BACKGROUND: We evaluated the performance of the TOSOH glycohemoglobin analyzer HLC-723GHb V A1c 2.2TM (TOSOH Corp. Kyoto, Japan), a recently introduced automated hemoglobin A1c (HbA1c) analyzer using high performance liquid chromatography (HPLC) method without sample pretreatment. METHODS: The performance characteristics evaluated were precision, linearity, comparison with VARIANTTM (Bio-Rad, Germany) and throughput following NCCLS evaluation protocols (EP5-T2, EP6-P, and EP9-T). RESULTS: The within-run and between-day CV's were 0.910 and 1.328 for low level (6.2%), 1.214 and 1.460 for middle level (8.5%), and 0.789 and 1.449 for high level (10.7%), respectively. We found the perfect linearity of HbA1c (%) from 6.5 to 10.2 (r2=0.9995). Comparison studies between A1c 2.2 and VARIANTTM yielded the following correlation equations; A1c 2.2TM = 0.9915 (VARIANTTM) + 0.1198 %HbA1c (r=0.9936, P < 0.0001). Throughput was 28.0 tests per hour for A1c 2.2TM compared with 15.2 tests for VARIANTTM, which were determined including red blood cell lysis time before sample loading for VARIANTTM. A1c 2.2TM did not need sample pretreatment. CONCLUSIONS: With the above results, A1c 2.2TM shows acceptable performance and is suitable for routine use in the clinical laboratory.
Chromatography, High Pressure Liquid ; Chromatography, Liquid ; Erythrocytes

Eight isoflavonoid compounds were isolated from the EtOAc fraction of Maackia amurensis which had shown the highest anti-Helicobacter pylori activity among the fractions, using medium pressure liquid chromatography and recrystallization. Based on the spectroscopic data including 1H-NMR, 13C-NMR, HMBC and MS data, the chemical structures of the isolates were determined to be (-)-medicarpin (1), afromosin (2), formononetin (3), tectorigenin (4), prunetin (5), wistin (6), tectoridin (7) and ononin (8). Anti-H. pylori activity of each compound was evaluated with broth dilution assay. As a result, (-)-medicarpin (1), tectorigenin (4) and wistin (6) showed anti-H. pylori activity. (-)-Medicarpin (1) exhibited the most potent growth inhibitory activity against H. pylori with the minimal inhibitory concentration (MIC)90 of 25 microM, and tectorigenin (4) with MIC90 of 100 microM ranked the second. This is the first study to show the anti-H. pylori activity of M. amurensis, and it is suggested that the stem bark of M. amurensis or the EtOAc fraction or the isolated compounds can be a new natural source for the treatment of H. pylori infection.
Chromatography, Liquid ; Maackia*

No abstract available.
Chromatography, Liquid* ; Humans*

BACKGROUND: We evaluated the performance and analysis time of HLC-723 G7 (Tosoh corp. Tokyo, Japan) hemoglobin (Hb) A1c autoanalyzer. It utilizes cation exchange high performance liquid chromatography (HPLC) method and has a reduced analysis time compared with that of an earlier model HLC-723GHb V A1c 2.2(TM) (HLC-723GHb V, Tosoh corp. Tokyo, Japan). METHODS: We evaluated linearity, precision and comparison with HLC-723GHb V following NCCLS guidelines and counted the number of tests per hour to estimate analysis time. RESULTS: Linearity through the range from 5.8% to 13.9% was good (r2=0.9930, relative nonlinearity <2.5%). The within-run coefficients of variation (CVs) for groups of low, middle, and high level were 1.09%, 0.76%, and 0.68% and total CVs for each group were 1.60%, 0.91%, and 1.00%, respectively. Correlation equation between HLC-723 G7 and HLC-723GHb V was HLC-723 G7=1.0308 (HLC-723GHb V)-0.2896 %Hb A1c (r=0.9992, P<0.0001). Analysis time of HLC-723 G7 was 1.2 minutes per test compared with 2.1 minutes of HLC-723GHb V. CONCLUSIONS: HLC-723 G7 showed the acceptable performance and shortening analysis time therefore, it was suitable for reducing turn around time of Hb A1c assay.
Chromatography, Liquid ; Hemoglobin A, Glycosylated

High-performance countercurrent chromatography (HPCCC) coupled with reversed-phase high-performance liquid chromatography (RP-HPLC) method was developed to isolate dihydrophaseic acid 3′-O-β-D-glucopyranoside (DHPAG) from the extract of Nelumbo nucifera seeds. Enriched DHPAG sample (2.3 g) was separated by HPCCC using ethyl acetate/n-butanol/water system (6:4:10, v/v/v, normal-phase mode, flow rate: 4.0 mL/min) to give 23.1 mg of DHPAG with purity of 88.7%. Further preparative RP-HPLC experiment gave pure DHPAG (16.3 mg, purity > 98%). The current study demonstrates that utilization of CCC method maximizes the isolation efficiency compared with that of solid-based conventional column chromatography.
Chromatography ; Chromatography, Liquid ; Countercurrent Distribution ; Methods ; Nelumbo

BACKGROUND: Hemoglobin A1c (HbA1c) is widely used for the monitoring of glycemic control. A wide variety of different analytical methods is currently used by clinical laboratories. We performed this study to evaluate the newest ion-exchange high-performance liquid chromatography system, the HLC-723 G7 (Tosoh Corporation, Tokyo, Japan) automated glycohemoglobin analyzer. METHODS: HLC-723 G7 was evaluated for linearity, precision, comparison of method, and speed. HLC-723 G7 was compared with three analyzers including HLC-723 GHb V A1c 2.2, Variant II, and Cobas Integra 800. RESULTS: HLC-723 G7 showed within-run and total imprecision (CVs) of less than 2.5% and excellent linearity to at least 13.0%. HbA1c values obtained from HLC-723 G7 were strongly correlated with those from HLC-723 GHb V A1c 2.2. Comparison with two other methods showed a good correlation but revealed calibration differences throughout the analytical range. HLC-723 G7 required no sample preparation and showed a fast analytical time of 1.6 min. CONCLUSIONS: HLC-723 G7 provides high throughput and excellent precision. However, HbA1c values can differ considerably with different methods or instruments. Therefore, we should be aware of the potential problem in switching the HbA1c testing method
Calibration ; Chromatography, High Pressure Liquid ; Chromatography, Liquid ; Diabetes Mellitus

Amitriptylin hydrochloride is used as the internal standard in place of desipramine hydrochloride to determine the amount of imipramine hydrochloride by HPLC method. Results: Amitriptylin have the same structure as imipramin and the resolution degree between amitriptylin and imipramin is 1.8 while resolution degree between iminodibenzyl and imipramin is very high (R=10.7) because molecule structure of iminodibenzyl do not have branch-circuit. The suitability of chromatographic system through coefficient got high stable results with RSD<1.0%. Amitryptilin hydrochloride can be used as the internal standard in place of desipramine hydrochloride if necessary to test splitting degree in determination of imipramine hydrochloride
Imipramine ; Chromatography ; High Pressure Liquid

To evaluate,the differences of benzidine exposure patterns of the workers in two benzidine-based dye manufacturing factories, the concentration of benzidine: in. air, blood, and urine were measured. The air levels of benzidine dihydrochloride and benzidine-based dye were measured by high performance liquid chromatography with ultraviolet detector. Blood samples were collected at 3 hours after exposure and urine samples were collected at the end of shift. Blood and urine samples were analyzed by high performance liquid chromatography with electrochemical detector. The level of benzidine in reaction process (input, diazotization, and coupling); was 0.381+/-7950 g/m3. The blood benzidine was deteced in 25 workers among 38 in reaction process and their mean levels were 0.0153?0376 ng/mg Hb. The urinary benzidine was detected for 11 workers among 38 workers in the reaction process. The level of benzidine-based dye in drying and packing process was 52.1748+/-4.4111g/m3. The blood benzidine was deteced in 6 workers among 38 in drying and packing process and their mean levels was 0.0062+/-0274 ng/mg Hb. The urinary benzidine was detected for 1 worker among 38 workers exposed to benzidine-based dye. The blood and urinary benzidine were detected in workers exposed to benzidine-based dye. Such results suggested that some part of benzidine-based dye was metaboized to benzidine. Therefore, some regulations for manufacturing and use of the benzidine-based dye are needed to prevent its hazards in industries.
Chromatography, Liquid ; Social Control, Formal

In this study, we measured the activity of the erythrocyte pyrimidine 5'-nucleotidase(P5N) for 83 workers exposed to lead in their workplace, and analyzed the correlation of the activity with other biological exposure indices of lead. The measurement was performed by using a high performance liquid chromatography (HPLC) with a reverse phased ODS column. The results are as follows; 1. The correlation of the erythrocyte P5N activity with the concentration of blood lead(PbB) was shown to be statistically significant (r=-0.71, p=0.0001). 2. For a group of subjects whose PbB was less than 10microgram/dl, the erythrocyte P5N activity was 14.9+/-1.5 micromole uridine/h/g Hb. 3. For medical surveillance, this study suggests the erythrocyte P5N activity of 12 micromole uridine/h/g Hb is equivalent to 40 microgram/dl of PbB. 4. The correlation coefficients of the erythrocyte P5N activity with other biological exposure indices of lead such as PbB, ZPP, ALA-U, PBU, CP-U, ALAD, and log ALAD were -0.71, -0.64, -0.57, -0.51, -0.50, 0.46 and 0.64, respectively. 5. The correlation coefficients of the PbB with other biological exposure indices of lead for ALAD, P5N, ZPP, PBU, CP-U, and ALA-U were -0.76, -0.71, 0.68, 0.59, 0.42, and 0.41, respectively. The erythrocyte P5N activity can be used as a reliable biological exposure index of lead.
5'-Nucleotidase* ; Chromatography, Liquid ; Erythrocytes*

System suitability tests are an integral part of liquid chromatographic technique. They are used to verify the resolution (R) and reproducibility of the analysis to be done. HPLC method for assaying the related substances test of Cefaclor in raw material as well as in pharmaceutical dosage forms introduced to some pharmacopoeia such as EP, USP need to use Delta- 3 cefaclor as the internal standard to verify the suitability of chromatographic system. In case of lacking it to use, Cephalexin can be used as the internal standard in place of Delta-3 cefaclor. cell
Chromatography, High Pressure Liquid ; Cefaclor