環(huán)保在線
詳細介紹
因能在pH 1-12范圍內(nèi)操作，這些三鍵鍵合式烷基柱能夠利用pH的能力對可離子化化合物的保留、選擇和靈敏度施加巨大影響，同時還能在低pH和高pH條件下保持優(yōu)異的柱穩(wěn)定性。相比于XBridge BEH C18填料， XBridge BEH C8填料適合分析弱極性物質(zhì)里極性稍強的一類物質(zhì)。
BEH顆粒能夠顯著改善色譜峰形的關(guān)鍵因素是其在合成工藝中 采用了亞乙基橋結(jié)構(gòu)。亞乙基橋連接相鄰的兩個硅醇基，這 不僅增加了顆粒強度，同時也減少了游離的硅醇基位點，從 而減少硅醇基與樣品間不利的相互作用力。傳統(tǒng)的方法(例如 大量的封端(excessive end capping))于封端試劑的空間位阻 效應(yīng)及在活性位點上連接配體。這樣，殘余的游離硅醇基暴 露后就會導致峰展寬和峰拖尾。亞乙基橋可減少游離的硅醇 基數(shù)量，使分子空間排布配體鍵合及封端?？刂七@一 過程可有助于XBridge色譜柱得到的峰形。
色譜柱在低pH流動相中柱壽命差的主要原因是鍵合相在酸性 條件下發(fā)生水解。XBridge填料采用沃特世專有的、的鍵 合技術(shù)與封端技術(shù)，可以在低pH條件下表現(xiàn)出良好的配體穩(wěn) 定性與色譜重現(xiàn)性。通過加速酸性穩(wěn)定性測試，我們發(fā)現(xiàn)與傳統(tǒng)填料相比，XBridge C18色譜柱幾乎沒有發(fā)生保留喪失或峰 形下降的情況，同時具有的柱壽命，而這一特性并不是 通過對固定相進行立體位阻的技術(shù)手段所獲得的。
Evaluation of the change in sphingolipids in the human multiple myeloma cell line U266 and gastric cancer cell line MGC-803 treated with arsenic trioxide
Arsenic trioxide (As2O3) has been found to display anticancer activity against many types of tumors and has been developed into an anticancer drug in clinical treatments. Sphingolipids are membrane lipids that participate in many signal transduction pathways. In this paper, the changes in sphingolipids of the human multiple myeloma cell line U266 and the gastric cancer cell line MGC-803 treated with arsenic trioxide were investigated using an HPLC-ESI–MS/MS method. Analytes were separated by an XBridge BEH C8 column used for Cer, HexCer, LacCer and SM chromatographic separation, and a Capcell PAK MG II C18 column was used for Sph, dhSph, S1P and dhS1P chromatographic separation and gradient elution with acetonitrile–water containing 0.1% formic acid as a phase. A tandem mass spectrometer QTrap in SRM mode was employed in combination with RPLC as a detector for quantitative analysis. The ceramide/sphingolipid internal standard (IS) mixture was used to quantify the levels of sphingolipids. The distributions of sphingolipids were found to be different in the human
品名 | 編號 |
XBridge BEH C8 Column, 130?, 3.5 µm, 2.1 mm X 100 mm, 1/pkg | 186003048 |
XBridge BEH C8 Column, 130?, 3.5 µm, 2.1 mm X 150 mm, 1/pkg | 186003049 |
XBridge BEH C8 Column, 130?, 3.5 µm, 1 mm X 100 mm, 1/pkg | 186003178 |
XBridge BEH C8 Column, 130?, 3.5 µm, 1 mm X 150 mm, 1/pkg | 186003179 |
XBridge BEH C8 Column, 130?, 3.5 µm, 1 mm X 50 mm, 1/pkg | 186003177 |
XBridge BEH C8 Column, 130?, 5 µm, 3 mm X 100 mm, 1/pkg | 186003191 |
XBridge BEH C8 Column, 130?, 3.5 µm, 4.6 mm X 250 mm, 1/pkg | 186003963 |
XBridge BEH C8 Column, 130?, 3.5 µm, 2.1 mm X 50 mm, 1/pkg | 186003047 |
XBridge BEH C8 Column, 130?, 3.5 µm, 2.1 mm X 30 mm, 1/pkg | 186003046 |
XBridge BEH C8 Column, 130?, 3.5 µm, 4.6 mm X 30 mm, 1/pkg | 186003184 |
XBridge BEH C8 Column, 130?, 3.5 µm, 4.6 mm X 75 mm, 1/pkg | 186003185 |
XBridge BEH C8 Column, 130?, 5 µm, 2.1 mm X 150 mm, 1/pkg | 186003013 |
XBridge BEH C8 Column, 130?, 5 µm, 2.1 mm X 30 mm, 1/pkg | 186003187 |
XBridge BEH C8 Column, 130?, 5 µm, 2.1 mm X 50 mm, 1/pkg | 186003011 |
XBridge BEH C8 Column, 130?, 5 µm, 2.1 mm X 100 mm, 1/pkg | 186003012 |
XBridge BEH C8 Column, 130?, 3.5 µm, 3 mm X 30 mm, 1/pkg | 186003182 |
XBridge BEH C8 Column, 130?, 3.5 µm, 3 mm X 50 mm, 1/pkg | 186003050 |
XBridge BEH C8 Column, 130?, 3.5 µm, 3 mm X 150 mm, 1/pkg | 186003052 |
XBridge BEH C8 Column, 130?, 3.5 µm, 3 mm X 100 mm, 1/pkg | 186003051 |
XBridge BEH C8 Column, 130?, 3.5 µm, 4.6 mm X 100 mm, 1/pkg | 186003054 |
XBridge BEH C8 Column, 130?, 3.5 µm, 4.6 mm X 50 mm, 1/pkg | 186003053 |
XBridge BEH C8 Column, 130?, 3.5 µm, 4.6 mm X 150 mm, 1/pkg | 186003055 |
XBridge BEH C8 Column, 130?, 5 µm, 4.6 mm X 250 mm, 1/pkg | 186003018 |
XBridge BEH C8 Column, 130?, 5 µm, 4.6 mm X 150 mm, 1/pkg | 186003017 |
XBridge BEH C8 Column, 130?, 5 µm, 4.6 mm X 100 mm, 1/pkg | 186003016 |
XBridge BEH C8 Column, 130?, 5 µm, 4.6 mm X 50 mm, 1/pkg | 186003015 |
環(huán)保在線