A structural study of the methyleneiminodiacetic acid derivatives of some 7-hydroxycoumarins

✍ Scribed by M.A. Salam Khan; E.F. Mooney; W.I. Stephen

• Publisher: Elsevier Science
• Year: 1968
• Tongue: English
• Weight: 262 KB
• Volume: 43
• Category: Article
• ISSN: 0003-2670
• DOI: 10.1016/s0003-2670(00)89195-3

✦ Synopsis

I53

the sodium analysis is about 0.5% hi&h ; with calcium, the result is about 1.4% hi&. If 7 times this amount of barium or lithium is present, the result is high by 4%.

Sulfate ions cause low results; thus analysis of sodium sulfate gives results 12--17~/~ less than the theoretical amount of sodium. The accuracy of all wet analytical methods for sodium is less in the presence of sulfate, largely because of the insolubility of most sulfates in non-aqueous solvents. The atldition of a lead acetate solution to precipitate the sulfate before adding the socliuln reagent was found to reduce the sodium error to less than 5%. However, tile results were somewhat variable and it would probably be better to eliminate the sulfate from the sample bcforc attempting to carry out an accurate sodium analysis.