7 Other grades may be used, provided it is first ascertained that the reagent is of sufficiently high purity to permit its use without lessening the accuracy of the determination.
Amanye amamaki angase asetshenziswe, uma kutholakala ukuthi kuqala ukuthi i-reagent ihlanzekile ngokwanele ukuvumela ukusetshenziswa kwayo ngaphandle kokunciphisa ukunemba kokuzimisela.