• Bulletin of the Korean Chemical Society
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• v.34 no.11
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• pp.3444-3450
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• 2013

Three phase hollow fiber-liquid phase microextraction (HF-LPME), which is faster, simpler and uses a more environmentally friendly sample-preparation technique, was developed for the analysis of Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) in human urine. For the effective simultaneous extraction/concentration of NSAIDs by three phase HF-LPME, parameters (such as extraction organic solvent, pH of donor/acceptor phase, stirring speed, salting-out effect, sample temperature, and extraction time) which influence the extraction efficiency were optimized. NSAIDs were extracted and concentrated from 4 mL of aqueous solution at pH 3 (donor phase) into dihexyl ether immobilized in the wall pores of a porous hollow fiber, and then extracted into the acceptor phase at pH 13 located in the lumen of the hollow fiber. After the extraction, 5 ${\mu}L$ of the acceptor phase was directly injected into the HPLC/UV system. Simultaneous chromatographic separation of seven NSAIDs was achieved on an Eclipse XDB-C18 (4.6 mm i.d. ${\times}$ 150 mm length, 5 ${\mu}m$ particle size) column using isocratic elution with 0.1% formic acid and methanol (30:70) at a HPLC-UV/Vis system. Under optimized conditions (extraction solvent, dihexyl ether; $pH_{donor}$, 3; $pH_{acceptor}$, 13; stirring speed, 1500 rpm; NaCl salt, 10%; sample temperature, $60^{\circ}C$; and extraction time, 45 min), enrichment factors (EF) were between 59 and 260. The limit of detection (LOD) and limit of quantitation (LOQ) in the spiked urine matrix were in the concentration range of 5-15 ng/mL and 15-45 ng/mL, respectively. The relative recovery and precision obtained were between 58 and 136% and below 15.7% RSD, respectively. The calibration curve was linear within the range of 0.015-0.96 ng/mL with the square of the correlation coefficient being more than 0.997. The established method can be used to analyse of NSAIDs of low concentration (ng/mL) in urine.

• Childhood Kidney Diseases
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• v.17 no.2
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• pp.42-48
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• 2013

The urinalysis is an essential part of the diagnostic work-up for kidney disease and other renal system disorders. The dipstick test allows rapid and simultaneous chemical analyses of urine, including factors such as pH, specific gravity, protein, glucose, ketones, occult blood, bilirubin, urobilinogen, nitrite, and leukocyte-esterase. The chemical reactions on dipstick are complicated and can be affected by oxidizing, reducing, and discoloring substances in the urine. Therefore, false positive and false negative results are common in dipstick testing. To obtain reliable results with the dipstick, it is necessary to collect urine cleanly and examine the urine carefully. It is mandatory to clearly understand the principles of dipstick testing to evaluate abnormal findings. If the urine dipstick results suggest hematuria, proteinuria, or urinary tract infection, microscopy of the urine should be performed to confirm the findings.

• Journal of Animal Science and Technology
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• v.64 no.2
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• pp.247-261
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• 2022

Ketosis is associated with high milk yield during lactating or insufficient feed intake in lactating dairy cows. However, few studies have been conducted on the metabolomics of ketosis in Korean lactating dairy cows. The present study aimed to investigate the serum and urine metabolites profiling of lactating dairy cows through proton nuclear magnetic resonance (¹H-NMR) spectroscopy and comparing those between healthy (CON) and subclinical ketosis (SCK) groups. Six lactating dairy cows were categorized into CON and SCK groups. All experimental Holstein cows were fed total mixed ration. Serum and urine samples were collected from the jugular vein of the neck and by hand sweeping the perineum, respectively. The metabolites in the serum and urine were determined using ¹H-NMR spectroscopy. Identification and quantification of metabolites was performed by Chenomx NMR Suite 8.4 software. Metabolites statistical analysis was performed by Metaboanalyst version 5.0 program. In the serum, the acetoacetate level was significantly (p < 0.05) higher in the SCK group than in the CON group, and whereas acetate, galactose and pyruvate levels tended to be higher. CON group had significantly (p < 0.05) higher levels of 5-aminolevulinate and betaine. Indole-3-acetate, theophylline, p-cresol, 3-hydroxymandelate, gentisate, N-acetylglucosamine, N-nitrosodimethylamine, xanthine and pyridoxine levels were significantly (p < 0.05) higher in the urine of the SCK group than that in the CON group, which had higher levels of homogentisate, ribose, gluconate, ethylene glycol, maltose, 3-methyl-2-oxovalerate and glycocholate. Some significantly (p < 0.05) different metabolites in the serum and urine were associated with ketosis diseases, inflammation, energy balance and body weight. This study will be contributed useful a future ketosis metabolomics studies in Korea.

• Bulletin of the Korean Chemical Society
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• v.31 no.8
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• pp.2322-2328
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• 2010

A multiple solid-phase extraction (SPE) method was used with liquid chromatography, coupled with mass spectrometry (LC/MS), for the analysis of heterocyclic amines (HCAs) in human urine. Separation efficiencies based on the pH of the mobile phase and the types of columns were compared. An amide column showed better baseline separation and narrower HCA peak widths at pH 5.0 for the mobile phase than a $C_8$ column. Each SPE step, HLB, MCX, and HybridSPE, was optimized by controlling the pH conditions. The combined method with the three SPEs effectively removed interfering species that cause ion-suppression during HCA detection. Validation of the method, performed with SIM and SRM detection, showed correlation coefficients above 0.991 in the range 0.3 - 16.7 ng/mL. Recovery rates were 45.4 - 97.3% on the $C_8$ column and 71.8 - 101.4% on the amide column, and method detection limits were 0.11 - 0.65 ng/mL on the $C_8$ column and 0.12 - 0.48 ng/mL on the amide column. This method using multiple SPEs offers significant benefits for high-throughput determination of HCAs in urine.

• Bulletin of the Korean Chemical Society
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• v.22 no.7
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• pp.685-688
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• 2001

A gas chromatography/mass spectrometric assay method has been developed for the simultaneous determination of benzidine (BZ), N-acetyl benzidine (ABZ) and N,N-diacetyl benzidine (DABZ) in rat urine. BZ, ABZ and DABZ were extracted from urine at pH 8 with ethyl ether. Conjugated urinary metabolites were extracted at pH 8 after hydrolysis with 1 M HCl for 30 min at 100 $^{\circ}C.$ The dried extract was dissolved in 100 ${\mu}{\ell}$ of ethylacetate and then injected in gas chromatography-mass spectrometric (GC-MS) system without further purification or modification. BZ, ABZ and DABZ have good chromatographic properties and offer very sensitive response for the EI-MS (SIM) without any derivatization. The recoveries for BZ, ABZ and DABZ were about 98.0, 81.8 and 71.4%, respectively, at pH 8.0 and the concentration of 5.0 ng/mL. The coefficients of variation of BZ and ABZ were less than 9.5% from 0.1 to 100 ng/mL and that of DABZ was less than 13% in the same concentration range. The detection limits of the assay were 0.01 ng/mL for both BZ and ABZ, and 0.05 ng/mL for DABZ in urine or plasma 1.0 mL.

• Asian-Australasian Journal of Animal Sciences
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• v.33 no.12
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• pp.1940-1947
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• 2020

Objective: Combination of two stressors on alteration of mineral footprints in animals needs due attention to meet maximum production and welfare, particularly in grazing sheep. This study tested whether ewes (Ovis aries) exposed to water deprivation and thermal-humidity stressors had altered mineral footprints in their wool, serum, urine, and feces. Methods: Nine ewes (age = 3 years; mean body weight = 41±3.5 kg) were divided among a control group with free access to water, and treatment groups with water deprivation lasting either 2 h (2hWD) or 3 h (3hWD) after feeding. Using a 3×3 Latin square design, animals were assigned to treatment groups for three sampling periods of 21 days each (n = 9). Blood was collected by jugular venipuncture. Wool was collected at the end of periods 2 and 3. Metabolic crates designed with metal grated floors were used for urine and feces collection. We measured sodium (Na), magnesium (Mg), phosphorus (P), chloride (Cl), calcium (Ca), manganese (Mn), copper (Cu), iron (Fe), and zinc (Zn). Results: The wool mineral levels did not differ between the treatment groups, although K was marginally lower (p = 0.10) in the 2hWD group. The serum and urine mineral levels did not differ between the treatments (p>0.05). Fecal K was significantly lower in the 2hWD group than in the other groups (p≤0.05). Conclusion: In conclusion, water deprivation and thermal-humidity exposure altered the excretion of K, but not of other minerals, in the wool, urine, feces, or serum of ewes. Thus, no additional mineral supplementation is needed for water deprived ewes during thermalhumidity exposure.

• Journal of Veterinary Clinics
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• v.21 no.3
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• pp.264-269
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• 2004

A retrospective analysis was performed with 270 cases of canine urolithiasis examined at Laboratory of Clinical Pathology, College of Veterinary Medicine, Seoul Nat'l University in the period between January 2001 and December 2003. The Shih-Tzu (64 cases), Yorkshire terrier (60 cases), miniature schnauzer (41 cases) and maltese terrier (36 cases) had higher incidences than other breeds. Canine urolithiasis occurred from 4 months to 15 years of age, but the most prevalent age was 3 years. Mean age was $5.68\pm3.14$ years. The major mineral component. of calculi was struvite (54.1%) and calcium oxalate (30.4%). There was no sex prevalences: male 131 cases, female 132 cases. The most prevalent anatomic locations of calculi were urinary bladder (53 of 131 cases), urethra (24 of 131 cases) and bladder/urethra (45 of 131 cases) in males and urinary bladder (103 of 132 Cases) in females. The major mineral component of calculi in urinary bladder was struvite (102 of 160 cases), and that in urethra (13 of 25 cases) and multiple locations (29 of 62 cases) was calcium oxalate: The major components of calculi were not always consistent with the components which could be expected from urine pH and crystals. So it is suggested that the components of the calculi must be analyzed after surgical removal to prevent the recurrence when the calculi could not be dissolved by diets or urine pH modifiers.

• Analytical Science and Technology
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• v.15 no.3
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• pp.185-189
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• 2002

International Olympic Committee (IOC) prohibits the use of cyclofenil for male. To prove whether cyclofenil product was taken or not, the analytical method in urine using GC/MS was established. The extraction recoveries of cyclofenil and its metabolites were higher in the range of pH 5-9. Because the parent drug (cyclofenil) was not excreted in urine, metabolites were detected and theses were used as a criteria of cyclofenil dose. Therefore the metabolites were hydrolyzed, extracted at pH 9.6, derivatized with MSTFA and analyzed by GC/MS.

• Journal of Animal Environmental Science
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• v.5 no.3
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• pp.171-174
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• 1999

This study was conducted to investigate the quantity and characteristics of manure and urine produced by lactating sow fed commercial diet for 24 days. 3 way cross bred 10 lactating sows with litters were alloted at farrowing pen. Crude protein and digestible energy were 14% and 3,467 kcal in diet, respectively. Average body weight of sow was 237.5kg. Feces with urine was produced 6.98kg per day by lactating sow ranging from 5.72 to 7.93kg. Manure solid was produced 2.75 kg per day ranging from 2.17 to 3.87kg and urine 4.23kg per day ranging from 3.55 to 4.06kg, respectively. Dry matter of feces and urine were 29.91 and 1.54%, respectively. Nitrogen and phosphorus contents in fresh feces were 0.86 and 0.30%, respectively. Nitrogen content in urine was 0.86, and phosphorus in urine was 0.47%. pH in manure was 6.73 and in urine was 8.38 respectively. Biochemical oxygen demand and suspended solid in urine were 5,196 and 308mg/$\ell$, respectively.

• Journal of Veterinary Clinics
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• v.22 no.4
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• pp.357-364
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• 2005

We surveyed the incidence of urinary calculi for feeding period, urinary lesion, composition of calculi and changes of serum chemistry with Korean native castrated steers, which are growing until 26 through 31 months. Without showing any clinical signs such as urethral obstruction, hydronephrosis and strangury for all group, $37.8\%$ (34 out of 90) of Korean native steers carried urinary calculi in carcass. The incidence of urine calculi far different feeding stages from 26 to 31 months were observed as $13.3-60.0\%$er, no significant differences were detected. The distribution of calculi were kidney $(24.4\%)$, kidney and bladder $(10\%)$ and kidney, bladder and urine $(3.3\%)$. Congestion of urinary bladder was shown in $26.6\%$ of Korean native steers. Korean native steers with urinary calculi $(41.2\%)$ had more possibilities (P<0.05) to bring outbreaks of congestion of urinary bladder than those of without calculi $(17.8\%)$. The main composition of calculi were struvite (magnesium ammonium phosphate crystals), calcium phosphate, calcium carbonate, calcium oxalate, non-oxalate calcium, ammonia and phosphate. The distribution of urine pH was $71.7\%$(above pH 8.0), $12.2\%$ (between pH 7.0 and pH 8.0) and $16.6\%$ (under pH 7.0). Like shown in herbivores, most of the urine pH was distributed as alkaline urine. Serum creatinine was shown significant difference (P<0.05) according to incidence of calculi but other serum chemistry didn't show any difference in serum chemistry. These results suggest that feeding until 26 to 31 months in Korean native steers castrated at 6 months of the age elicits urinary calculi and congestion of urinary bladder, but not clinical abnormality. And adjustment of the dietary Can ratio to a level of 2:1 or greater during feeding period may reduce the possibility of incidence of urinary calculi in Korean native steers.