished below:.
Method employed for the determination of
herbicides residue in soil and turmeric rhizome
Extraction and analysis of metribuzin
10 g of air dried and 2-mm sieved soil and finely
chopped rhizome samples were transferred into 60 mL
cylindrical tubes. Metribuzin residue was extracted
with 10 ml of acidified acetonitrile (with formic acid)
and 10 ml of methanol by shaking and vertexing for 2
minutes and then sonicating for 30 min. After
sonication 1.8 g of MgSO
4
and 2 g of Na acetate was
added and sample mixture was vigorously shaken for
2 minutes and then centrifuged for 5 min @ 5000
RPM. A 2 ml portion of supernatant solution was
filtered using syringe filter for HPLC analysis.
Instrumental conditions
Instrument
HPLC with DAD (Agilent 1200 series)
Mobile phase
Acetonitrile :Distilled water 70/ 30 v/v
Flow rate
0.5 mL min
-1
Wave length (nm)
230
Injection volume
20 µl (using auto sampler)
Temperature
30
o
C
Column
Eclipse XDB C
18
(5cm, 4.6 x 150 mm)
Retention time
5.32 min (±0.2 min)
