Urine spectra

Description of Method. Quinine is an alkaloid used in treating malaria (it also is found in tonic water). It is a strongly fluorescent compound in dilute solutions of H2SO4 (f = 0.55). The excitation spectrum of quinine shows two absorption bands at 250 nm and 350 nm, and the emission spectrum shows a single emission band at 450 nm. Quinine is rapidly excreted from the body in urine and is easily determined by fluorescence following its extraction from the urine sample. 

These agents have broad-spectrum activity against both gram-negative and gram-positive bacteria. They provide high urine and tissue concentrations and are actively secreted in reduced renal function. Switch to oral when possible due to excellent bioavailability. 

A 43-year-old male in the surgical ICU after exploratory laparotomy following a motor vehicle accident develops fever that is unresponsive to broad-spectrum antibacterial therapy (piperacillin-tazobactam 3.75 g every 6 hours, gentamicin 120 mg every 8 hours, and vancomycin 1 g every 12 hours). The patient has a central venous catheter and a Foley catheter. Blood cultures are negative at the time, but the patient has yeast growing in the sputum and urine. Laboratory studies reveal a white blood cell count of 11,300 cells/mm3 (11.3 x 109/L). 

The mass spectrum of aspirin has been used as an aid in the rapid identification of toxic materials isolated from urine, blood or gastric aspirates of drug abuse patients.36> 37... 

Figure 6.43 H spectrum of diclofenac glucuronide obtained after single trapping from a 100 pi injection of female urine 4 h after dosage of 50 mg of diclofenac. The spectrum was recorded using a cryogenic flow probe at 600 MHz. The spectrum indicates that the sensitivity is sufficient to run aU two-dimensional experiments needed for structure elucidation. Reproduced from [82] with permission from Elsevier.

Bioavailabihty of 38% and has similar antimicrobial spectrum as erythromycin but is more effective than erythromycin on gram-negative bacteria. Mostly excreted in feces although some low levels (approximately 6%) of the parent compound are excreted through the urine. 

It is orally effective broad spectrum imidazole antifungal drug. It is useful in both dermatophytosis and deep mycosis. Oral absorption is facilitated by gastric acidity. It is highly protein bound, metabolised in liver and metabolites are excreted in urine and faeces. Its spectrum is similar to that of miconazole and is more active against Coccidioides. 

Unknown compounds are detected frequently, and laboratories eventually develop some level of comfort in recognizing them as artifacts that are not significant clinically, at least for the purpose of ruling out a possible inborn error of metabolism [21]. However, there are instances when an unknown compound is found in multiple specimens from the same patient and cannot be associated with ongoing drug and known dietary intake. This was the set of circumstances that led to the identification of 2-octenylsuccinic acid as the compound referred to by some laboratories as pseudo-orotic acid [11, 18]. On the other hand, the spectrum shown in Fig. 3.1.10, tentatively identified as 4-hydroxy 2-hexenoic acid by GC-MS/MS, belongs to a compound that appears in the urine of patients with disorders of propionate me-... 

Fig. 7.4.3a,b Nuclear magnetic resonance (NMR 500 MHz) urine spectra from a patient with severe trimethylaminuria, a Before eating sea fish (TMA = 44 pmol/mmol creatinine, TMA N-oxide not detectable), b After a 300-g sea fish meal [Nijmegen protocol urine collection during the 6-h postprandial period TMA = 322 pmol/mmol creatinine, TMA N-oxide (TMA + TMA N-oxide) = 84%]. The NMR spectrum shows the presence of increased TMA in the pre-load sample as well as the absence of TMA N-oxide. After eating fish the TMA concentration is very high and the ratio is clearly abnormal... 

Carbaryl [65-25-2], 1-naphthyl ZV-methylcarbamate (111) (mp 142°C, d 1.232 g/cm3, vp 0.67 Pa at 20°C), is ca 95% pure as the technical grade and is soluble in water to 120 mg/L. Carbaryl has a rat oral LD5Q of 540 mg/kg and a dermal LD50 of >2000 mg/kg. It is a broad-spectrum insecticide registered on more than 100 crops. Carbaryl is rapidly detoxified and eliminated in animal urine and is neither concentrated in fat nor secreted in the butterfat of milk, thus it is favored for application to food crops. 

Explicit models require comprehensive input in the calibration phase either the actual spectrum of each pure component or the full chemical breakdown for many training samples. The success of these methods is greatly compromised if the calibration information is incomplete or inaccurate. For samples with many components, such as most whole blood, blood serum, and urine specimens, explicit modeling is an inefficient approach when only one or a subset of the full number of chemicals is of interest. 

Representative spectra of blood serum samples, processed as described above to remove broad fluorescent background via a polynomial, are shown in Fig. 16.6, along with similar samples of urine (data from Qi and Berger [5]). Serum spectra contain many more visible Raman peaks than urine, whose spectrum is dominated by a single urea peak. 

Fig. 16.6. Representative Raman spectra, after background subtraction, of blood serum (above) and urine (below). Spectra from multiple subjects are shown (data replotted from [5]). The spectrum of blood serum contains many chemical signatures at comparable amplitudes, whereas that of urine is dominated by a urea peak...

Figure 6.11. Mass defect plots of human biological matrices obtained from high-resolution LC-MS data (a) plasma, (b) bile, (c) feces, and (d) urine. LC-MS data from each biological matrix were combined into one spectrum to generate the mass defect plots, (e) Mass defect plot of 115 marketed drugs. The dotted circle in each plot represents the dense population of the mass defects of 115 marketed drugs.

Figure 4.2 (a) The 19F NMR spectrum of a sample of human urine collected from 0-4 h after dosing with 1000 mg BW935U83 and (b) the corresponding 1 H NMR spectrum of the same sample... 

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