ABSTRACT
OBJECTIVE： To establish a method for simultaneous determination of residual methanol， ethanol， acetonitrile， isopropanol， methylbenzene， tetrahydrofuran and ethyl acetate in Nilethylenol raw material. METHODS： GC was performed. The determination was performed on DB-WAX capillary column. The detector was hydrogen flame ionization detector with split ratio of 5 ∶ 1. The carrier gas was nitrogen （purity： 99.999％） at the flow rate of 1.0 mL/min. The sample size was 1 μL， directly sampling with bonded crosslinked polyethylene glycol as stationary phase. The initial temperature was 40 ℃ and was maintained for 5 min， increased to 90 ℃ at 10 ℃/min， and then increased to 200 ℃ at 5 ℃/min. The temperature of injector was 220 ℃， and detector temperature was 230 ℃. RESULTS： The linear range was 0.24-12.00 μg/mL for methanol （r＝0.999 7）， 0.40-20.00 μg/mL for ethanol （r＝0.999 5）， 0.033-1.64 μg/mL for acetonitrile （r＝0.999 8）， 0.40-20.00 μg/mL for isopropanol （r＝0.999 5）， 0.071-3.56 μg/mL for methylbenzene （r＝0.999 6）， 0.058-2.88 μg/mL for tetrahydrofuran （r＝0.999 8）， 0.40-20.00 μg/mL for ethyl acetate （r＝0.999 7）， respectively. The limits of quantitation were 0.24， 0.40， 0.033， 0.40， 0.071， 0.058， 0.40 μg/mL， respectively. The limits of detection were 0.08， 0.10， 0.01， 0.13， 0.02， 0.02， 0.13 μg/mL， respectively. RSDs of precision， stability and reproducibility tests were all lower than 2％. The recoveries were 98.17％-100.48％ （RSD＝0.92％，n＝9）， 97.77％-101.30％（RSD＝1.32％，n＝9）， 97.56％-100.85％（RSD＝1.20％，n＝9）， 98.64％-100.92％（RSD＝0.87％，n＝9）， 98.54％-100.62％（RSD＝0.76％，n＝9），98.26％-100.00％（RSD＝0.74％，n＝9）， 98.30％-100.59％（RSD＝0.76％，n＝9）， respectively. CONCLUSIONS： The method has high sensitivity and good accuracy， and can be used for the simultaneous determination of residual methanol， ethanol， acetonitrile， isopropane， methylbenzene， tetrahydrofuran and ethyl acetate in Nilethylenol raw material.
ABSTRACT
OBJECTIVE:To establish a method for simultaneous residual determination of dichloromethane and ethyl acetate in bisacodyl raw material. METHODS:Head-space GC was performed on the capillary column of 6% cyanopropyl phenyl-94% di-methyl polysiloxane(DB-624)by temperature programming,the temperature of injector was 220 ℃,detector was flame ionization detector with temperature of 250 ℃,carrier gas was high purity nitrogen with the flow rate of 3.0 ml/min,split ration was 1∶10, headspace heating temperature was 70 ℃,equilibration time was 30 min,volume of headspace vial was 5 ml,and the injection volume was 1 ml. RESULTS:The linear range was 6-120μg/ml for dichloromethane(r=0.999 9)and 50-1 000μg/ml for ethyl ac-etate(r=0.999 9);the limit of quantitation was 0.2,1.7 μg,limit of detection was 0.06,0.5 μg;RSDs of precision,stability and reproducibility tests were no higher than 3%;recoveries were 100.30%-102.00%(RSD=0.63%,n=9) and 100.10 %-101.30%(RSD=0.44%,n=9). CONCLUSIONS:The method is simple and accurate,and can be used for the simultaneous residual deter-mination of dichloromethane and ethyl acetate in bisacodyl raw material.
ABSTRACT
OBJECTIVE:To establish the method for the residual determination of 7 organic solvents in picrosideⅡraw materi-als. METHODS:Head-space GC was performed on the capillary column of 6% cyanopropyl phenyl-94% dimethyl polysiloxane (DB-624) by temperature programming,the temperature of injector was 200 ℃,temperature of flame ionization detector was 250 ℃,the flow rate of N2 was 35 ml/min,and split ration was 10∶1,headspace sampling was adopted with the volume of 1 ml, the heating temperature of headspace sampling was 85 ℃,heating time was 45 min. RESULTS:The good linear relationship of methanol,ethanol,ethylacetate,methylbenzene,benzene,phenylethylene and divinglbenzene had been obtained(r=0.999 6-0.999 9);RSDs of precision stability test were less than 3%;average recoveries was in the range of 78.0%-104.9%(RSDs were 0.65%-2.47%,n=6)respectively. CONCLUSIONS:The method is specific,rapid,simple and accurate,and can be used for the determination of residual organic solvents in picrosideⅡraw materials.