一、Introduction of isocarbophos
Chemical name: O-METHYL O-[2-(ISOPROPOXYCARBONYL)PHENYL]
PHOSPHORAMIDOTHIOATE
Molecular: C11H16NO4PS
Formula Weight: 289.3
Main
physical and chemical properties: pure isocarbophos is colorless, scaly crystal,
which is soluble in ether, benzene, acetone, acetic ether and insoluble in
water, hard to dissolve in petroleum ether; commercial product of isocarbophos
is mahogany viscous oily liquid which will precipitate crystals when placed.
Content of effective constituent is 85-90%, stable storage in normal
temperature. 40% isocarbophos emulsifiable concentrate is yellow or mahogany
crystal homogeneous oily liquid.
As a kind of commonly and extensively used
insecticide and acaricide, isocarbophos is also called carboxamide phosphorus
and is widely used in pest control of agriculture. However, it is stipulated
that isocarbophos is banned in vegetables. Since January this year, isocarbophos
has been detected in the cowpeas from Hainan province for three times in
agricultural products market of Wuhan, Hubei province. It is obvious that
pesticide with isocarbophos has been used during the vegetable planting, causing
the toxic cowpeas. By now, pesticide residues in the cowpeas from Hainan have
been detected for exceeding the standard in about 11 cities such as Wuhan,
Shanghai, Zhenzhou, Hefei, Hangzhou, Guangzhou, etc.
二、Solutions
Various testing institutes have begun the test of isocarbophos residues since
the “toxic cowpeas”event to ensure the safety of cowpeas. Our company has been
devoted to the research in this area and our product LC310 High-frequency Liquid
Chromatograph can meet the demand for testing the pesticide residues.
Instrument Configurations:
P310 high-pressure infusion pump: 1 set
UV310 ultraviolet-visible
detector: 1 set
7725i manual introduction valve (20ul loop): 1 set
LC310
chromatographic data processing system: 1 set
Kromasil C18 250*4.6mm, 5um,
100A chromatographic column: 1 piece
DT310 chromatographic column oven: 1
set
Solution tray: 1 set
Isopycnal starter kit: 1 set
Pre-treatment devices in Lab
Solution filter (with vacuum pump): 1 set
Solution filter membrane
(organic, hydro, 0.45μm, diameter 50mm)
Sample filters (organic, hydro,
0.45μm, diameter 13mm)
Glass syringe for filtration various
types
Electronic balance (accuracy: 1/100000 and 1/10000)
Ultrasonic
cleaner: 1 set
Nitrogen blowing meter: 1 set
Thermostat water bath: 1
set
Pulp refiner: 1 set
Digital thermostatic drying oven: 1 set
100ml
measuring cylinder with stopper: 5
Aluminum foil: 1 coil
Filter paper: 1
box
Other common pre-treatment equipments in the lab
Laboratory reagents:
Acetonitrile: (AR)
Methyl alcohol: (chromatographic pure)
Acetone:
(AR)
Sodium chloride: (140℃4h baking)
Water: ultrapure water or
redistilled water
Pre-treatment of samples:
Reference: NY/T 761.10-2004 Method for Organophosphorus Pesticide Residues in
Vegetables and Fruits
The sample is extracted in acetonitrile and the
extracted solution will be ready for pesticide analysis after purification,
concentration and filtration processes.
Preparation of standard solution:
Reference: GB24573-2009 isocarbophos
Weigh 0.1g standard sample (accuracy
up to 0.0002g) and put it into 50ml volumetric flask; dilute the standard sample
with methyl alcohol to the scale; 5-minute ultrasonic vibration to fully
dissolve the sample, and cooled to indoor temperature; suck exactly 5ml with
suction pipette from the 50ml volumetric flask, dilute the solution with methyl
alcohol to the scale and shake up.
