null232,.;,;srz J.;0, 2009, 21(6): 817-820. (Lin Zhaoxiang, LiJie, Liu Lin-me,i eta.l Laser-induced breakdown spectroscopy for analysis of soilelements.H igh P ow er L aser and P article B eam s, 2009, 21(6): 817-820) 6 null-=,d?,S,.;K+Ys J.;, 2009, 4(4): 1126-1130. (Yao Shunchun, Lu Jidong,296;023Lu Zhim in, et a.l The impactof samplemorphology on laser ablation properties of coa.l A cta Optica S in ica, 2009, 4(4): 1126-1130) 7 null,d?,.;,;Ess J., 2009, 30(2): 229-332. (Xie Chengl,i Lu Jidong,LiPengyan, et a.l Quantitative analysis of ash component in coalby laser induced breakdown spectroscopy. Journa l of Eng ineering Therm ophysics,2009, 30(2): 329-0332)8 null Body D, Chadw ick B L. Optim ization of the spectraldata processing in a LIBS simultaneous elemental analysis system J. Spec trochim ica A cta PartB, 2001, 56(6): 725-736. 9 null Body D, Chadwick B L. Simultaneous elemental analysis system using laser induced breakdown spectroscopy J. R eview of S cientif ic Instrum en ts,2001, 72(3): 1625-1629.10nullSS9_.rsZEM .:SS, 1992: 3-5. (ChinaEnvironmentalM onitoring Station. Modernelements analysis ofsoil in China. Beijing: ChinaEnvironmentalScience Press, 1992: 3-5) 11 null NationalInstitute ofStandards and Technology. http: /www. nist. gov/OL. 12 null.08?;sM .:, 2005: 116-123. (Xin Renxuan. Plasma em ission spectrometry. Beijing: BeijingChem icalIndustry Press, 2005: 116-123) 13 null PasquiniC, Cortez J, SilvaLM C, et a.l Review of laser induced breakdown spectroscopy J. J Braz Ch em S oc, 2007, 18(3): 463-512.Determination of potassium concentrations in compoundfertilizerwith laser induced breakdown spectroscopyChen Ka,i null Lu Jidong( School of E lectric Power, South China U niver sity of T echnology, Guangzhou 510640, Ch ina)null null Abstract: null Laser induced breakdown spectroscopy ( LIBS) has been used to analyze the concentration of potassium in compoundfertilizer. Sel-f absorptionwas prone toappear in the formation process ofplasmabecauseof thehigh-content potassium in samples. The a-tom ic spectral line 404. 40 nm of potassium was determ ined as the optimized lineby analyzing the excitation energy, transition probabilityand sel-f absorption of spectral lines. Experimental stabilitywith differentaveragenumbers of pulseswas discussed, and the results indica-ted that the averagemeasurement of100 pulses had a lower relative standard deviation. N ine samples were analyzed and seven of themwere tested to establish thecalibration curveofmeasured concentration ofK2O. The linear fittingdegreeof the calibration curvewas 0. 989and themeasured concentration ofK2O in the other two sampleswaswell consistentw ith the corresponding reference concentrationwith anabsolute error of less than 0. 3%.null null K eywords: null laser induced breakdown spectroscopy; null compound fertilizer; null concentration ofpotassium; null sel-f absorption; null quan-titative analysis2972null:gKc;,;s