Residual Solvents calculation in GC

1.0 OBJECTIVE 

To lay down the procedure for the Residual Solvents calculation in GC

2.0 SCOPE

This SOP is applicable to Residual Solvents calculation in GC

3.0 BACKGROUND 

NIL

4.0 RESPONSIBILITY

4.1 QC-Chemist 

4.2 Head-QC

5.0 PROCEDURE

5.1 For this i have taken residual solvents(Ethanol, IPA, Acetonitrile, Ethyl acetate, Toluene, Acetic acid) in the memantine Hydrochloride.

5.2 Chromatographic Conditions:
Instrument is Agilent 6890 N, Column AT-624, 30x 0.53x 3 microns, injector Temperature is 140 degrees, split  is 1:5, Detector Temerature 260 degrees(FID), Carrier gas is helium, Column flow is 2.8 PSI, Load is 1 microleter, diluent is N,N dimethyl acetamide and Column is programmed in the following way
Rate(degree/min) Temperature(degrees) Hold Time(Min)
-- 40 10
6 130 5
35 240 11
5.3 Sample preparation: 200 mg of sample in 10 ml, dissolve, dilute to volume with diluent(20 mg/ml).

5.4 Standard Preparation:

Solution -I: Transfer 127 microliters of Ethanol, 127 microliters of IPA, 11 microliters of Acetonitrile, 111 microliters of Ethyl acetate, 21 microliters of Toluene, 95 microliters of Acetic acid  in 10 ml volumetric flask dilute with diluent.

Solution-II:  transfer 0.1 ml of solution-I into 10 ml Volumetric flask. This solution gives 5000 ppm of ethanol, 5000 PPM of IPA, 410 PPM of ACN, 5000 PPM of ethyl Acetate, 890 PPM of Toluene, and 5000 PPM of acetic acid with respect to 20mg/ml of sample preparation.

5.5 Calculate each solvent with following the formula

B1 is area of  solvent in the blank

5.6 Typical chromatograms for Standard and Sample solution:

Standard Solution Chromatogram

Sample solution Chromatograms
5.7 Let us start the calculation

Standard Areas of 2 injections(After subtracting from Blank)
STDEthanol IPAAcetonitrileEthyl acetateTolueneAcetic acid

169889186930225511497257556777700

170012185890226891466787321276890
sum33990137282045240296403148779154590
Average169950.518641022620148201.574389.577295
* Note: I am taken only two injections for calculation
Samples area of two injections (After subtracting from Blank)
SampleEthanol IPAAcetonitrileEthyl acetateTolueneAcetic acid

1866237885733015260

1922226745660016340
sum37884646211393031600
Average1894232315696.5015800

5.8 Solvent densities:

Solvent Specific gravity       
Pentane 0.626
Petroleum ether 0.656
Hexane 0.659
Heptane 0.684
Diethyl amine 0.707
Diethyl ether 0.713
Triethyl amine 0.728
Tert-butyl methyl ether 0.741
Cyclohexane 0.779
Tert-butyl alcohol 0.781
Isopropanol 0.785
Acetonitrile 0.786
Ethanol 0.789
Acetone 0.790
Methanol 0.791
Methyl isobutyl ketone 0.798
Isobutyl alcohol 0.802
1-Propanol 0.803
Methyl ethyl ketone 0.805
2-Butanol 0.808
Isoamyl alcohol 0.809
1-Butanol 0.810
Diethyl ketone 0.814
1-Octanol 0.826
p-Xylene 0.861
m-Xylene 0.864
Toluene 0.867
Dimethoxyethane 0.868
Benzene 0.879
Butyl acetate 0.882
1-Chlorobutane 0.886
Tetrahydrofuran 0.889
Ethyl acetate 0.895
o-Xylene 0.897
Hexamethylphosphorus triamide 0.898
2-Ethoxyethyl ether 0.909
N,N-Dimethylacetamide 0.937
Diethylene glycol dimethyl ether 0.943­
N,N-Dimethylformamide 0.944
2-Methoxyethanol 0.965
Pyridine 0.982
Propanoic acid 0.993
Water 1.000
2-Methoxyethyl acetate 1.009
Benzonitrile 1.01
1-Methyl-2-pyrrolidinone 1.028
Hexamethylphosphoramide 1.03
1,4-Dioxane 1.033
Acetic acid 1.049
Acetic anhydride 1.08
Dimethyl sulfoxide 1.092
Chlorobenzene 1.1066
Deuterium oxide 1.107
Ethylene glycol 1.115
Diethylene glycol 1.118
Propylene carbonate 1.21
Formic acid 1.22
1,2-Dichloroethane 1.245
Glycerin 1.261
Carbon disulfide 1.263
1,2-Dichlorobenzene 1.306
Methylene chloride 1.325
Nitromethane 1.382
2,2,2-Trifluoroethanol 1.393
Chloroform 1.498
1,1,2-Trichlorotrifluoroethane 1.575
Carbon tetrachloride 1.594
Tetrachloroethylene 1.623

Weight of the sample: 199.98
dilution of the sample : 20 mg /ml

Ethanol =

(1894/ 169950) * (127 micro liters x0.789 g/ml  /10) * (0.1/10) * (20 mg/ml/ 199.98 mg) * 1000000
 = 56.48 PPM 

IPA=

(23231/ 186410) * (127 micro liters x0.785 g/ml  /10) * (0.1/10) * (20 mg/ml/ 199.98 mg) * 1000000
 =  621.27 PPM

Like that you can calculate PPM obtained for other solvents

6.0 ANNEXURES
Nil


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