The use of thermal lensing for the determination of pyrogens.
Based on the optimized spectrophotometric determination of pyrogens (of various classes ( p-aminophenol and endotoxins), thermal lensing was applied to the determination of these substances at the submicrogram level. The limit of detection of p-aminophenol, a pyrogenic impurity in pharmaceutical formulations of paracetamol, by reaction with resorcinol in alkaline solutions is 100 ng mL(-1). Phloroglucinol was considered as an analog of resorcinol as a reagent in this reaction. The conditions of spectrophotometric determination of pyrogenic lipopolysaccharides (endotoxins) by ion-pair formation with methylene blue (the limit of detection is 100 ng mL(-1)), by ion-pair formation with Stains-All (1-ethyl-2-[3-(1-ethylnaphtho[1,2-d]thiazolin-2-ylidene)-2-methylpropenyl]naphtho[1,2-d]thiazolium bromide) (the limit of detection is 500 ng mL(-1)), and by reaction of 2-keto-3-deoxyoctonic acid with thiobarbituric acid (the limit of detection is 800 ng mL(-1)) were proposed. The optimized procedure for 2-keto-3-deoxyoctonic acid was applied for thermal lensing that provided a decrease in the limit of detection to 70 ng mL(-1) and was also used for lipopolysaccharide determination in the endotoxin standard from E. coli.
Orlova
N V
NV
Chemistry Department, M.V. Lomonosov Moscow State University, Vorob'evy Hills, 119992, GSP-2, Moscow, Russia.
Proskurnin
M A
MA
Samburova
V A
VA
Dryagleva
I D
ID
Brusnichkin
A V
AV
D000082:Acetaminophen / Q000737:chemistry; D000627:Aminophenols / Q000032:analysis / Q000737:chemistry; D002232:Carbocyanines; D006358:Hot Temperature; D006801:Humans; D007477:Ions / Q000737:chemistry; D008070:Lipopolysaccharides / Q000032:analysis; D008751:Methylene Blue; D011749:Pyrogens / Q000032:analysis* / Q000737:chemistry; D012118:Resorcinols / Q000737:chemistry; D013057:Spectrum Analysis / Q000379:methods*; D013400:Sugar Acids / Q000032:analysis / Q000737:chemistry; D013858:Thiobarbiturates / Q000737:chemistry
D000627:Aminophenols; D002232:Carbocyanines; D007477:Ions; D008070:Lipopolysaccharides; D011749:Pyrogens; D012118:Resorcinols; D013400:Sugar Acids; D013858:Thiobarbiturates; C002532:2-keto-3-deoxyoctonate; D000082:Acetaminophen; C012040:stains-all; C029684:thiobarbituric acid; D008751:Methylene Blue; C031389:resorcinol