Skuland I L, Andersen T, Trones R, Eriksen R B, Greibrokk T
Department of Chemistry, University of Oslo, P.O. Box 1033 Blindern, N-0315 Oslo, Norway.
J Chromatogr A. 2003 Sep 5;1011(1-2):31-6. doi: 10.1016/s0021-9673(03)01186-5.
Polyethylene glycol (PEG) 20000 in low-density polyethylene has been determined using column switching and inverse temperature programming in reversed-phase packed capillary liquid chromatography with evaporative light scattering detection. PEG 20000 was extracted into water from the polyethylene dissolved in toluene and PEG 35000 was added as an internal standard (I.S.). The samples in aliquots of 100 microl were reconcentrated on the enrichment column using a loading mobile phase of acetonitrile-water (3:97, v/v) at a flow-rate of 75 microl/min for 3 min, then back-flushed and separated on the analytical column with acetonitrile-THF-water (40:5:55, v/v) as mobile phase. The column temperature was reduced from 68 to 55 degrees C with a ramp of -1.5 degrees C/min, held constant for 3 min and then reduced further to 45 degrees C with a -1.5 degrees C/min ramp and kept constant for 1 min. The analysis runtime was 20 min. The recovery of PEG 20 000 was determined to 65.1% with 2.8% RSD and the mass limit of detection of PEG 20 000 was 1.25 microg. The within-assay and between day precision of the retention times of both PEG 20000 and PEG 35000 displayed RSD of less than 1.1% (n = 9), while the overall area ratio RSD of 100 microg/ml PEG 20000 over PEG 35000 was 1.3% (n = 9). The method was linear within the investigated concentration range 25-125 microg/ml (R2 = 0.9983). In addition, a mixture of PEG 4000, 8000, 10000, 20000 and 35000 was analysed on the system to demonstrate the possibility of analysing several PEGs in a sample with the use of temperature gradient elution.
采用柱切换和反相温度程序控制，结合蒸发光散射检测，在反相填充毛细管液相色谱中测定了低密度聚乙烯中的聚乙二醇（PEG）20000。将溶解于甲苯中的聚乙烯中的PEG 20000萃取到水中，并加入PEG 35000作为内标（I.S.）。取100微升等分试样，使用乙腈-水（3:97，v/v）的进样流动相，以75微升/分钟的流速在富集柱上进行再浓缩3分钟，然后反冲，并在分析柱上以乙腈-四氢呋喃-水（40:5:55，v/v）作为流动相进行分离。柱温以-1.5℃/分钟的斜率从68℃降至55℃，保持3分钟，然后再以-1.5℃/分钟的斜率进一步降至45℃并保持1分钟。分析运行时间为20分钟。测定PEG 20000的回收率为65.1%，相对标准偏差为2.8%，PEG 20000的质量检测限为1.25微克。PEG 20000和PEG 35000保留时间的批内和批间精密度的相对标准偏差均小于1.1%（n = 9），而100微克/毫升PEG 20000与PEG 35000的总面积比相对标准偏差为1.3%（n = 9）。该方法在所研究的25-125微克/毫升浓度范围内呈线性（R2 = 0.9983）。此外，在该系统上分析了PEG 4000、8000、10000、20000和35000的混合物，以证明使用温度梯度洗脱分析样品中多种PEG的可能性。
