Giusti Pierre, Lobinski Ryszard, Szpunar Joanna, Schaumlöffel Dirk
Group of Bio-Inorganic Analytical Chemistry, CNRS UMR 5034, Hélioparc. Angot, Pau, France.
Anal Chem. 2006 Feb 1;78(3):965-71. doi: 10.1021/ac051656j.
A novel nebulizer (nDS-200) working at sample uptake rates of less than 500 nL min(-1) was developed for a sheathless interfacing of nanoHPLC (75-microm column i.d.) with ICPMS. It was based on a hollow fused-silica needle of which the tip (i.d. 10 microm, o.d. 20 microm) centered in a 254-microm-i.d. sapphire orifice. The nebulizer, equipped with a 3-cm(3) drain-free vaporization chamber, enabled a stable introduction into an ICP of aqueous mobile phases containing up to 95% acetonitrile at eluent flow rates between 50 and 450 nL min(-1). The low dead volume of the interface resulted in a peak width of 1.3 s (at half-height) and the entirely preserved chromatographic resolution. An example application of the coupling to the analysis of a tryptic digest of a SIP18 protein containing two to nine selenomethionine residues was described. The absolute detection limit was 25 fg (80Se), which allowed the detection of low-abundant selenopeptides at the femtomole level. In contrast to electrospray MS, the ICPMS detection in nanoHPLC is unaffected by the coeluting matrix and concomitant compounds and offers an elegant method for the detection and quantification of minor heteroelement-containing species prior to or in parallel with ESI MS analysis.
开发了一种新型雾化器（nDS - 200），用于纳升高效液相色谱（内径75微米的色谱柱）与电感耦合等离子体质谱的无鞘接口，其样品摄取速率低于500纳升/分钟。它基于一根中空熔融石英针，针尖内径10微米，外径20微米，位于内径254微米的蓝宝石孔中心。该雾化器配备一个3立方厘米的无排水蒸发室，能够以50至450纳升/分钟的洗脱液流速，将含高达95%乙腈的水性流动相稳定引入电感耦合等离子体。接口的低死体积导致峰宽为1.3秒（半高宽），色谱分辨率完全得以保留。描述了该联用技术在分析含有2至9个硒代甲硫氨酸残基的SIP18蛋白胰蛋白酶消化产物中的一个应用实例。绝对检测限为25飞克（80Se），这使得能够检测飞摩尔水平的低丰度硒肽。与电喷雾质谱不同，纳升高效液相色谱中的电感耦合等离子体质谱检测不受共洗脱基质和伴随化合物的影响，为在电喷雾电离质谱分析之前或与之并行检测和定量含微量杂元素的物质提供了一种简便方法。
